South Dorset Repeater Group News
(Page updated 03/02/17)
The latest News entry is at the bottom of this page - use the 'End' button on your keyboard!
GB7SD LICENSED Much to everyone’s surprise, the NOV for GB7SD was issued on the 20th of January. It was expected that it would take many months before the licence application was processed by OFCOM and the Primary User and that it would probably be an agenda item at this years SDRG AGM in November!
As well as GB7SD, all the other proposed DMR repeaters, including GB7JB at Willoughby Hedge and GB7DR at Poole have also been licensed. This has therefore caught everyone unprepared and it will be some time before they are all operational.
ETCC The Emerging Technology Coordination Committee of the RSGB functions to develop and enhance the UK Amateur Radio Repeater Network together with data communications systems and to promote the introduction and roll-out of appropriate new technologies. The ETCC handles all applications for and/or changes to existing Repeater NOVs. Our local representative, Andrew, G8DOR, is the ETCC Member for the South West of England and is the first point of contact for any queries about Repeater Licencing in the South West.
See: www.rsgblicensing.org.uk/etccsecureforms/e1-secure.php for more information.
DIGITAL FUND The matter of funding the Digital Repeater Network was discussed at the 2013 SDRG AGM and it has now been decided that a 'Digital Fund' should be set up by the SDRG to enable supporters to contribute towards the cost of the digital repeater hardware. This will include the actual repeater transmitter/receiver and the aerial system and duplexer.
The fund will be administered by the SDRG Treasurer but kept separate in the accounts. Payment can be made in the usual way, either by using the PayPal option on the Groups Website, or by sending a cheque made out to 'South Dorset Repeater Group 2000' to the Treasurer: Rob Mott, G0ECX, 2 Dennis Road, Weymouth, Dorset DT4 0NJ Please mark your payment 'digital fund'.
The status of the fund can be found on the GB7SD page.
Chris, G6WHI has already assembled a complete system using a Motorola Repeater and this has been successfully tested on air and this will be demonstrated at the next SDRS meeting on the 11th of February.
GB3DR TO MOVE SITE Because of the recent offer of the Eggerdon site for the proposed DMR repeater GB7SD, the possibility of moving GB3DR to Eggerdon has been investigated. This was briefly discussed at the SDRG AGM, in that the availability of the Eggerdon site would give the Group a fall-back position should the Ridgeway site become untenable for any reason.
Over the last few years our local 2M repeater GB3DR has suffered from a multitude of QRM/QRN problems. Whilst most of these have eventually been traced and cured it has required a huge amount of time and effort by everyone involved in running and maintaining our repeaters. Over the 2013 Christmas period the repeater became almost unusable and Chris, G6WHI spent many hours on site trying to find the problem. Thanks to his selfless efforts, GB3DR is working as well as it ever has although we still have on ongoing intermittent crackling problem caused by sections of our tower moving against each other. At times this can seriously effect the readability of weak signals.
The VHF coverage from the Eggerdon site is fairly well known as there is already a VHF repeater there used by Chris and Mike (DMR Networks). The conclusion is that the site will give very good mobile coverage over a larger area of Dorset (and beyond) than is provided by the current site - it would therefore be an excellent 'regional' repeater site, exactly what 2M repeaters are supposed to be.
At Eggerdon everything will be under our control as the site is not shared by other users. Also the tower will be a solid assembly, very different than the telescoping sectional Versatower that we are now using at the Ridgeway site, so the main cause of the crackling problem will not exist.
Coverage using hand portables, particularly in and around some parts of Dorchester, Weymouth and Portland will not be quite as good but of course GB3SD will still be located at the Ridgeway site and hopefully it can be improved to give even better coverage than it has at present, and of course it will still be connected to the WWW using Echolink. If all goes well GB3SD and GB3DR together, will give an enhanced service covering a bigger area than is presently covered.
