The refurbishment plan

On this page I will be adding some details on the restoration of the small wooden cottage that is being repaired and which will become the radio shack. The walls are built of profiled half logs and the roof is made of clay tiles. It is a very solid little cottage, and I am having a lot of fun to restore it. The photos below provides one with a good idea of the radio shack and its location. The sketches have been made with an old version of Google SketchUp. 

Figure 1. Radio shack viewed from the south-west. The double door to the right provides access to the power room.
Figure 3. Looking north-east, the radio shack can be seen  towards the top right-hand side. This image was captured in the autumn. The main house (also built of logs) is in the centre.
Figure 2. The radio shack is located on the side of a hill, this view is when looking north-west. The radio shack is outside of the view towards the right-hand side of the photo. Some of the Black Wattle (invasive species) visible have since been removed.
Figure 4. View towards the east. There are no major obstructions with high elevations which will adversely affect any  radio transmission or reception from the site. The radio shack is located to the left above the rocky cliff.

Considering Figures 1 to 4 it is clear that the location of the radio shack is well suited for radio communication. It is located in a rural area, distant enough from any town or settlement to avoid the radio frequency (rf) noise generated by low cost switching power supplies and other rf pollution sources. 

There are a number of issues to address before the radio station will be functional. Here is a preliminary list,  it is sure to expand.

Building specific issues:


Radio room issues:

Power room issues:


Radio shack layout

Figure 5. Plan view of the radio shack. This was the basic layout from WW2 until the station was closed down. There was an emergency ex it in the wall, located between the two operators seen in the top left of the sketch. The top left section had an operator position for four Collins TCS sets (1.5 - 12 MHz), their power supplies were stacked below the bench, each had a control box and antenna tuning unit. An antenna switch allowed selection of various antennas ranging from short verticals (~6 m) to end fed wire antennas and dipoles. One could mimic a small radio net with this arrangement as signal strengths, transmit frequency and other characteristics would be different for each TCS set, creating the illusion of an active radio network. They were used in the AM and CW modes. Using CW was noisy due to a relay being keyed, but they got used to that (sort of). A Russian operator at the Luven station translated parts of the technical manual for the TCS sets to create a Russian text of an operator's manual. This eventually found its way back to Russia for printing and distribution to Russian radio operators.

Opposite these 3 transmitters was a British Diplomatic Wireless Service (DWS) MK214D transmitter (crystal/Collins 310B-1 VFO controlled, 1.5 - 26 MHz), this unit could operate in CW mode or carrier controlled AM. The transmitter used 813's in the final stage. This was installed in 1961. The MK214D was not used for any diplomatic traffic and did not use the "Piccolo" system (a multiple frequency shift keying system (MFSK)) as installed at many British embassies; it was used in normal CW and AM modes only. It did receive the DWS Piccolo modification though, which allowed carrier controlled screen-grid modulation, but as far as I could ascertain, the Luven station never had the ancillary electronics to transmit in multi-tone Piccolo mode. Apparently they switched to Piccolo mode when they wanted to transmit AM voice messages. For more details see: 

Figure 6. On the opposite side to the TCS sets were an arrangement of intercept receivers, mainly two British R206 (Mk1), three American RCA AR88 and three Hallicrafters SX28 receivers. These had narrow adjustable crystal filters that allowed the band pass width of the intermediate frequency (IF) of the receivers to be adjusted, so were quite nice to use in any mode (AM/CW) as one could adjust the bandpass filter to remove noise from interfering transmitters. These radios could also be set to the required frequency fairly accurately and were stable enough to not require continuous frequency adjustments. 

To assist with frequency adjustment of either transmitters or receivers, use was made of BC221 frequency meters; these could emit or receive on a selected radio frequency with a very high degree of accuracy. Several of the LM type of frequency meters were also in use, these were very similar to the BC221 but were made by Bendix Radio for the US Navy. These all typically used batteries, which was problematic logistically for the station in Luven, so a small power supply was built to feed all the frequency meters. 

Next to the interception receivers and to the right of the operator were three transmitters. Two of these covered the short wave frequencies (2 - 20 MHz, crystal/VFO controlled (Standard Electric) and (RCA ET4336E, crystal controlled, 4 frequencies switchable, 1942 lab experimental version,  ~1 - 20 MHz) and one covered the lower frequencies (ET4335LF, crystal controlled, 4 frequencies switchable,  1942, covering 60 - 600 kHz). Output power of these were at least 250 watts in either AM or CW. The latter two sets were removed and installed in the old generator room when that was converted to an additional small workshop/radio room.

Directly across from the small workbench was an SSB setup,  installed during 1957. This SSB station was used to communicate with a global network of stations in order to model and predict ionospheric propagation which then enabled efficient scheduling with operators in the field and other purposes. This set-up consisted of two Collins KWS-1 SSB transmitters and four Collins 75A-4 receivers, output of the transmitters were 650 watts each in SSB and CW modes. See Collins Gold Dust Twins for more information. They could be used in a type of AM mode (reinserted carrier, one sideband only) at reduced power, but this was not used as the DWS MK214D could be used for AM transmissions, or even the older WW2 equipment as all were fully functional up to the closure of the station.

Figure 7.  A small workshop area was located to your left as you entered the front door, here one could find some tools, soldering irons, volt and current meters and a cabinet with trays containing some spares (resistors, radio tubes (valves if you are from the UK), capacitors etc.).  During the late 1940's the small worktable was removed to make place for radio equipment..

To the right of the entrance was a shelve containing SSB equipment installed in the 1960's, these were Collins S-line equipment and were used in CW and SSB modes. Power outputs were 100 (bare-foot), 500 (30L-1) or 1000 (30S-1) watts depending on whether and which amplifier was in line or not. These were used for a number of purposes, including to communicate with operators in the field. From WW2 onwards, small field stations were set up on occasion for special operations, these were temporary stations using portable radio equipment (e.g. Collins TCH/18-M transmit/receivers).

The generator room contained two generators, one that was fairly large (diesel) and a smaller low power unit. I have no information as to what exactly was used. Apparently the generators were moved out of the shack to a shed some distance away as the units generated a lot of noise. 

There were some storage cabinets and a small workbench in the generator room (not shown). The camping cot used occasionally was stored in the generator room, I show it here for scale as it was normally folded up and stowed away. The generator room was eventually equipped as a small electronics workshop/store room and additional radio equipment. This allowed the Luven staff to repair equipment and build whatever was required. 

Radio shack update March 2019

Figure 8. Radio shack viewed from the north-west. The area around the shack has been cleared and all rubble removed.
Figure 9. View of the radio shack from the the eastern side. The small cottage has been built in a cut-out dug into shale. We will make a bit of a garden here. I will level the stone floor and remove the shale (it is used for filling on the farm road). No further removal of stone will be allowed.
Figure 10. View of the radio shack from the south-west. I stacked two rock walls to the north of the shack to retain the soil. We planted some plants behind the retaining walls and they will be a good start for a beautiful small garden. What was planted? Ferns and arum lilies (Zantedeschia aethiopica). This lily belongs to the Araceae family. In Afrikaans it is known as the "wit varkoor", literally it can be translated as "white pig ear".  
In the forefront of the photo one can see a red hot poker, also known as the torch lily, knofflers or poker plant. The Afrikaans name is "vuurpyl", (rocket). Kniphofia is a genus of perennial flowering plants that belongs to the family Asphodelaceae. In the summer they are bled dry by the malachite sunbird (Nectarinia famosa). These birds are very pretty with long curved beaks, they are nectarivorous,  and pollinate many flowering plants, especially those with long corolla tubes.
I will add some photos here of the garden as it grows. Some critter dug out half the arum lilies the first day they were planted, these plants have bulbs, which seems to be in some critters'  menu. So I suppose the rule will be to plant enough for yourself and the wild life!

Radio shack update May 2019

Figure 11. The shack is still barren and no equipment has been installed at this time. The cement floor has been sealed and is ready to be overcoated with paint. I have to replace the gas heater unit that was mounted against the wall (where my hat is hanging); this will provide hot water for the shower and basins. The small bathroom will be given a new washbasin, and I need to build a small kitchen cupboard and washbasin combination for the kitchenette.
Figure 12. I did some additional work on the roof. It is now ready for a new coat of paint. I have found a source of new cement tiles, exactly the type that has been installed on the roof, so will be  able to buy some spares.
Figure 13. The fire wall between the radio room and the generator room has been restored. When I renovate the generator room, the other side of the wall will be resurfaced, sealed and painted.
Figure 14. While working on the shack, we had some good rains, and the Pholela river started to flow quite strongly.

I finally have the ceiling finished, with access door to the rather shallow loft area. The firewall between the radio room and the generator room has been restored; I removed the old plaster, filled remaining gaps between bricks with a strong plaster mixture, liberally coated the wall with bonding liquid and topped that with several layers of good paint. 

In South Africa, the 220 V, 50 Hz house wiring must be installed according to local wiring regulations to ensure that the electrical installation is safe. This is covered in SANS10142-1, The wiring of premises - Part 1: Low-voltage installations. One should check for updates, as these are amended from time to time. I still have to do the plugs, but at least there are lights now. As many of the radio sets use 115 V, several separate 230 V to 115 V step-down isolation transformers will be installed, these all need their own isolation switches which will remove both live and neutral from the input and the output stages. 

For a radio shack, where there will be transmitters operating, one has to go a bit beyond these regulations to ensure there is minimal transmitted RF coupling back into the AC circuits. In addition, as there are sensitive radio receivers being used, one must make sure that the main AC line feeding the radio shack does not carry RF generated by some other source (switch mode power supplies, many digital devices etc.) connected to the line. Also, the source of the main AC could be contaminated with RF, this is especially valid for inverter generated AC. Therefore careful measurements should be made to locate the sources of the RF and measures should then be adopted to attenuate the RF as much as possible. 

This is not an easy task and each installation will have its own unique problems and solutions. Fortunately there are many good single phase block filters available rated at different currents and levels of suppression (normally single or two stage filters) that can be used at different points in the wiring. One must also ensure that the grounding of the electrical installation is very good, and normally this requires the installation of several grounding rods and proper bonding of all metal throughout the structure. In a radio shack that is mostly made of wood, one remains with water and gas pipes and the electrical system's ground/earth mainly that should be bonded. All radio and test equipment should have a proper earth connection, this can be accomplished with a dedicated earth rail located behind the equipment to which the metal chassis of the receivers and transmitters can be bonded. 

One should also very carefully consider what to do about lightning protection. Long AC lines are very prone to carry inductive spikes and although lightning and surge protection can be built into the electrical distribution board (e.g. using a combination Class 1 and Class 2 surge arrester with replaceable modules for single phase), this only provides limited protection and it is far better to have additional measures in place such as to totally remove the AC line from the radio equipment, e.g. by unplugging the equipment and removing the antenna feed lines from the transmitters or receivers and grounding them. A direct strike is of course another problem, and here the only recourse in reality is to hope for the best.

