Communication range and antenna types

As a "staybehind" type of radio communication installation which developed from the initial WW2 radio shack, there were certain objectives in terms of communication range which had to be met. During the 1940's, the station had to be able to send and receive CW messages (enciphered and in plain text) as well as AM voice messages within a region with a radius of about 2000 km. This region extended into the UK, Norway and Finland. Much of the communication was well inside this radius. After WW2 the need for a 2000 km operational range remained, but in addition and specifically from the late 1950's, there was also a requirement to reach the USA.

If they had a free hand I am sure there would have been an "antenna farm" with rhombics and large steerable log-periodics. None of these types of antennas were installed. From the sketches I have, the antennas were very modest and unobtrusive. The antennas had to be unobtrusive so as not to draw unnecessary attention, therefore they did not look much different than typical late 1930's household receiving antennas. Any radio amateur activity (transmitting) was not allowed in Switzerland from the outbreak of WW2 until September 1945, but all citizens were allowed to use radio receivers.

The Collins 37B-2 end-fed inverted L type as described below was used at the station, it was also used in field operations as well as were whip and vertical rod type antennas. In the 1940's the station had some RCA type doublets as well as a double extended Zepp, a multi-band dipole was added in the mid 1950's (see Figure 1). Only in the early 1960's a three element full-size mono band beam (Mosley) was added, followed by a three element tri-bander in the mid 1960's. From what I could gather, the Mosley beam was built to receive WWV on 10 and 15 MHz, but the operators removed the trap coils and adjusted the element lengths to operate on 13.2 MHz. I can easily adjust this antenna to operate on the 20 m amateur band as it would be useless as it is. I suppose this was done on the instructions of some agency in the USA.

In addition, there were two short vertical aluminium rod antennas, these had a length of about 6 m. A double pine pole formed the bottom support of these rod antennas, this setup raised the rods above roof level. They were installed very close to the radio shack, and were used with two of the four Collins TCS sets.

The radio shack had an arrangement of double-throw, double-pole knife switches, also a large solenoid driven relay, to switch antennas between equipment. Both balanced feedline (ladder line) and coax cable were used. There were no towers installed. The beams were installed on a pine pole assembly (mono-bander) and a crank-up mast assembly (tri-bander).

The effect of this was that during WW2, the antennas used were similar to those installed all over Switzerland for broadcast reception. So up to about 1949 only very unobtrusive wire antennas (doublets) were used. Thereafter, the shack had the appearance of an amateur radio station in Switzerland, complete with copies of the "old man" HAM magazine published by the Union Schweizerischer Kurzwellen-Amateure (USKA), (Union of Swiss Shortwave Amateurs). It could easily have passed as just another, fairly upper class HAM radio shack. This of course fitted well into the "stay behind" mind set. In other European countries, similar stations were established during the 1950's and even up to the 1980's. It did not have the appearance of a "government type" installation. In fact it seemed very innocent and normally had a number of cows standing about, cheerfully munching grass, and the cows did not care about WW2, the Cold War, or what the politicians were talking about.