Following a consultation of SDRG members and users of GB3DR it has now been decided to apply to move GB3DR to the Eggerdon site. If that application is successful then the move will go ahead as soon as possible.
The South Dorset Repeater Group has never stood still. We have moved site before, and in fact have also considered Eggerdon twice before, both for GB3SD and a 2M repeater. We have made changes to our stations whenever it seemed the best way to progress our basic aim - that is to give our users the best possible Amateur Repeater service.
GB3DR SITE MOVE The move of GB3DR has been approved by OFCOM and the NOV was issued on the 4th of February. The move will take place as soon as possible. However there will be a slight delay whilst a new mast is erected at the Eggerdon Hill site.
GB7SD INSTALLATION The new Digital (DMR) Repeater installation will also take place as soon as possible but again will have to wait until the new mast is erected at Eggerdon.
DMR NEWS Clearly things have moved much faster than we expected! When we took the decision at the AGM to proceed with a DMR digital repeater I expected that it would be the next AGM in November of this year when we would be discussing progress and possible start up! After the AGM, when we found out that not only were we (GB7SD) applying for a DMR NOV but that Dave, G3ZXX (GB7JB) and Mark, G4SDR (GB7BS) was as well, the possibility of a local area network looked a real possibility. However it was quickly realised that many existing members of our Group located in the Poole Bournemouth area needed something closer to provide a solid service, so in view of the expected time delay in obtaining a licence (NOV) it was decided that Les would apply immediately for a DMR repeater (GB7DR) to be located at a site that was available at Mannings Heath.
The fact that all these repeaters are already licensed means that we have had to make decisions much sooner than we expected. As neither the Eggerdon Site or the Mannngs Heath site are expected to involve much if anything in the way of running costs, only the capital costs of the DMR Repeaters needs to be found now. The SDRG is hoping to source all of the hardware we need for the repeaters themselves at reasonably low costs and also hopes that it will be possible to provided DMR rigs at very attractive prices to Group members. It is worth bearing in mind that a digital repeater is perfectly suited to FM use as well, so if SDRG held a spare it could serve equally well as GB3SD. The expected cost is likely to be far lower than some other local Groups have spent on FM only Repeaters and no additional control logic is needed.
SDRG is working closely with all the other Groups that are expected to link together and become part of what is now being called a 'cluster'. There are no plans to link to DMR-MARC (at least for now). Locally, GB3SD, is already connected to Echolink, which is a well established network that works well and is very inclusive, in that there are many more ways to use it than any other Amateur Radio Network. Our proposed DMR Network will be promoted for what is does well, and not, at least for now, as a replacement for what we already have. DMR will complement and co-exist with our analogue network, especially since anyone with a UHF DMR/FM radio would also have access to GB3SD.
DMR Radio Talk at SDRS February Club Meeting A very well attended meeting was given an excellent talk and demonstration by Chris, G6WHI. Chris was able to show various Motorola and Hytera Mobiles and Handys in operation, both via repeaters and simplex. Chris explained that it was intended to form a 'cluster' of DMR Repeaters covering a large area using IP linking via the Internet. He also said that Software was being developed to generate unique ID numbers for each radio on the network using the owners callsign. This method would mean that it would not be necessary to have and maintain a formal registration and record system.
There was so much interest from the very attentive audience that the question and answer session eventually ran out of time!
Geoff, G0EVW 13/02/14
Eggerdon Site News The new mast has been erected and the first thing on the agenda is to move and install GB3DR. A purpose built professional quality aerial and fittings has been ordered and once delivered it will be erected as soon as time, weather and work commitments permit. Work on the mast which involves climbing can only be carried out by a qualified rigger. The installation of GB3DR will follow as soon as possible.
GB3DR to Close Down! GB3DR will go QRT at 2200 BST on March 31 2014 until it can be switched on from the new site at Eggerdon.
GB3DR returned to full service from the new site at approximately 1600 BST on Tuesday the 1st of April 2014.
