A Vertical Antenna for SOTA (a project I am still working on)

The vertical has had a number of runs since the first post.
I have not actively compared its performance to my end fed antenna. But it seems to be no less efficient as I have worked a few JA station on 18MHz when using it.

The design remains similar with the exception of adding a 1:1 current balun. This was introduced to isolate the coax from the antenna system, as I noted some variation in VSWR as the coax was moved. This was discussed here on the SOTA reflector (look for post #7)

I have remained with the3.7m radials but I have increased the number to 8 (yet to be tested).
After reading An experimental look at ground systems for HF verticals (second link below) I may increase that number to 16.

Further Reading;


Naturally the internet is most people go to when it comes to research, to date I have turned up three items of interest

Some Rules of Thumb for Ground Radials

I have also found some interesting reading by Rudy N6LF, Rudy has done a huge amount of work with antennas. two articles caught my with regard to radials for vertical antennas;

First one, on this page look for Series of QEX articles on ground system experiments
The summary of these articles are covered in this document Download QST March 2010 Ground Systems

The second one looks at radial length for shorter verticals, one this page look for Are the lengths of radials related to the height of a vertical? to find the article Vertical height versus radial system


Radios for Goats


I have used four different radios for my Parks and Summit activation’s.

By far the majority have been done with either of my two KD1JV rigs the MTR and ATS4. Both these rigs run on little power and their compact size makes them quite portable. Batteries are external and if required the ATU is also external. This does make set up a little more time consuming but does provide other advantages such as rig cannot be turn on by accident in the pack, and an external ATU allows the active part of the antenna to be placed a little bit further away from the operator.

ats and mtr

ATS4a and MTR 2 bander

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