Radio shack update August 2019

Figure 15. The four TCS radio transmitter/receiver sets stacked in temporary configuration, in the same set-up as the sets were in Switzerland. The top right-hand set belonged to Aubrey Wynne, ex ZS5CN (SK). According to what I was told, he had some influence in the establishment of the WW2 radio station in Switzerland. From my notes, the operators used a packing crate for the bottom wooden box section. I found a similar packing crate and removed the steel carrying handles on what is now the top and bottom sections. It still needs to be painted, as apparently, their box was a light grey.

I moved to the farm permanently on the 23rd of June 2019. In South Africa, being in the Southern Hemisphere it is winter in June of course, and I was fully occupied in building stables for our four horses, so had very little time to work on the radio shack. The winter was not very cold; the minimum temperature I measured was -6 degrees Celsius. We had no snow either, not even on the Drakensberg. I suppose it was too dry. 

Anyway, by the 31st of August, amidst building horse stables, I had power in the shack, lights in the ceiling, new locks on the doors, and the four TCS radio transmitter/receiver sets arranged as they were in the station at Luven. I still have to paint the old packing crate that houses the two bottom sets. The crate sits on top of a steel table; this has been painted light grey. The TCS power supplies will be located on the floor below the table. Each TCS radio has its own control box and antenna loading coil. 

Radio shack update October 2019

Figure 16. Collins Radio equipment located in the reproduction of the Luven secret radio station. The equipment is fully functional and an absolute pleasure to use. I have not included any linear amplifiers. I expect that the Luven operators had a second set-up in the small workshop room, as the notes mention a 30S-1 linear and 30L-1 linears. They used the standard Collins fist microphone (MM2) as well as Electrovoice and Astatic D104's. 

As per the radio station layout based on the sketches from the Luven station, I have installed Collins S-Line and KWM-2A equipment. This is roughly what the original set-up must have looked like. There were other Collins equipment as well, but as space was quite limited in the original radio shack (and in the reproduction shack), I expect that some equipment was either stored or used in some of the outstations. 

On the top shelve I have placed a 32S-1 and 75S-1 transmitter/receiver pair (manufactured 1959), flanked by a 516F-2 AC power supply and 312B-4 station control. The 312B-3 speaker located on top of the station control is connected to the 75S-3 receiver 3 levels down (I would not normally stack any S-line equipment, but the speaker box is very light). On the second rack level we have from left to right, 516F-2 PS, 32S-3 transmitter, 75S-3C receiver and 312B-4. This row of equipment will also be used for CW. The transmitters located on the other rows are for SSB only. The bottom row contains two KWM-2A transceivers, one which is linked to a 312B-5 remote VFO, and to the right the 75S-3 receiver. The desk is a grey metal desk manufactured in the USA during the late 1950's.

Radio shack update November 2019

Figure 17. A beautiful rainbow appeared in the eastern sky on Friday afternoon the 14th of November. It had been raining intermittently since the 10th, with a huge thunderstorm on Wednesday accompanied by gale strong winds. So, the earth is soaked and the grass is growing. 

We finally had rain in November. The rain was late this year, so the paddocks were not ready for the horses and we had to keep them on grass bales for longer than we had hoped to. The small black horse is a dog...the dog (Maya) loves the horses, especially the Quarter horse, a chestnut gelding (Apache), in the forefront. Apache will be four years old on 16 November 2019.

Work on the radio shack was limited to removal of the Lister TR3 generator. There is a massive concrete plinth on which it was bolted down that I have to remove now. I bought a big sledge hammer, and will work away at this plinth before I can start renovating this room. Some time was spent on restoring the DWS MK214D transmitter. 

Radio Shack Update January 2020

Figure 18. The Pholela river flows strongly after some good rains (January 2020). 

We counted 302 mm of rain up to 19 January. Here in KwaZulu-Natal, South Africa, we have summer rainfall, with occasional rains or even snow in the winter. However the 2019 winter was dry, no snow and no rain. Towards the end of November 2019, the river was very low and the veld very dry, so we are all very pleased with the rains we had in December/January. The Pholela river is now flowing strongly, and most importantly, the veld is green and the grass is doing well. 

Very little radio shack activity took place since my last update. I painted and completed the construction of the packing crate that will be used to house the TCS radios. It really does look very similar to the one that was used at the Luven radio station. These can now be moved into their final positions and the cable and power supplies can be installed. I did some more work on the DWS MK214D transmitter and the DWS MK219A transmitter/receiver. 

I also completed repairs and construction to the roof section of the main house that will carry the solar panel installation. Sixteen 255 W solar panels will be installed on this section of the roof. These panels will be divided into groups of four (two sets of two in series, and these in parallel). The 4 groups will feed into a combiner, which in turn will feed a 4 kW (48 V) inverter. I still have to build the combiner. This will contain separate fuses and switches for each DC line, ground fault interrupt and surge protection. Each group will have an analogue ampere meter in the combiner box to allow monitoring of their performance. Power will be fed to the radio shack via an armoured underground cable.  

Radio Shack Update April 2020

Figure 19. Apache in training. We have been on short outrides without any "incidents", so I am very pleased with his progress.

We have had a very busy couple of months since my last update in January. The horses take up much time as they have to be trained, fed, led to paddocks, and of course we have to ride them! Apache (4 years old) is a Quarter horse, and as he is quite young and full of energy, he has to be lunged for about 20 minutes before being ridden. He has been on short outrides apart from his sessions in the arena, and is a pleasure to ride.

Figure 20. The four TCS transmitter/receiver sets as configured at the Luven radio station. I am following the original layout very carefully. The top left-hand set belonged to Aubrey Wynne, ex ZS5CN (SK).
Figure 21. Our driveway towards the house, Ranja (German Shepherd) glancing back to make sure her face is in the photo! Autumn is upon us and daily temperatures have dropped to below 20 deg C.
Figure 22. Diplomatic Wireless Service MK214D transmitter pared with an Eddystone EA12 receiver. The Collins 310B-1 located on top of the MK214D can be used as driver, or one can switch to crystal control of the MK214D.

Some progress was made with the installation of the four Collins Radio TCS transmitter/receiver sets (Figure 20). Cotton covered wire and coax were used to connect the ground links and transmitter RF output. The antenna links between the transmitters and receivers are made up of thin section solid copper rod. I installed a 17 ft whip antenna attached to the barge board of the radio shack. The four sets will be switched via an antenna switch to either the whip or a dipole antenna. The loading coils will be used to facilitate matching a specific transmitter's impedance to that of the whip antenna. A small Transmatch (ATU) will be used when tuning the transmitters into dipoles or end-fed wire antennas. This antenna tuning unit uses a TCS roller inductor as loading coil, two variable capacitors and a rotary switch that progressively adds/reduces capacitance to the circuit. I will add the circuit and some photos of this TCS ATU at some stage. As I have been unable to find information on this particular ATU, it seems likely that it was purposely built at the Luven station to be used with the TCS sets.

As can be seen in Figure 21, autumn colours have started to show and with the drop in daily temperatures from early 30's to early 20's and below, we can feel the bite of winter air appearing. I have started chopping and cutting wood for the winter, Eucalyptus (Bluegum) and Black Wattle. These are invasive and I do my bit to aid in their eradication and control. 

The DWS MK214D transmitter  was paired up with the Eddystone EA12 receiver (Figure 22). One can now switch between transmit or receive using the receiver's STANDBY switch and mute circuitry. The mute level has been set so that one can use the EA12 to monitor either AM or CW transmissions. The Collins 310B-1 can be used as external driver or the MK214D can be crystal controlled. Output on AM is 400 watts PEP and 600 watts on CW. A small external tube amplifier is used to drive the modulator stage of the MK214D, this is set to an appropriate output level in conjunction with the Piccolo Modulation Depth setting of the transmitter. I still need to do some on the air tests, but local tests into a dummy load revealed a pure CW tone and clear modulation. In order to do the tests I had to connect the radio shack to en external generator as my solar system cannot at this stage power the larger equipment. 

The arrangement as seen in Figure 22 is exactly the original arrangement at the Luven Stay Behind station.

More information on the TCS transmitter and receiver pair can be seen at Collins Radio TCS  and additional information about the MK214D can be seen at DWS MK214D.


Radio shack update July 2020

Figure 23. The radio shack interior facing the Collins S-line equipment. All of the S-line equipment is now fully operational and have been used for contacts on SSB; only good reports have been received. This is the same layout as the original Luven station, even the clock is at the same location on the half-log wall.
Figure 24. Facing south, AR88D, SX28 and R206 interception receivers; ITG200 AM transmitter, Collins Radio KWS-1 and 75A-4 pairs, DWS MK119A transmitter/receiver. A 1940 Collins Radio TCH transmitter/receiver can be seen on the far left.
Figure 25. Eddystone receivers, DWS MK214D and TCS sets. On the floor below the TCS sets, one can see a backpack used by some of the Luven operators when doing field work during the 1970's. The backpack contains a RACAL HF SSB transceiver (Syncal 30, TRA. 931). 

Time flies when you are busy, and so many other things had to be done on the farm during the last months, that only a fraction of my time could be spent on the replica radio station. Nevertheless, some progress was made, which I present here in photo format. I have tried to keep to the original Luven radio station layout as close as possible, using some sketches and photographs. Not all of the equipment is operational at this stage, as they were in storage for long periods, some for many years. I will have to repair and restore these as time permits. During July I made my first CW contacts using the DWS MK214D and the MK119A. These two radio sets are now fully operational. One of the Collins Radio KWS-1 transmitters have been used quite frequently with good signal and audio reports. The other KWS-1 has a low drive problem and an intermittent VFO, which I have to sort out. The Collins Radio S-line set-up is fully operational and a pleasure to operate. 

There are more S-line radios packed in the shed, these will have to be installed in the room next door. I have yet to find the exact layout as the operators at the Luven station had in the room next door (old generator room), but I expect it will surface at some time.

The Standard Electric ITG200 still requires to be connected and set up. This is an AM only HF radio transmitter dating from WW2. 

I have installed four 100 A/Hr 12 volt batteries to enable operation of radio equipment that requires 12 V. These include the Collins Radio TCH set (fully operational) and an ITT Mackay MSR8000A. The radio room receives 220 volt, 50 Hz power from the main power installation located at the house. This power station consists of a 4 kW solar panel installation, a 4 kW Victron inverter, and a 410 A/Hr 48 V battery bank (eight Trojan Solar SAGM205's).

At some point I need to wire up a 115 V 60 Hz inverter for use with some of the S-line equipment, as well as a 40 kVa, 3 phase inverter which will be able to run the larger transmitters. 