Update 06/04/14 GB3DR is working well and the coverage from the new site is excellent although obviously some people that were very close to or line of site to the old site will have a weaker signal. There is a slight amount of interference from a co-sited Digital VHF Repeater at the moment but hopefully the high quality band-pass filter that we have will cure that once it is installed.
Update 07/04/14 The GB3DR Repeater was changed yesterday and we are now using the original one that was at the Ridgeway site. The bandpass filter was tried but did not reduce the interference from the co-sited digital repeater. Other measures are now being investigated.
The Group has obtained some interesting data from Chris, G3VEH about spacing aerials off of a tower structure that was published by Pye many years ago. Using this data it seems that a 1/4 wave spacing from the East side of the mast would be best for us and hopefully this will be done at the same time as the GB7SD aerial is erected. Repeaters are supposed to be omni-directional of course and hopefully this will result in a better distribution of signal from our site as at the moment there probably is a slight null to the East caused by a rather distorted radiation pattern.
GB7SD News Update 17/04/14 Please note that this project is currently on hold. A further update will be posted here as soon as the committee has met.
GB7SD News Update 23/04/14 At the committee meeting last evening it was confirmed that the proposed site for GB7SD is no longer available. More detail will follow:
GB3DR News Update 24/04/14 The aerial is now spaced 1/4 wave length off of the tower. This was done over the Easter Weekend and initial reports suggest the the coverage to the East is now improved and overall is much more as was originally predicted.
Committee Meeting 22/04/14
The South Dorset Repeater Group (SDRG2000) held a committee meeting on Tuesday the 22nd of April. Here is a summary of that meeting. The minutes of the meeting are now available to SDRG members - please contact Les, G0FAJ: email@example.com
GB3DR: The committee is pleased with the way GB3DR is progressing and the coverage to the East is better now that the aerial spacing off of the mast has been changed to 1/4 wavelength. It seems that the vast majority of users are satisfied with the new arrangement. Attempts will continue to cure the interference from the co-sited commercial Repeater. As a direct result of the increased coverage we have picked up at least 7 new Group members.
GB3SD: As promised, we will try and improve GB3SD with new aerials that should result in a stronger signal and overall better performance. Hopefully this will compensate those that have lost out in the move of GB3DR to Eggerdon. This will hopefully be done in the next few weeks. The suggestion is that an omnidirectional stacked dipole array will be mounted at the very top of the mast and used for transmit so that our ERP should be back up to the full 25W. A pair of dipoles, one stacked above the other will be mounted on the East side of the tower and used for receive. Another pair of dipoles will be mounted on the mast to facilitate the tests with GB7SD (see below). It should be noted however that final arrangement of the aerials is not set in stone and it might be that some other configuration might work out better for a majority of users. The Internet Link to GB3SD using Echolink is not affected by any of these proposals and continues to work well.
GB7SD: It was confirmed at the committee meeting that installing GB7SD at the Eggerdon site as was originally planned is no longer possible. The committee is very keen not to give up on the digital project and it was therefore decided to consult the membership as widely as possible and have an EGM in June suggesting that GB7SD is installed at our Ridgeway site. This is now possible as moving GB3DR to Eggerdon has made room in the cabinet and on the mast for another installation. Meanwhile tests will take place to make sure that this can be done without any interference between the two repeaters. An offer to operate GB7SD from the Eggerdon site using a temporary aerial (a single dipole at 20ft AGL) until GB7SD was permanently installed at the Ridgeway site was discussed at length but not taken up.
