JakLomas Posted February 8, 2014 Share Posted February 8, 2014 Hi, I recently bought a Clansman 352 and GSA, but I have no idea what these parts are or do! I presume there part of the GSA Assembly? Roll of coaxes marked with thing like 30-53 MHz, (frequency ranges)? Rope/string? Inductor unit, R.F.? NSN. 5985 99 630 6500? Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
g0ozs Posted February 8, 2014 Share Posted February 8, 2014 Jak This is most of the elevation kit for the ground spike antenna used with a 5.4 metre fibre glass mast. There is a metal adapter that fits the GSA base unit to the top of the mast (photo no. 4). The appropriate short coax for the frequency in use (one from photo no. 1 I think) goes from the GSA base unit down to the inductor unit (photo no. 3) that should be clipped to the mast. The normal long GSA coax then connects the bottom of the inductor unit to the radio. The combination of the correct length coax and the inductor unit provides a simulated ground for the GSA to produce the correct radiation pattern and a half decent match to 50 ohm radios. The nylon cord (Photo 2) is used when the GSA is suspended e.g. from a tree rather than on a mast. The key to success is to ensure that the strain relief cords and collars are used correctly and none of the BNC connectors are bearing the weight of the cable and inductor. You can improve the odds by putting a few turns of tape round the mast below the inductor if its springs are tired and weak, so it cant slip down. Inside the inductor unit are about 1/2 dozen turns of thin coax on a ferrite ring - so you can make a more mechanically robust version for a single frequency by using a longer than necessary coax from the GSA base to the radio and coiling up the spare at the same distance as the inductor would be below the antenna for that frequency and then securing the coil to the mast - that way you have two less BNC connections to come loose after the mast is up ! I think (I dont have a set to measure easily to hand) the cables between the GSA base and the inductor unit are 1/4 wave long. If you could measure the ones you have and list the lengths and labelled frequency ranges it would help me with something ! Regards Iain 73 de G0OZS Quote Link to comment Share on other sites More sharing options...
JakLomas Posted February 9, 2014 Author Share Posted February 9, 2014 Hi Iain, I don't have the cables to hand at the moment but I will measure them on Tuesday, hope this is ok. Regards, Jak Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.