Radio shack update October 2020

Figure 26. Sunset on the 25th of September 2020. View towards the West.
Figure 27. Block burn on neighbouring farm. The river is our border. 
Figure 28. Both typewriters and the wire recorder have their own enclosures.
Figure 29. On the left, Remington  Envoy, centre, Remington Junior and on the right-hand side, Webster Chicago model 78 wire recorder.
Figure 30. The previous owner of this TCS transmitter/receiver set was Aubrey Wynne, ZC5CN. 
Figure 31. The original ZS5CN QSL card of Aubrey Wynne. 
Figure 32. The original card modified to include my details.
Figure 33. TCS transmitter and receiver spares.
Figure 34. Instruction manuals for the TCS radio sets.
Figure 35. The TCS manual of Aubrey Wynne (ZS5CN).
Figure 36. The Royal Astro Optical Industries Co., Ltd. R102 was marketed by Tasco as their Model #20TE. 
Figure 37. The 20TE assembled in the shed. It is complete including two finder telescopes (80 mm and 50 mm), counterweights and other accessories as listed in the Royal Astro Optical Co. brochure.

Well, with the fairly mild winter behind us, we slid into Spring, which rapidly changed into Summer (first thunder clouds can be seen in Figure 26). I have started to work on the old generator room next to the current main radio room. 

The plinth on which the old Lister TR3 was bolted down on is as hard as rock, so its demolition is progressing slowly. I also need to remove the old cement floor as it is a bit diesel soaked and I will have to cast a new floor. 

My physical activities suffered a bit for several weeks as my horse chucked me off and I could hardly walk for a week, never mind swing a large hammer.  Fire breaks and block burns had to be done (Figure 27), fortunately these were completed without a hitch.

I have rummaged through the shed a bit to see what else from the Luven radio station would be next in line for restoration etc. that I would eventually move into the 2nd radio room. As an example, there are some RCA AM/CW transmitters dating from WW2, they will need considerable work before I can install them. Fortunately there are documentation for these as well. 

I even found two old typewriters (see Figs. 28 - 29), dating from the 1930's and early 1940's. I don't know anything about typewriters, but from some information found on the internet, the one is a Remington Junior, a portable typewriter produced from 1933 to 1940. The other is a Remington Envoy Type 2, manufactured from September 1941 to April 1942. It is likely that the Luven operators used these typewriters to keep records, perhaps even to copy Morse code directly to paper. Both typewriters are in very good condition.

An interesting find was an old wire recorder (see Figs. 28 - 29) This is a Webster Chicago model 78, tube complement; 6AR5 6AT6 6AU6 6X4, with a number of wire spools. To my amazement the wire recorder works 100%. There is some CW code on the spools (I only tried one), the speed of the code is at about 16 wpm. It is not in readable text and is made up of a mixture of numerals and alphabetical characters, so must be encoded somehow. It is clearly a recording made from the audio of a radio receiver. This wire recorder is a post WW2 recorder, manufactured in 1948.  

I also found a reel to reel recorder, with a large assortment of tape reels, this is an Akai 1800L unit (manufactured ~ 1968), which has a 4-track stereo recording and playback system, it also has a cartridge section with 8-track stereo recording and playback.  There does not seem to be any 8-track tapes with the unit. The 1800L works perfectly, I tested it with one of the tapes, this tape has some music on it, and the sound quality is superb. 

From some of the notes I have, and from what I was told years ago, the Luven radio station had some of its origins in South Africa. Two of its first operators were from South Africa; they played a major role in setting up the station in Switzerland. Apparently they had some help from Aubrey Wynne, ZS5CN, who was a friend of one of the operators. It would seem that Aubrey Wynne had some military connections, and perhaps this facilitated the establishment of the station in Switzerland. Perhaps he was given the TCS set by the military during the war and had it sent to the Luven station somehow, who knows. 

I doubt that any USA lend-lease equipment such as the TCS sets went directly to Switzerland legally, but possibly via a backdoor, as many people in Switzerland knew they were caught up in WW2, regardless of the official policy of neutrality. Bombs and bullets are not neutral, not ever, whatever your policy is.  

It seems that Aubrey Wynne had two call signs, ZS5J and ZS5CN, which he held from 1946. These call signs were first held by his father (SK 1941). In 1937 his father's call signs were ZU5AK (which became ZS5CN in 1938) and ZS5J, used when operating from Dundee. The ZS5CN call sign was used when operating from Eshowe; these towns are located in Zululand, KwaZulu-Natal. In historic times Zululand was much larger than it is now. Today Zululand is only one of 11 district municipalities of the province of KwaZulu-Natal.  The TCS receiver had a blank example of each QSL card affixed in the framed window which normally contains a card with receiver setting details (see Figure 30). The QSL cards were hidden behind the TCS card. The ZS5CN QSL card can be seen in Figure 31. 

As I now am the owner of the call sign ZS5CN, I scanned and edited the image of the card (see Figure 31) and then updated the details with my own, a nice historical touch!  If I have a QSO with someone using Aubrey Wynne's TCS set, I can send them this card. 

More rummaging amongst the Luven boxes led to the discovery of a Collins Radio 51S-1 receiver. This is an early 1960's general coverage HF receiver, it can receive AM, CW and USB/LSB. The CW mode setting has a 600 Hz narrow bandwidth filter. A very handsome radio I must admit, and matches the other S-Line radios in style. It seems to work perfectly. 

I was quite surprised to find a rather strange object in a box, this being a US Navy wool blanket. This blanket seems to date from WW2. Perhaps this was just chucked into the box when the station was dismantled. There is a box of old clothes as well, I just added some mothballs to it and closed it up again...this box also contained a pair of WW2 flying boots. These boots are made of sheepskin, as the insides are all soft sheep wool. I expect these items have some story to tell.

Another two boxes (one a metal box) contained a large assortment of TCS radio spares; meters, relays, tubes, resistors, capacitors, transformers, etc. plus two typed spare parts lists, one in each box. The spare parts (Figure 33) are mostly packed in white carton boxes, sequentially numbered, some with part numbers.

The spares lists are a bit tatty, but still readable, so I might retype them and add them to the Collins Radio TCS page. The one list mentions numbered boxes, the other numbered cartons. The lists have similarities but are not identical. Another box contains a large number of 1625 tubes, these were used in the modulator and RF stages of the TCS transmitters. 

There are 5 TCS manuals (Figure 34). One of them (Figure 35) has the name of Aubrey Wynne (ZS5CN/ZS5J) on the cover page, with the date 3 July 1947 (3/7/47). This is quite strange in a way, as TCS sets did not appear on the surplus market until much later, in the 1950's, 1960's and even up to the early 1970's. Therefore, it is difficult to believe that equipment of such a high standard and quality as the Collins TCS sets would be available as surplus 3 years after manufacture.

Even so, it would appear that some military radio equipment was released as early as 1947. The SARL Council reported in the August 1947 Radio ZS that they had entered in negotiations with the War Stores Disposal Board since early 1946; that a satisfactory arrangement had not yet been reached, but that they were hoping that a batch of receiver would be released. Of note, is the comment in the same report that "a very large quantity of useful radio equipment has been put up for tender by the Board and your Council has been informed that much of this has been acquired by amateurs at bargain prices". The December issue of Radio ZS contains an article by ZS6EU in which it is described how to add an automatic noise limiter to the TCS receiver. This does clear the issue a bit, as the ZS5CN TCS set could have been obtained in July as part of the War Stores Disposal Board release by tender in mid 1947.

Perhaps ZS5CN visited the Luven site?  Or did he have the TCS set sent to Luven during the war (possibly 1944) and had kept a TCS manual which he wrote his name and the date at a later (3 yrs later) stage? Who knows what really happened.  Normally one would write your name and date in or on a book at the time of reception of the book.  If he received the TCS equipment and manual in July 1947, it must have been directly from the military (through a tender or otherwise); does this mean that this set only went to Luven in 1947 and was not there during the last 2 years of the war? This is the most likely explanation I would think.  My Luven station notes however state that there were four TCS sets used during the war and afterwards. Maybe I will find the answer at a later stage.

The ZS5CN QSL card dates from 1947, as the South African Radio Relay League (SARRL) dropped the "Relay" from its name 1n 1947, to become the South African Radio League (SARL).  

It would seem reasonable then to assume that the TCS set was obtained by ZS5CN on 3 July 1947, directly from the Union Defence Force (UDF), and that he dated and wrote his name and call sign on the front cover on the same day. The ZS5J call sign was not written down at the same time it seems, as the ink seems to be slightly different. It was likely added afterwards. Anyway, according to my notes and the Luven station story, the TCS set was sent to Switzerland and ended up at the Luven "Stay Behind"  station. The TCS set found its way back to South Africa much later, probably 1975 when the station was dismantled, still in good condition, complete with its original manual. During my search for the Luven station equipment, based on what I was told years ago by T McMenemy (ZS2TM), I found the Zs5CN TCS set,  and bought it from his family as he was SK by then. These details are a bit blurry as that was a long time ago. 

It could be that one of the four WW2 TCS sets were damaged and were replaced by the ZS5CN set at a later stage. Maybe that explains why there are 5 TCS manuals. Anyway, be it as it may, the ZS5CN/ZS5J TCS set is now safe in its reproduction WW2/Cold War stay-behind station. 

As it is still October, and I had a bit more time to scratch around in the shed, I unpacked and assembled a  Tasco 4¼-inch  (108 mm) f/14.8 refractor telescope. This telescope (described as a top-of-the-line achromatic refractor, according to sources on the internet) was made in Japan by Royal Astro Optical Industries Co., Ltd. as their Model R-102 (Figure 36). Its objective lens was supplied by Horiguchi Optical Company. 

The telescope (Figure 37) was manufactured in the 1960's -1970's, and was marketed by Tasco as their model #20TE. This telescope is no relation of modern (low quality in comparison) Tasco telescopes.  It has all its accessories (Figures 38 - 39) as listed in the Royal Astro Optical Co, brochure. It even has the Sun projection screen (not included in the photos).

I also unpacked a slightly larger telescope, which has a 5 inch objective, and very heavy mount; the mount has the engraving "Made in West Germany". So this telescope was constructed sometime during the Cold War. According to the set of construction notes the 5 inch achromatic objective was made by Dieter Lichtenknecker (* 12. März 1933; † 26 August 1990). Whatever did the Luven radio station do with refractor telescopes? Your guess is as good as mine, but they probably tracked satellites as a guess, although a refractor with sidereal drive is probably not the ideal instrument for satellite tracking. To what purpose I would not know. There are a couple of boxes, which includes telescope engineering drawings, printed C source code, and bits of hardware. Maybe more information are to be found in the folders in these boxes.

These telescopes seems to be a project on its own, so I will dedicate a separate page to them. However, as a primer, and hopefully as some reader might send me additional information, I am adding some photos of the Tasco #20TE. 

Figure 38. Tasco 20TE eyepieces; a sliding lid closes the box and makes it dust proof.
Figure 39. Filters, star and Sun diagonals and erecting prism.