As well as getting approval from the membership to permanently install GB7SD at our Ridgeway site another very important topic of discussion must of course be the funding of the digital project. At the time of writing this report, the 'Digital Fund' stood at £559.55 but as with the successful relocation of GB3DR that has already generated new income for the general SDRG fund it is expected that once GB7SD is up and running more contributions will be made to the digital fund. Meanwhile contributions to the digital fund are of course welcome now and details on how to pay can be found on our website: http://gb7sd.co.uk Any other matters that might affect the proposal will also be discussed at the EGM and if any member has a particular question or matter they would like discussed they can submit details to the SDRG Secretary Les, G0FAJ either in writing or by e-mail: firstname.lastname@example.org
The date and time set for the SDRG2000 EGM is 7:30 for 8:00 pm on Tuesday the 3rd of June and it will be held at the Weymouth College – Dorset Skills Centre, Unit 1-3 Parkway Farm, Dorchester DT1 3WA. There is ample free parking at the site and snacks and refreshments are available from vending machines. Would all SDRG2000 members please do their very best to attend.
73 de Geoff, G0EVW - Chairman and Repeater Keeper SDRG
10/05/14 A request for a site change for GB7SD is currently being processed by RSGB.
GB3SD NOTICE OF PLANNED WORK It is hoped to carry out some work at the Ridgeway site next Saturday the 17th of May - weather permitting. We hope to carry out the promised improvements to the GB3SD aerial system and a number of other jobs. An omnidirectional stacked dipole array will be mounted at the very top of the mast and used for transmit. A pair of dipoles, one stacked above the other will be mounted on the East side of the tower and used for receive. Another pair of dipoles will be mounted on the mast so that we can undertake the test transmissions for the proposed GB7SD DMR system. This will involve dropping the tower, so GB3SD will be off the air for a few hours.
17/05/14 All the planned aerial work was completed today and GB3SD is now fully operational again after being QRT for a few hours.
28/05/14 Over the last few days a series of tests have confirmed that it will be possible to operate GB7SD from our Ridgeway site without mutual interference between it and GB3SD although at the moment the GB3SD receive aerial and the GB7SD TX/RX aerial are currently too close together and additional filtering would be needed. However another possibility is to re-site and reconfigure the GB7SD aerial as at the moment the radiation pattern from it is far from ideal. This was well demonstrated when for a 24 hour period the GB7SD aerial was used for GB3SD transmit!
04/06/14 The EGM of the SDRG took place last evening to discuss the proposal 'that we install a DMR Repeater (GB7SD) on our Ridgeway site as soon as possible and that to enable this we should purchase a Motorola DR3000 Repeater system'. After an informative discussion and consideration of a comment on funding received by e-mail from a member who was not able to attend the meeting, a vote was taken and as there were no objections to the proposal on the agenda the DMR Repeater will be purchased and installed as soon as possible. The Digital Fund will be topped up by a loan from general funds to enable the purchase. There is still some work on the mast and the GB7SD aerial system that needs doing and of course we have to wait until the NOV is granted but hopefully GB7SD will be on air soon.
09/06/14 GB3SD/GB7SD compatibility tests: Yesterday evening Rob, G0ECX tried a different configuration of the aerial system using the same TX aerial for both repeaters but separate aerials for RX. This worked perfectly with no detectable de-sense to either system so we are now ready to install GB7SD as soon as the NOV arrives. Not surprisingly Colin, GW3WSU reported identical signal strength from both repeaters at his QTH in Barry. There is still some outstanding work needed on the mast and the GB7SD RX aerial but this should not delay switch-on.
17/06/14 The Group has taken delivery of the Motorola DR3000 DMR Repeater and it is hoped to do some test transmissions from the Ridgeway site this coming Saturday the 21st of June. Users of GB3SD should expect some interruption of service as the mast has to be dropped for maintenance. Also the GB7SD receive aerial has to be reconfigured and moved to a different position on the mast before the tests take place.