Radio shack update November 2020

Figure 40. Clapp Eastham telegraph key on marble base.
Figure 41. German manufactured telegraph key used by the Luven station. 

I cannot believe that it is already November, but as summer is here in its full glory, and we have already had our first dinner containing mushrooms collected in the garden (Boletus Edulis), I have to admit, it is November. This mushroom is known as cep in France and Steinpilz in Germany. We were fortunate to have had some good rainfalls early in summer, so the veld is green and the river is flowing strongly. Anyway, for those few of you who are following these pages, I have been working on the book about the Luven station, but it is still far from being complete. It is progressing though, this I can report without hesitation. As you may appreciate, it is not an easy task to reconstruct the events surrounding the Luven station in book form. 

So, I found the hand-drawn schematic of the little transmitter that was built in Luvis, before it was named Luven, and it seemed to have been built during November 1939. The notes concerning the transmitter contains various alternative versions, some more complicated than others, one even had a superheterodyne receiver connected to the transmitter in a transmitter/receiver combination. Another version contains a modulator stage using a 6V6. In the end however, it seemed that a crystal oscillator using a 6V6 tube, followed by an 807 for the RF amplifier was used for the transmitter. This was a CW only transmitter. It was built into a wooden box as the operators had no access to metal or metal working tools initially. One sketch clearly illustrates a transmitter/receiver unit, utilizing two National Precision Velvet Vernier Type N Dials. It also contains an RF current ammeter and milliamp meter. It is quite possible that the Luven station built the basic 6V6/807 crystal controlled transmitter first, and then afterwards built a complete low power transmitter/receiver combination. So, from what I can gather, by November 1939 the station had an RM69 receiver and their own constructed, low power crystal controlled transmitter. There is a box full of crystals, some with frequencies inside the ham bands but also some that are outside the ham bands. It seems that the transmitter could cover 2 - 8 Mc/s only.

There are notes about the CW keys that were used, in particular mention is made of a Clapp Eastham key on a marble base (Figure 40), as well as of another key, which was a German made key (Figure 41), marked Ta.P. enclosed in a circle[1]. Above the circle is a lightning bolt logo. On the Bakelite lid (which could open to expose and give access to the innards) it is marked - Vor dem offnen stecker herausziehen. I found both these keys in a box, which also contained a number of old headphones, these have brand names such as Brandes, Trimm and Siemens.  



[1] Ta.P is the abbreviation for Taste Paula (Key Paula)


Radio shack update January 2021

Figure 42. We have had early rains this rain season. During December 2020 and the first week in January 2021 we had many days of mist and light rain.  

Figure 43. Front view of the SB-34.

Figure 44. Rear view of the SB-34. The VOX and xtal calibrator units were optional add-ons.

Figure 45. Top view of the SB-34. The Collins mechanical filter can be seen in the top right of the unit.

December 2020 flew by and there was basically no time for any radio or replica radio hut activities; so I will do some January 2021 updates, hopefully this will force me into action. We had a fairly wet and misty December, and similar weather into January.

In the first week of January, I scratched around in the shed a bit on one rainy day, and found a SideBand Engineers Model 34, the SBE "SB-34" transceiver, hiding in a box, complete with original microphone.  

Frequency coverage: 

This transceiver was manufactured in 1966, and this particular unit is equipped with the optional VOX and crystal calibrator. The IF filter is a Collins mechanical filter (2.1 kHz).  What I found interesting, is that the VFO reduction drive is a Jackson Bros. type, similar to what was used in the DWS MK119A transmitter/receiver. Within about a 3/4 turn the dial reduction is high, if you pass that point the reduction is low, allowing quick frequency change. I will need to spend a bit of time on the SBE-34, the power supply capacitors are definitely dry as there is a fair amount of hum on the audio, and the set requires alignment. A quick test on the 40 m band brought in a 59+ report, and comments of excellent audio quality.

Output currently is about 40 watts, according to the manual, 60 watts should be possible. The SB-34 is transistorized except for the driver and two final tubes. There are no notes on the use of this transceiver by the Luven station operators. So it is a bit of a dark horse at this time. Perhaps some information will surface at some point. It could be used on either 115 volt AC or 12 volt DC. I have not seen the Sb-34 in any of the radio hut photos, so I doubt that it was used inside the hut. These transceivers were designed to be used as mobile units as well, so perhaps it was used inside a vehicle, or even just as a portable due to the fact that it could operate off 12 volts. The only reference I have found in the Luven notes to a vehicle, was that at the end of 1939, when the station was established, a Saurer truck was used by the three initial operators. No mention of any other vehicles were made. The SB-34 only arrived on the market in 1966, so it is more likely that they used the transceiver as a portable unit, at an outstation. There is mention in the notes of outstations, some which seemed to have been nothing more than a tent pitched in the mountains, others were in small wooden huts. As portable units, my notes mentions late 1950's Morrow Radio (see  Radio equipment) transmitters and receivers (the MBR-5 / MB-560 pair and the MB-6 / MB-565 pair) as well as the Ten-Tec Argonaut 509 which was introduced about 1973 and the Ten-Tec Triton II introduced in 1976. 

The VFO of the SB-34 is amazingly stable. There is no noticeable drift, even from switch-on. I will have to measure the actual drift as it seems too good to be true.

Today (15 January) we had a large thunder storm, and I was caught outside so took shelter in the shed. A further scratch around in the shed amongst the Luven station boxes led to an interesting find, a Collins Radio, winged emblem, wind direction and wind speed indicator, complete with wind-vane and anemometer (Figure 46 and 47). The Luven radio station probably logged the weather, although I have not found such a log amongst the books and documents. The wind speed and direction indicators were rack mounted as they are mounted in a 19" rack panel. The wind direction dial and anemometer use a selsyn (synchro) each. The anemometer must have a small dc generator to feed the display. 

Figure 46. Collins Radio wind direction and speed indicators. The wing emblem dates the unit late 1950's or early 1960's.

Figure 47. Collins Radio anemometer and wind direction vane.

Radio shack update February 2021

Figure 48. DASD QTI Net 80 m band channels.

Figure 49. Collins S-Line set-up at the Luven station, the 32S-3 transmitter was paired with a 73S-3C receiver. The CW key was manufactured by Elliot Brothers. This photo is dated 1967.

Figure 50. Elliot Brothers CW key.

Figure 51. Ten-Tec Triton II. 

Figure 52. The Argonaut 505 and Model 210 power supply. 

My first introduction to the Argonaut was in 1975. Roy Altenkirch, ZS2HJ stayed in Galway Rd, a couple of streets away from our house. His radio shack was in his garage. Many years later, I often stayed in his old house as it had been changed to a Bed and Breakfast establishment. OM Roy had an Argonaut, and some dipole antennas. I was still in school, and used to visit him late afternoons or Saturdays. Judging from the QSL cards against the wall, that Argonaut talked to the world. 

Figure 53. The Ten-Tec Mod 546 Series B (Omni-D). 

Figure 54. National Radio HRO-MX.

Figure 55. Bendix Radio Type TA-12B aircraft transmitter. 

I have decided to show some odd bits and pieces of some of the old Luven station documents and books that I have found in the shed. Some of it may be of interest, some may just be what it is. Figure 48 displays a document that has a list of channels used by German radio amateurs during WW2. I tried to figure out the details of this document. Maybe the reader has a better idea what it means, but what I think is the following; 

Figure 49 is a photo of the S-Line set-up used at the Luven station. The photo has a pencil date of 1967 at the rear. The Collins pair made up of a 32S-3 transmitter and 75S-3C receiver was used in SSB and CW mode.  The CW key was manufactured by Elliot Brothers of London circa 1920. I found the key (Fig. 50) in a box with other bits and pieces and will connect it and use it with the original transmitter and receiver. These were standard British GPO style keys. Perhaps someone else has more information on this key, please forward this information to me by e-mail. From some of the drawings I have, this S-Line was connected to a Collins 30S-1 linear amplifier. I have no idea how this key found its way to Luven. 

Nearly out of the photo, in the bottom left-hand corner, one can see a pair of binoculars. It is a bit difficult to identify, but it appears to be a Zeiss, probably ex-military 7x30, dating from  the 1930's. I have not found this pair of binoculars in the Luven station boxes yet, if indeed it is there.

Whilst scratching around in the shed one afternoon during a thunderstorm (we get these quite often in the summer), I discovered a box with some Ten-Tec equipment. These are all fairly old, dating from the early 1970's. I will add some photos here (Fig. 51 is a start). There is an Argonaut (Mod 505) (Fig.52), three Argonaut 509's, a Triton II (Mod 520) and a Triton IV (Mod 540), as well as a Mod 546 Series B. There are two M0d 405 linear amplifiers, some power supplies (Mod 252, two Mod 210), two calibrators Mod 206, Mod  244 digital readout and a Mod 243 VFO. Finally, there is a box of spare parts.

I know that the Luven station had some outstations, the first which was established in France at the end of June 1940, about a week after the armistice of 22 June 1940 between France and Germany was signed. Other outstations were also established during WW2 and after, sometimes nothing more than a tent in the mountains, often temporary and portable. As many of these Ten-Tec transceivers  (Mod 505 and 509) were low power (about 3 watts output) and they were all relatively small, and could run off a 12 V battery, I expect they were used in outstations somewhere in Switzerland, or in neighbouring countries, most likely as part of a Cold War project during the early to mid-1970's. I used one of the Argonaut 509's in a quick test, and I must admit, there is something mystic about these little rigs. It reminded me a bit of home baked bread, and cheese, simple, good stuff, and real. I will probably do some cleaning up, some repairs etc. but these will make a nice set-up, and most likely I can use them as small portables for camping in the mountains.

Today, February 16, I tested the Argonaut on SSB and made a QSO with OM Kobus, ZS1K, who was mobile near Beaufort West on his way to Rietbron (Rietbron means reed fountain or reed source), which is 85 km south-east of Beaufort West. He gave me a good report, so all seems well with the little Argonaut. The slide dial needs some re-setting, but all else seems fine.

I worked on the Omni-D Model 546 Series B  today (17 Feb), amidst setting up new fencing for the horses in a temporary paddock. I made a CW QSO with OM Tom ZS6OMT in Potchefstroom and with ZS1SA OM Rob in Cape Town, all on the 40 m band. Then I chatted with V51WW OM Wynand in the north of Namibia on the 20 m band on SSB. The Mod 546 works fine, smooth CW QSK, 100 watts output, nice bandwidth filters (it has the standard 2.4 kHz SSB and the optional 0.5 kHz CW and 1.8 kHz SSB filters installed) and variable notch filter. I need to work a bit on this transceiver, the DC power leads must be replaced and some other small cosmetic repairs need to be done. It is a nice rig however, and fun to use.