06/07/14 Both GB3DR and GB3SD continue to work well with no problems. We are still waiting for the revised NOV for GB7SD but as soon as it arrives we are ready to go DMR! Rob, G0ECX is giving a talk on DMR to the Poole Radio Society on Friday the 11th of July. See: www.g4prs.org.uk
12/07/14 The illustrated talk by Rob, G0ECX at the Poole Radio Society about the DMR/TDMA technology that is being used in the new generation of Amateur Repeaters was a great success. With help from Les, G0FAJ a working demonstration of GB7SD (running on a dummy load) was given using a selection of DMR transceivers. DMR is the fastest growing Amateur Digital Network in the UK. See here for more information about DMR in the UK: www.dmruk.net
In appreciation the Poole Society generously paid a life membership fee to SDRG and this will be used to boost the digital fund. Considerable interest was also shown in the proposal to install a DMR repeater in the Poole area (GB7DR). A member of the Poole Society also joined the SDRG. Rob has agreed to give a similar talk to the South Dorset Radio Society in the Autumn and also investigate giving the talk to other local clubs.
2014 Annual General Meeting
16/09/14 A provisional date and time has been set for the SDRG2000 AGM. It is 7:30 for 8:00 pm on Tuesday the 18th of November and it will be held at the Weymouth College – Dorset Skills Centre, Unit 1-3 Parkway Farm, Dorchester DT1 3WA. There is ample free parking at the site and snacks and refreshments are available from vending machines.
73 de Geoff, G0EVW - Chairman and Repeater Keeper SDRG
31/10/14 The NOV for GB7SD was issued today and our DMR Repeater should be operational very soon!
01/11/14 GB7SD was switched on this afternoon. We are currently using Colour Code 1 and Talk Group 1 on both slots.
04/11/14 The 2014 Autumn Newsletter is now available to read here: SDRG Newsletters
11/11/14 Mike, G8NIC has taken over as Repeater Keeper for GB3DR. Mike is also the Keeper of GB3YS. Geoff, G0EVW remains as Keeper for GB3SD and GB7SD.
16/11/14 Our AGM and a Junk Sale will be held this coming Tuesday the 18th of November at the Weymouth College – Dorset Skills Centre, Unit 1-3 Parkway Farm, Dorchester DT1 3WA. There is ample free parking at the site.
18/11/14 A very successful and well attended AGM and 'Junk Sale' took place this evening.
10/12/14 The Ridgeway end of the microwave link to Dorchester has been installed and tested. Once the Dorchester end is installed GB7SD will be connected to the SW DMR Cluster.
16/12/14 Since initial switch-on GB7SD has been using Colour Code 1 and Talk Group 1 on both Slots. This is currently being changed to TS1-TG9 for local repeater traffic and TS2-TG950 for access to the South West Cluster, which includes GB7BS, GB7AA, GB7JB, GB7SD and GB7DR. It is recommended that all users change to these settings as soon as possible.
17/12/14 In order to ease the transition to the new Talk Groups some of us will have TS1 programmed with both TG1 and 9 available when using GB7SD. See the image here for a typical channel allocation on a Motorola DP3400.
16/02/15 GB7SD is now connected to the South West Cluster - currently GB7AA and GB7BS.
21/02/15 The GB7DR web page now has a direct link: gb7dr.co.uk
12/03/15 GB7JB is now operational and connected to the South West Cluster - see: www.gb7jb.blogspot.co.uk
20/03/15 GB7DR is now connected to the South West Cluster.
24/11/15 GB7SD is currently disconnected from the South West Cluster pending realignment of the microwave dish that links it the the Internet.
The ANNUAL GENERAL MEETING of the Group will be held at the Weymouth College Dorset Skills Centre, Unit 1-3 Parkway Farm, Dorchester DT1 3WA on Tuesday the 1st of December at 7:30 for 8:00 pm. This is the same venue as we used last year although we will probably be in a different room. There is ample free parking at the site and everyone who has any interest in our Repeaters is welcome.
06/12/15 GB7SD is now reconnected to the South West Cluster.
07/03/16 The aerial currently being used for RX is suspected to be faulty and the RX performance of GB7SD is therefore rather poor.
04/04/16 The aerial currently being used on RX is a new single folded dipole. The RX performance might therefore still be a little down.
03/02/17 The Group has a new committee. Full details on the SDRG Information Page.