Today the 25th of February, I tested the DWS MK214D transmitter paired with the Eddystone EA12 receiver using CW. The CW key used was the Admiralty Type D. I have a crystal for 7002.6 MHz, so that was the frequency used and contact was made with OM Eddie, ZS6BNE. Eddie's transmitter had a 5 watt power output and the MK214D was set to low power, which effectively reduces screen voltage on the 813's and output was 200 watts. Setting the screen voltage to "high" gives 400 watts, and setting it to CW gives 500 watts, without trying hard. Previously I had noticed a slight drift in frequency when keying the transmitter, and I fixed this problem; OM Eddie reported no problems and gave the MK214D a 599 RST report, so I am happy. With his 5 watts he was 599 at my location as well. The MK214 was manufactured in the early 1960's and the Eddystone EA12 in 1966.

Well, the end of February is in sight, we have had some rains this week, but need more before the winter moves in on us. I am on page 177 of "The Key Messenger" book. It is quite an interesting story, the most difficult is to piece together the events that occurred at the Luven station in some chronological sequence that makes sense. Sometimes notes and photos do not have dates, and I have only one diary to work from; this is written in longhand, some of it in German, so it can be quite tedious to decipher the text. Whilst looking for two books that were supposed to be used to encode messages from the Luven radio station (they never used one-time pads or an encryption machine)  in the shed amongst the Luven boxes, I happened upon a nice example of the HRO Senior receiver. This is an early 1942 model, the HRO-MX (Figure 54), complete with a wooden tray containing plug-in coil units. The HRO receivers were used quite extensively by the British in WW2 as interception receivers. It needs a bit of a clean-up, but is complete and original.

On the last day of February, Sunday the 28th, I found myself digging in the shed once more (in the meantime I have found the two books the Luven operators used to encode some of their signals) and discovered a large box with a Bendix Radio Type TA-12B aircraft transmitter, some sort of junction box, an MN26 receiver, direction finding loop antenna, control cables, remote control box with frequency readout and a compass type control for the direction finding antenna. The box even contains an original manual for the TA12-B and MN26 set-up, a modulator  and an MT-11B telegraph key. There is a note inside the box, which reads "Vom Aufklärungsflugzeug" or at least that is what it looks like. How this equipment got into Switzerland is a mystery.


Radio shack update March 2021

The Collins Radio TCS sets as at March 2021. The bottom right-hand TCS 10 set is used in CW mode on the 80-m band and is a lot of fun to use. 

Figure 56. Collins Radio TCS 10 transmitter and receiver set. 

Figure 57. State of the 2nd radio room as at the beginning of March 2021. 

Figure 58. Plaster and paper ceiling (plasterboard) removed. The roof beams are in good condition.

March 2021, the evenings and mornings are already cooler and I have cut more wood for the winter. Fortunately I can cut down trees that are exotic species such as Black Wattle (Acacia mearnsi)and Bluegum (Eucalyptus Saligna), both of which are invasive species in South Africa. 

On Thursday night the 4th of March at 20H00 SAST I called CQ using CW on the 80 m band, 3.550 MHz, using the TCS 10 set (Fig. 56). More details on the TCS radios can be seen at Collins Radio TCS. The antenna used was an 18 ft whip, similar to what the TCS sets often used as antennas during WW2. I had a quick QSO with OM Jan Holtzhausen (ZS5HJ), whose QTH is about 200 km distant. The report from ZS5HJ was good, so I was pleased that the old TCS 10 was still emitting a pure and stable CW signal. There was an interfering heterodyne clearly audible close to 3.550 MHz, which I found a bit irritating, but I could copy OM Jan clearly. As some of you may know, keying the transmitter is a noisy affair as the tx/rx relay clatters quite loudly when keying (there is no grid-block keying here), it also produces a bit of noise in the receiver. The emitted CW signal however is pure, with no audible chirp or frequency shifts. What I normally do when using a TCS set on CW is to monitor the keying on a monitor receiver, and to switch off the speaker of the remote control box when transmitting. Then keying is easy, and the clack-clack of the relay becomes a bit masked by the CW tones from the monitor receiver. In their standard configuration, with no modifications, these sets are an absolute pleasure to use. There is no need to modify these radios. They have a high fun factor, and in my viewpoint, rank very high in my list of real radios.

I have started to tackle the 2nd radio room (Fig. 57). The plinth is as hard (or harder I think) as rock and only dynamite will remove it. So I have to modify it and use it as an integral part of the renovations of the room. The TR3 Lister diesel engine and generator set has been removed. I will pull down the ceiling and replace it. The floor will be screeded with a cement sand screed. I will remove the DB boxes on the wall, as I have already installed a modern and compliant distribution board in the other room. The portable generators will be moved.  

On Sunday the 7th we spent the morning exercising horses and going for a short out ride. In the afternoon I found a couple of minutes to remove the old ceiling which was in a bad shape. I still have to remove the nails and clean up the rafters (Fig. 58) a bit, but they are in good shape. I will also install the power lines for a ceiling light. 

Radio shack update April 2021

Figure 59. Collins Radio 32V-1 transmitter (bottom), 75A-4 receiver (centre). These are a pleasure to use on either AM or CW.  The receiver at the top is an Eddystone Type 358 (358X), (Admiralty Type B34).

March rushed by and April surprised me. The ceiling and ceiling light in the one room of the radio shack have been installed. The ceiling still needs to be painted.  On Saturday the 10th of April I used the Collins Radio 32V-1 transmitter and 75A-1 receiver (Figure 59) to hand out some points to a local CW QRP competition on the 40 m band.  These Collins radios were manufactured in 1947. There is no full break-in on CW as a switch must be toggled to switch the transmitter to transmit and to mute the receiver. Permeability tuned oscillators are used in both the receiver and transmitter, so they are both stable enough for AM and CW. The receiver has a crystal filter with five settings and phasing control as well, this provides for some degree of additional selectivity. I use these with a straight German made key, dating from the 1930's. 

I have started to cast a layer of screed on the existing cement floor.  This layer will be about 10 mm thick. I first tested a 1 m square block in a corner, as I wanted to be sure that the screed would be tough and hard enough. It seems to be, so I will complete the floor with the product I tested.  On the 26th I had a small section of floor left to cast. I found a bunch of cedar planks that I will use to cover the plinth; but first I will give it a layer of screed, followed by a bonding liquid to seal the screed, and then cedar wood planking. 

Well, I did do some  work on the shack during April, so to finish off this short update, the floor has been screeded, sealed and painted. The logs that make up the east, west and southern walls were brushed clean, the northern (brick) wall was sealed and painted. The old ceiling was removed and a new ceiling installed and painted, and a light and switch was installed.

Very little radio work was done, the bands were poor and we were very busy with other things here on the farm.

Radio shack update May 2021

Figure 60. Autumn colours. In the early mornings, one can sometimes see a small buck buck (Grey Duiker) browsing amongst the leaves.

Figure 61. Wooden table under construction. 

Figure 62. Morse key by A Franks Ltd. A bit worse for wear, but works very well.

Figure 64. Completed radio room table. The 3 kVA sinewave inverter will be installed in the left-hand corner.

May 2021, winter is upon us and although I had cut down some trees for firewood my wife assures me it is not enough. Autumn colours (Fig. 60) are everywhere and the house is surrounded by a carpet of brown leaves.

I have started to build the table in the radio room, it is bench-height, so that one can also stand and work, which is sometimes easier. I will add two bookcases, one to the left and one to the right of the door; there is just enough space for them to fit snugly. Compared to Figs. 57 and 58, much progress has been made in the radio room. 

Anyway, as per habit of mine, one cold afternoon I spent some time rummaging in the shed amongst the Luven radio station bits and pieces and found two Morse keys.  The key in Fig.62 was manufactured by A. Franks Ltd. of Manchester. It is a three terminal make/break key, this particular one is missing the centre terminal. Its front contact is located below the the knob, an unusual feature, as the front contact is normally located more towards the pivot point. A brass screw on the arm at the pivot point is also missing. There is no date or manufacturer name on the key, but it is most probably from the 1920's.

Figure 63. Glass top Morse Key.

The glass top Morse key as seen in Fig. 63 was manufactured between 1910 - 1920. This Morse key is a five  terminal Double Current G. P. O (British Post Office) key; there is no specified manufacturer or date on the key. The switch was used to trigger a relay for receiving signals (receive) or to transmit (send).

By the end of May, as can be seen in Fig.64, the table had been completed. I dug an old sine wave inverter out of the shed, it seems to have been manufactured in 1985, and its origin is a bit dubious, but it has Siemens transformers inside and is very well built. A note of the Luven radio station mentions this 3 kVA inverter, as well as a 40 kVA, 3-phase inverter. The larger inverter is still in the shed and will be a future project, it apparently was used to run the large Granger Associates SSB transmitters.  I had to do a little bit of work on the 3 kVa inverter. It is a 48 V DC to 220 V, 50 Hz AC inverter and when connected to 230 V AC fed from the house tended to go into over voltage mode, due to the higher (10 V) voltage fed to its AC input. This was sorted out after I installed two 5 V, 20 A, transformers in series with the mains input as bucking transformers; the old inverter is now quite happy and functions 100%. Four 105 Ah, 12 V batteries are currently used on the DC side of the inverter. I will add a  switch that will allow the radio shack to either utilize power from the house AC line, or from this 3 kVA inverter. I still need to add a line filter in the inverter's output line to remove some RF generated by the switching circuits. It does radiate far less RF than modern inverters, so I am confident that I will be able to make it "radio friendly". All it's input and output cabling were renewed with wiring of more than adequate capacity.

Radio shack update June 2021

Figure 65. Radio operator using Collins Radio TCS10 transmitter and receiver in CW mode. 

To commemorate D-Day and Operation Overlord on the 6th of June  I set up a 40 m and 80 m band CW sked with the local CW interest group. Conditions were not favourable, but I managed to get 4 contacts on the 40 m and 3 on the 80 m band.  I used a  Collins Radio TCS 10 transmitter and receiver (Fig. 65). The IF of the receiver is a bit wide, so I could simultaneously eavesdrop on a CW station 10 kHz higher...a bit high pitched, but perfectly readable! The TCS transmitter was heard in Mauritius, which is located at a distance of 3000 km from the radio shack.

I started to do some wiring in the adjacent radio room. After two years on the farm I have come to the conclusion that our present power capacity is a bit light for operating tube transmitters and receivers. During daylight we mostly have adequate capacity from the 24 solar panels, however once the sun has set all electrical power must be generated from our battery bank. So, the general idea is to boost capacity a bit by increasing the size of the battery bank at the radio shack, and also to add additional power generating capacity via a wind turbine. We often have wind channeling up the valley early morning while it is still dark, or late afternoon. Through a bit of power switching, I would be able to run the radio shack from either the power system at the main house, or from the inverter and battery bank at the radio shack, or be able to supplement power either towards the radio shack or towards the house depending on where surplus energy is being generated. 

By mid June I now have the inverter installed and wired. I also added a new distribution board. Two book cases have been installed. These contain a variety of interesting books on radio tubes/valves, antennas, many dating from before WW2.  From my Luven radio station notes, as as mentioned in the Introduction, and at Radio equipment, the operators had an RCA ET4335LF (MI-8168-B), which is a low frequency A1 and A3 transmitter. Output is 250 watts (A3) and 350 watts (A1), frequency coverage is 150 to 600 kHz.  

They also had an undocumented ET4335E, where I think the E stood for experimental. I have now dug out the RCA ET4335E transmitter, but it is in bad condition as it seems that it suffered from transformer failure at some stage; the bottom section is covered with a black tar-like substance that must have leaked out of the transformer. It is all in a bit of a mess at this stage, I cannot even see where the tarry substance came from, perhaps the large HT transformer is unharmed. The wiring is also in need of repair/replacement as much of the insulation has become brittle, particularly at the end sections where rubber boots had been used. Some capacitors also seem a bit old and tired, so I think this particular ET4335E will need a rebuild. I will make a link from here to a new page, to document this refurbishment in detail. This page can be found at RCA ET4335E.

Radio shack update July 2021

Figure 66. The radio workshop as at the end of June 2021. 

Figure 67. Transmitter room floor preparation. The floor is essentially on bedrock and has a steel mesh layer. The cement will be 10 cm thick, covered with 1 cm self-levelling screed.

Figure 68. The new cement floor. 

Mid-winter; it has been a very mild winter until date. The lowest temperature we experienced was -5 deg C, we had no snow, except on the Drakensberg about 30 km west from us and on the Bulwer mountain about 5 km to the north. I moved some tools and radio spares to the new radio/workshop room. It is quite small so I need to use the available space efficiently. I repaired a dead Argonaut 505, I traced the problem to one of the audio output transistors, which suffered from a dry joint. 

Work continued on the radio workshop, Fig. 66 records its status as at the end of June 2021. Compared to its status as shown in Fig. 57, there has been much progress even though it took some time. I have since installed venetian blinds at the windows; these are very practical and easy to keep clean.

The Luven radio station had two large Granger Associates Model 272-6 SSB/CW transmitters. More details can be seen at Granger Associates Transmitter 272-6 and related information,  I suspect they were part of the Swiss National Redoubt (Schweizer Reduit) radio network in the late 1960's to perhaps the mid 1980's. Initially these transmitters were housed in a metal shed, but were then moved to a transmitter room attached to the old mountain hut. This was a brick and wood structure. Initially I thought a small observatory complete with run-off roof was located on top of this section, however it seems that the observatory was located some distance away, maybe on a small rise to reduce obstruction by trees.

Unfortunately I have not been able to find a photo of the complete radio station, and except for some early rough sketches, I can only work off some notes I have found. The picture that has emerged in my mind from the information I have, is that the building had an L shape; most of the construction was out of logs. One of the radio operators mentioned a small room, in which he stayed, this room was located underneath the radio room; this must have been a cellar, so the ground must have sloped quite steeply. It had low head-room, and could apparently only house a bed (which he built himself), a small table and one  chair. The Redoubt structure was added to this side of the building, so I reckon it was down-slope, forming the top tip of the L shape. I will not be able to recreate the cellar component, but will try and build the 272-6 transmitter room. The floor preparations can be seen in Fig. 67.

Mid July, and the transmitter room floor has been cast (Fig. 68). It should have been finished already, but other unfortunate events in the country delayed the casting. 

Radio shack update August 2021

Figure 69. Morse key, Admiralty Type D.

How time flies! Amazingly it is August already, day temperatures are up to mid 20's deg C, minimum temperatures are just below freezing, and our sand pear tree is blossoming. We might still have a cold spell, but Spring is in the air.  Very little time was available for radio shack work, but I can report that I dug out another Morse key, it is an Admiralty type D, still in its original wrapping and box  (Figs. 69 and 70).

We had some snow (Fig. 71) on Saturday the 28th of August. A bit late in the winter, so within two days most of the snow had melted, feeding the streams and the Pholela River.  The next day we took a walk in the forest (Fig 72). It was too late in the winter for the snow to last, so in the bright, warm, early spring sunshine, the snow started to melt the next day (Fig. 73).

Figure 70. Type D Morse key with cover removed.

Figure 72. Snow in the forest.

Figure 71. Very late winter snow. I will definitely add a small wood stove in the add-on section. Hopefully it will be ready by next winter.

Figure 73. The radio shack in snow and sunlight.

Radio shack update September 2021

Figure 74. Ten-Tec Argonaut 505, model 405 RF amplifier, frequency calibrator and Argonaut Model 210 power supply.

Figure 75. Military map case. 

Figure 76. Military case, with fountain pen, pencil and opisometer.

Figure 77. WW2 fork and knife. The knife has a Reichsaddler and swastika on the handle.

Last month's update was rather short, so I plan to put in more effort this month.  In the February 2021 update I mentioned the Argonaut 505 and that it would require some alignment. I aligned the radio and also found a Model 405 RF amplifier, calibrator and a Model 210, 1 Ampere power supply in a box. There are still more bits and pieces in the box, but that will have to wait for another day. The Argonaut now works very well, it is easy to set up for CW as well once you know how the transmit offset works. Frequency stability, dial linearity and frequency setting are all very good for such an uncomplicated radio. The amplifier will increase the Argonaut's 2 watt power output to 50 watts. I suppose for the Luven operators, such a low power transceiver was very practical when used in remote outstations. To save battery power, one can even switch off the meter and dial scale bulbs. 

I have paired up the little Argonaut with the Morse key by A Franks Ltd.  (Fig 62). This combination works very well. I tested the Model 405 linear amplifier, which is RF activated. It is necessary to set the delay of the amplifier quite long, otherwise the relays within the amplifier drop out while keying, creating fast QSK, but it will also ruin the relays. So, set to a long time constant, CW is no problem for the little amplifier. The first dit or dah might be cut fractionally, but who cares, the rest of the characters are there in full dress code. The longest, uninterrupted CW contact I had this year to date was with OM Tom, ZS6OMT, who used to be a Navy radio operator before retirement; our current rag-chew record stands at 1 hour 53 minutes. What a lovely person to chat to! Unfortunately band conditions then deteriorated and QSB ended our rag-chew. I have made a silent pact with the little Argonaut that it will be used to better the ZS5CN/ZS6OMT rag-chew record. 

The RCA ET4335E project received some attention this month. I repaired the VFO unit, it had a broken filament choke wire. Once repaired, I tested the stability of the VFO (it uses an 807 tube as oscillator), and found that it is amazingly stable. In a 7 hour test from switch-on, it drifted less than 100 Hz in total at 1.5 MHz. Some photos and more information can be found at RCA ET4335E.

While rummaging through some boxes in the Luven station stash, I found some "artifacts" of the station.  One of the artifacts is a map case (Fig. 75 and Fig. 76), inside the map case was a fork and knife (Fig. 77), (the knife is stamped with Reichsadler and swastika), some maps, an opisometer (made in Switzerland) for determining distances on maps, an old fountain pen and twist action telescopic type pencil as well as some personal documents (Arbeitsbuch etc.).  I will leave out the maps and personal documents here, but we can have a look at the other artifacts. In the box I also found two waterbottles, two mess kits (Fig. 78 and Fig. 79) and a pair of Zeiss binoculars.

Figure 78. Old mess kit and waterbottles.

Figure 79. Old mess kit, additional sections exposed.

Radio shack update October 2021

Figure 78. Forest to the north of the Luven radio shack. 

Book progress

I imagine that one or maybe even more people have wondered when this book that covers the story of the Luven radio station will ever surface. Well, you will have to be patient. I am slowly making new discoveries and am piecing together what transpired at the station and elsewhere. As far as I could figure out, the station was located on top of a hill, about 2 km west from Luven, next to a forest. I found this photo in a box, I assume it is a photo of a path within this forest, it does look like a spruce forest.  

According to the diary of one of the operators,  two of them fled through this forest on skis during the winter of 1939/40 in an attempt to escape from two Gestapo agents. 

Radio shack update February 2022

Figure 79. We have had good rainfalls during January and February. The Pholela River is flowing strongly and the underground water has been restored, so fountains are flowing once more.

The first update for 2022; life has been very busy with all sorts of activities, so the radio shack was neglected a bit. Tom (ZS6OMT) and I improved our rag-chew record to 2 hour 52 minutes during February, and we now have to get across the 3 hour hurdle.  

Radio shack update April 2022

Figure 80. Profiled pine logs that will be used for the radio shack extension.

Figure 81. TBY-8 VHF transmitter-receiver used in WW2. 

Figure 82. Headset and microphone of the TBY-8 radio set.

Figure 84. TBY-8 transmitter/receiver top view of components.

April 2022, the world is in turmoil with war between Ukraine and Russia, and we all wonder where  and how it will end. I have had to spend much of my free time in town working on projects there. These should be completed by the end of April or at least by May. I have been searching for 805 tubes for the ET4335E project, but have only managed to locate one. Other leads have turned out to be dead-ends. Tom ZS6OMT had his 80th birthday on 27 March. I sent him a Bencher paddle key for his birthday, somewhat in advance, but when you get to be 80, you are allowed to open your presents some months prior to your birthday date! We successfully beat our previous rag-chew record on the 40m band, the length of the QSO being 3 hours and 26 minutes, Tom used his new Bencher paddle  and I used my old 1930s German made TAP straight key. With rag-chews, our average speed in words-per-minute is around 18-19 wpm, that is a comfortable speed, yet fast enough to chat about the worlds problems.

I managed to find a number of profiled pine logs for the radio shack extension. With a bit of ingenuity, these should be enough to build the add-on section. As I plan to move the Granger Associates Transmitters (272-6) into this section, the door needs to be a bit larger than a standard size door, specifically in height. There will be a top floor, more like an attic really, where I can read and write in peace.

Some scrounging in the shed led to the discovery of a WW2 TBY-8, I found it in a box, buried underneath an old green parachute. The parachute is full of holes, but the TBY-8 (Fig. 81) is in very good condition, it even has its manual and calibration book. There is also a headset, Morse key and collapsible antenna. There is some reference to a vhf station in my Luven notes; the relay station was located on one of the mountain tops, it was used as a lookout post and the TBY-8 must have been used to contact other stations, including the Luven station. The radio was most probably used as part of the Swiss mountain retreat VHF radio network.

Figure 83. TBY-8 Morse key. The rubber box also contains a transmit/receive switch.

Figure 85. TBY-8 front panel, serial no. 3396.

Figure 86. TBY-8 calibration book.

Radio shack update May 2022

Figure 87. Collins Radio 32V-1 transmitter and 75A-1 receiver pair.

Figure 88. Wireless Set 46 MK II and headset/throat microphone.

Figure 89. Wireless Set No. 38 MK II as found, complete with 60 years of dust, but it will clean up easily.

Figure 90. Transmitter-receiver ZC.1 MK.II. These were designed and built in New Zealand during the latter stages of WW2.

Winter arrived with snow on the Drakensberg and late rains here on the farm. I had much to do in town, some work in Underberg and Himeville.  All of the work I had in Underberg has been completed (except for a small solar power installation) and most of the work in Himeville (~2.5 km from Underberg).  A new horse arrived, Mystical Dancer, but we just call him Mist, which is quite appropriate as here we are often covered in a blanket of mist. He is an Anglo-Arab, his father was a Crabbet Arabian, and his mother a Thoroughbred. Mist is a very sweet horse.

I made some CW contacts during May, and also worked on AM a bit using the Collins 32V1/75A-1 pair (Fig. 87). Using these I attained first place in a local contest organized by the Antique Wireless Association of Southern Africa (AWA). I think there were only 2 logs submitted, so my achievement is but small. These old rigs are fun to use!

Some work was done on the RCA transmitter. These details are captured on the RCA ET4335E page.

I managed to dig out more equipment in the shed, these were all from WW2, a Wireless Set 46 Mk II (WS46 MK.II) complete with antenna, headset and throat microphone. There was also a Wireless Set No. 38 Mk.II (Fig. 89), as well as a New Zealand transmitter/receiver (Fig. 90), the Wireless Set No. ZC.1, MK.II. All of these are old, and have not been switched on/used for at least 60 years, but are quite restorable as they are in original condition. What were these used for by Station L? Inside the canvas carrying bag of the WS46 I found a hand written note, "Batterien sind knapp!"  This was clearly a message to conserve battery life. I did not find any other notes, I did however find an old German map of southern Bavaria. It would seem that the two portable HF sets were used for excursions into Bavaria by at least two members of the Luven radio station. Hopefully I will dig up more information as to where and when these sets were used. How were these radio sets moved to Switzerland? The members of Station L seem to have had an uncanny knack to smuggle radio equipment into Switzerland.

I started work on the ZC.1 MK II, as it is in a bit of a state. The set is complete, it has the front protective cover, and there is a microphone, headset and CW key as well. The radio runs off 12 V, it has an internal mechanical vibrator power supply, and uses a 6V6 as modulator and 6V6 as RF output tube. All the electrolytic capacitors need to be replaced. A good cleanup is required, some rust is on the inside even though this unit is a tropicalized version. After a week or so, I had the basics of the ZC.1 functioning, the mechanical vibrator power supply section worked well, and I had replaced the high voltage electrolytic capacitor. Some clean-up work and more fiddling brought the ZC.1 to life, and it can now receive and transmit. Output is about 0.5 watts. Much work remains however, so I will continue to restore the set until it is in a satisfactory condition. Some capacitors will have their old innards removed, so that I can restock them with new innards, in order to preserve its original appearance. 

Radio shack update July 2022

Figure 90. Collins Radio TCS transmitter and receiver sets. The cotton covered wire used to connect the transmitter output to the loading coils were obtained from the Main Astronomical Observatory located near Kiev, Ukraine.

Figure 91. Bendix Type RA-1B receiver.

Winter. Our lowest temperature to date was -8° C. Quite chilly when you have to clean stables at -5°  C.  We have had no snow yet, except on the Drakensberg; this snow has melted a bit but a lot of it has remained since June. We expect to have some snow in August, as statistically, we have more snowfalls in August than in any other month.  

My world has been in a bit of a turmoil, so very little time could be spent on the Luven station replica. If you have a look at my Collins TCS sets photo in Figure 90, you will notice the neatly made up cotton covered wires connecting the transmitter outputs to the loading coils. I based this set-up on my Luven station notes. The cotton covered wire I received as a gift when I visited the Main Astronomical Observatory of Academy of Science of Ukraine, some years ago. Of course modern technicians and astronomers do not use cotton covered wire anymore, so the technicians of the satellite laser ranging station located at the observatory were only too happy to part with the couple of metres of cotton covered wire they had lying in a box. It has found a good home.  While visiting Kiev, I had a chance to explore some of the WW2 trenches and bunkers. I now find it terribly saddening that the people of Ukraine are once more undergoing the horrors of war. 

I found an RA1-B aircraft receiver in the shed. It has seen better days, but is restorable.  I am not quite sure about this, as it sounds a bit far-fetched, but according to my notes some of the Luven station members managed to scrounge/steal radio equipment that was installed in a Mosquito aircraft that was forced to land in Switzerland during WW2. The Mosquito crossed into Swiss air space and was forced to land. There is also a Bendix TA12-C transmitter with dynamotor power supply/modulator combination, as well as a CW key (MT11-B). Once I get round to working on the RA-1B/TA12-C combination, I will make a separate page for them.  A big box contains an MN26C compass receiver, direction finding loop, remote control, cables etc. There are also original manuals.  No doubt assembling/repairing this set-up will be a significant project. 

Radio shack update August 2022

Figure 92. Fully functional ZC.1 MK II transmitter-receiver, complete with 1940's Swiss made Avia wind-up pocket watch. The watch is a good time keeper.

Figure 93. The ZC.1 MK II. transmitter buffer coil, the damage to the coil can be seen. Exactly the same wire gauge was used and the coil re-wound as per the workshop manual specifications. 

Windy August. The Asian pear tree is in full blossom and the bees are having fun with the flowers; the forktailed drongos in turn, are having fun with the bees.

I had to rewind the low frequency band buffer stage of the  transmitter section of the ZC.1 MK II (Fig. 92). Somehow it had developed an open circuit in one section of the coil (Fig. 93), but this was soon sorted out. Now the LF and HF sections have about equal power output. The output is difficult to measure, as the output circuits do not match 50 Ohm loads, it seems happy with lower impedance. Judging from the input voltage and plate current, when tuned into a whip antenna of about 11 feet length, output is in the 1-2 watt region, certainly not more. So, now I have a nice WW2 QRP transmitter-receiver in fairly good working condition. 

A  Swiss-made Avia pocket watch from the 1940's I guess, was found in a black leather pouch, this must have been used by the Luven station operators, and perhaps it was the personal watch of one of the operators.  It fits neatly into the watch holder of the ZC.1 MK II.

Setting the transmitter and receiver to a frequency such as 7030 kHz is a bit of a task and requires an external frequency measuring unit such as a BC221. The graduation scale is in 100 kHz segments, i.e. one line is 100 kHz, quite different than modern rigs with their 10 or 1 Hz readout! The transmitter has some chirp, but who cares, if you are nearly 80 years old, you are allowed some chirp. The receiver frequency drifts, and the transmitter frequency drifts, but who cares, rather drift than sink. The drift just requires slight adjustment of the VFO dials, which must be done carefully and with great patience. 

I also had to realign the wafer switch that selects the different oscillator, buffer and output stage coils. Now all seems to be working fine. 

Radio shack update October 2022

Figure 94. DWS MK119-A transmitter/receiver. 

Figure 95. Marconi AD.94 aircraft receiver technical manual.

So I skipped updates on this page in September, and nearly October as well. My life has been in somewhat of a turmoil lately, so I have not had much time to work on the radio station. 

Good news is that I found some 805 tubes for the ET4335E. There are 2 new/unused tubes and four used tubes, and the used ones seem in good condition. I can now do some work on the modulator section. 

Unfortunately I have not had many CW contacts the last two months, as I just could not spend time in the radio shack. I did however have an uninterrupted 4 hour 2 minute session using the DWS MK119A, on 7025.2 kHz (crystal frequency), first with Andy (ZS6ADY) then Andy and Tom (ZS6OMT) and then with Tom only as Andy had to run off somewhere. This lengthy session gave me a very good hands-on experience with the MK119A (Fig.94). Frequency drift is always an issue, but only with the receiver, so constant checking against a BC221 (used as side tone monitor) and slight dial adjustments are required. I must admit that the set works very well, and is fun to use. Our CW speed must have averaged 18-19 wpm, as the Morse key (and my hand) attached to the fold-down door of the MK119-A box is quite happy at that speed.

I found some Hallicrafters equipment in a box. They will need some work before I can use them. There is an HT44 and SX-117 twin set, including the transmitter power supply. Much to my surprise I also found an SR-2000 (Hurricane) transceiver, very heavy power supply and an external VFO (HA-20). These radio sets date out of the 1960's. As I have not found any reference to these particular sets in my Luven station notes, I have no idea where they were used. Perhaps some information will surface later.

An interesting find as well, tucked away in a wooden box, was a Marconi AD94 HF/MF Aircraft Receiver, complete with (in near mint condition) original manual (Technical Manual Ref T.2217/2). Inside the manual (Fig. 95) is a note, "From Doreen D". The question is of course now who was Doreen D? The AD94 was built from 1949 into the 1950's.  There are some references to "DD" in my Luven station notes; reference to "DD" starts in June 1940. Perhaps these refer to Doreen D? Was she involved with the resistance in Europe? Or perhaps with the UDF? Or maybe both?


Radio shack update November 2022

Figure 97. Lt.Col. Doreen Dunning. The portrait was painted by Capt. Neville Lewis in 1941.

Figure 98. "The Castle", Doreen Dunning's home in the 1980's, viewed from the south. The thatched cottage to the right had two bedrooms, the main house had only one bedroom. According to the neighbour, during the 1980's there was a pine forest in the area beneath the house This forest was destroyed by a vicious wind/hailstorm that debarked the trees to such an extent that all the trees eventually died.

Figure 99. "The Castle" and thatched cottage. There is a stream and dam to the right; out  of view of this photo.

Figure 100. Small dam located on the border of the grounds, it is shared with the neighbouring property.

Figure 101. An older section of the dam is filled with lilies. It seems that a larger dam wall was constructed downstream, when the large dam is full, the two dams join with a waterway on the one side.

The question about "DD" has been on my mind a bit, so I have made an assumption, right or wrong, that "Doreen D" or "DD" might refer to Lt. Col. Doreen Dunning (Fig. 97). She was/is quite famous in that Doreen Dunning (née Hooper) was the first South African woman to obtain a pilot's licence (A-Licence, 1935, age 18), commercial pilot's licence (B-Licence 1935) and pilot instructor's licence. She was also the first woman to be called up for active duty (1 June 1940) during WW2, by Prime Minister Jan Smuts. So don't take what I write here as history or fact, I am just making an assumption, and I might be totally wrong. One thing is for certain however, she was an outstanding and amazing person. 

Doreen Dunning was one of the six founding members of the South African Women's Aviation Association (SAWAA) and was elected as SAWAA's first Chair. She was called up by Prime Minister Jan Smuts to head the Women's Auxiliary Air Force (WAAF), initially as a Major (at age 22), she was later promoted to Lt. Col., at the age of 24, which made Doreen Dunning the youngest, highest ranking officer (in terms of age) in the Commonwealth Forces. For those interested, there is an interesting write-up about the WAAF at WAAF history 1939-1945, by Major Marjorie Egerton Bird and Molly Botes.

After some scratching around, I found out that Doreen Dunning bought a house ("The Castle") on 10 Ha of land about 7 km from Underberg on the Drakensberg Gardens Road. This must have been about 1983. I will find the exact date later on. She lived there for 5 years. Apparently there was a landing strip, visible from her house. The landing strip was about 1.2 km long, and about 1.2 km from her house as the crow flies; it was located south-west from "The Castle".  This landing strip does not exist any more. I have been asking myself whether any clues could be found at this old house. Something in a cellar, hidden cupboard, stashed away in a ceiling, a hole in the floor...

Anyway, it will not be that easy, but at least I managed to take a photo of the house as it appears now (Fig. 98 and Fig. 99). I have made friends with the  gardener, and hope to gain access to the house for closer inspection. 

I walked the grounds on the 3rd of November, it has many large trees, two streams, the larger of these feed a dam (Fig. 100). Upstream from the dam is an older, lily filled dam (Fig. 101).

Quick update, 12 November: After scratching around a bit more, I found out that the roof/ceiling is unlikely to yield any secrets. The original thatch roof burned down in the 1980's whilst Doreen Dunning lived there, fortunately she could phone the telephone exchange and requested help, so in a short period of time neighbouring farmers had emptied her house of all contents; apparently they had formed a human chain and none of her belongings were lost to the fire. The roof was subsequently recovered with Harvey tiles, these were made of galvanized panels, painted charcoal. This roof existed up to about 2012 when it was recovered once more, this time with corrugated galvanized sheeting. I doubt whether anything hidden in the roof-space would have survived two re-roofings without being burnt or discovered.  During a tour of the house, I saw three ceiling trap doors, so it would be possible to enter the roof-space.

Radio shack update February 2023

Figure 102. The storeroom before refurbishment.

Figure 103. The old store room refurbished. This is the sitting room; to the right is my bedroom. There is a small bathroom which has a shower. One enters into a tiny kitchen, this has a kitchen sink,2 burner gas stove and tiny fridge. 

February already and not much to report on. I have been busy however, as I now work at "The Castle" as the local handyman. I found that there are five ceiling trap doors in the main house, but unfortunately I have had no reasonable excuse to grab a ladder and crawl around in the roof-space. I live on-site a part of each week, and have been given an old store room (Fig. 102) to fix up as my living quarters. This was a messy affair as the roof leaked, the shower missed a tap, and the floor was in a bad state. The ceiling is only 1.8 m high, which is fine, as long as I don't stand on my toes. I have patched the roof, sanded down and sealed the pine floor (Fig. 103), fixed the plumbing, replaced light fittings, and painted the walls with a moisture sealer. The walls need to be given a final coat of paint. 

Anyway, I have made the proposal that Doreen Dunning's bedroom be turned into a small museum, and this proposal has been received quite well. It won't happen instantaneously, but I will tinker on it as I find the time. 

Radio shack update August 2023

Figure 104. View from "The Castle", early autumn, looking south over the Umzimkulu River valley.

I cannot believe that I have missed so many monthly updates. Yet I have, and there are no excuses to be found either.  My number of CW contacts per week has dwindled a lot,  and I have to set aside time on Saturday afternoons to try and join the ZS0AWA (Antique Wireless Association) net, where one can normally find a couple of CW users, Andy ZS6ADY (net controller), Ed ZS6UT, Tom ZS6OMT, Evert ZS6AQW and Dave ZS6AZP. The net operates on 7.025 MHz at 12H00 UTC. I mostly use the MK119-A on this net, as I have a crystal that oscillates on 7.0252 MHz, which is close enough in my books. Nobody has complained.

Have I found anything of interest at The Castle? Not really, I found an old wooden fold-up ruler, an empty pince-nez case, and a reel-to-reel tape containing 6 episodes of Hancocks half hour (British comedy).  The episodes are from series 4, these were broadcasted by the BBC from 14 October 1956 to 24 February 1957. I still think I am going to discover something of interest.  Under the guise of inspecting a geyser, I climbed into the ceiling of the kitchen of the main house, and saw that were still burnt roof logs (due to the 1980's fire when the thatch roof burnt down) protruding from one wall, so I think the kitchen was added later, as the wall was painted (so would have been an exterior wall) and the add-on section not.  The views from The Castle is spectacular (Fig. 104).

I have done some work on the Hallicrafters SR-2000 (Hurricane) transceiver. One of the driver coils were broken, so I removed it and wound another on a better quality adjustable former. 

Radio shack update December 2023

Figure 105. Chicken Coup radio shack. 

Well, what can I say? I have been under the radar a bit, hiding from something, but here I am. The Hallicrafters SR-2000 is still sick, although the driver section works fine now. There is an old store here at The Castle, on the building plan it is listed as a chicken coup, but it is definitely not a chicken coup. Apart from no chickens currently, no signs of it ever having been occupied by chickens can be found. I also found the remnants of two cut-down wooden (pine) poles, separated about 43 metres from one another. The poles were treated with creosote, so the remnants are still well preserved. Each pole had three galvanized anchor sections, these have been cut, but the bottom sections were found after digging around a bit. I reckon they were antenna masts. As the Chicken Coup is centered between these remnants, it is very likely that the poles were used to support a wire antenna, and the Chicken Coup was a radio shack, or at least housed some radio equipment. One section of the Chicken Coup is presently used as a firewood store, the other part had some old furniture in it, and a 3rd section is full of odd pipe sections and timber. Most of the building is currently covered with shade netting, which gives it the appearance of a run-down shed.   


Figure 106. Side view of the Chicken Coup radio shack.

Fig. 106. Inside view off the radio shack, very tatty, and will require major renovation.

The dimensions of the three sections of the Chicken Coup are 3 x 5 metres,  3 x 4 metres and 3 x 2 metres.  There were no radios inside of course, but a bit of a give-away was the discovery of a box that obtained some radio spares, in the form of plug-in cards. The cards are populated with TTL logic IC's, late 1960's early 1970's discrete components, and a rough drawing of what could have been the shack. There seems to have been three small rooms, as per the dimensions given above, although some of the walls have been taken down and will have to be rebuilt. The largest section is still intact.  There might be more clues in the section that contains pipe and timber, but that is so cluttered at the moment that one cannot see what is there, except for the pipe and timber. It will need a major clean-out and a truck to cart away useless junk. This section has some 3-phase junction boxes, and armoured cable. I tested it but it is not connected to the main 3-phase supply. According to the drawing, which is nothing more than a couple of lines drawn by someone, the largest of the rooms (3 m x 5 m) is marked "OPS", the smallest room "Office" and the 3  m x 4 m section is marked "T". There seems to have been steps down to the "T" section as it is at a lower level and has a higher ceiling height than the other rooms.  The remnants of the foundation show that there was a large door on the eastern side. There are no ceilings and there are holes in the roof. 

Radio shack update April 2024

Fig. 107. One of the cottages at The Castle. During 1983, Doreen Dunning lived in the left side of this cottage. At that stage there were two separate cottages, the center section was added later and the roof modified to join the two cottages into one. She lived here for a year before she bought the property and after some additions to the main house, moved to the main house. 

Well, time flies as we all know. It would seem that I will not be able to rebuild the complete radio shack at The Castle as I had envisioned. However, I will do what I can. I was fortunate enough to obtain a book (kindly donated by her son Dr Richard Dunning) that Doreen Dunning had written about her life. The book is entitled "Sky High". It is indeed a very interesting book , and I have retraced the things she mentioned about The Castle when she lived there. She first rented the premises for a year and then bought it. 

Radio shack update September 2024

Fig. 108. Run-away fire close to The Castle. I used a tractor equipped with water tank and high pressure pump to help with controlling the fire. Many members of the local community assisted.

Fig. 109. Block diagramme of the Rohde & Schwarz XK 310 transceiver system. 

Fig. 110. XK 310 cabling of system and remote control GB 002.

Fig. 111. Heavy snow and ice on the wire antennas of the WW2 radio shack damaged the supporting poles.

September. The winter at The Castle was dry and we had no snow, only a few mm of rain. Run-away veld fires surrounded us and I had to help with several of these. Fortunately we managed to control the fires. Snow is still predicted, so one can only hope. The fountain where we source our water from has all but run dry, so we are now relying on what water is left in the 40 kl storage tank. 

I have found more information about Doreen Dunning and have probably exhausted what can be found in the public domain.  I have had very little time for radio related matters.  

It would seem appropriate though to equip the radio station at The Castle with radios from the mid 1970's to the late 1980's as I found a very tatty notebook that has some reference (block diagrammes, specifications, wiring notes etc.) to Rohde & Schwarz (XK 310) (see Figs. 109 - 110) as well as Siemens (CHX 240) equipment.  There seems to have been two XK 310 systems and one CHX 240 system. Both the XK 310 and CHX 240 had automatic antenna tuners and must have been very expensive when new.  The XK 310 is a 1 kw output multi-mode system whereas the CHX240 is a 400 watt multi-mode system. It would appear that the Siemens transceiver was linked to a Siemens T1000 teleprinter.

I still do not have any clarity about the antennas that were used. It would have been something that did not attract attention, perhaps a large whip/rod type antenna, combined with a multi-band dipole, or even a travelling wave dipole. I am nearly certain that there was no tower installed as I have found no evidence of a concrete tower base.  I don't think any of this equipment can be found in South Africa though.  From what I could garner from the internet,  the XK 310 transceiver systems were used in German submarines, warships, trucks and stationary land-based stations. The CHX 240 transceivers were used in German Command and Control bunkers and mobile Command and Control trucks. Perhaps I will uncover more information. These were all Cold War radio communication systems. The XK 310 date from the early 1970's and the CHX 240 from the early 1980's. 

What would they have been used for? I doubt that these transceivers were ever bought by the ordinary citizen, the cost would have been prohibitive; they could only have been bought by a government or large company/organisation.  

The CHX 240 consists of:


According to the notes I have, the R & S XK 310 consists of:


The XK 310 and CHX 240 transceivers are functionally quite similar in that they are multi-mode, receive from 10 kHz to 30 MHz, transmit from 1.5 MHz to 30 MHz, frequencies can be set in increments of 100 Hz, and both have preset channels (xK 310 has 10, the CHX 240 9 channels). 

Available modes are:



Update 23 Sept 2024

As predicted we had some snow on the 20th and 21st of September. The WW2 replica radio station had quite a rough time as ice and snow built up on the wire antennas. This caused the antenna masts to bend and break some feet from the top end. I can repair them, but it is a pity nevertheless (Fig. 111).  Even more snow fell at The Castle, about 30 cm (Fig. 112), fortunately the temporary wire antenna there did not suffer any damage. 

Fig 112. The Castle is located in the foothills of the southern Drakensberg. I have circled the location of The Castle, the small town of Underberg is visible in the forefront.

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