Topband: Using 80m 1/4 vertical on 160

[Ashton Lee]

I have the zero five 55 foot antenna which was custom built to actually be a full sized 80 meter antenna. It was affordable and has stood up well on a very windy mountain top. Performance is, of course, no different than a 65 foot wire…. if you had trees to support the latter.





On Jun 3, 2014, at 1:43 AM, Ray Benny <rayn6vr at cableone.net> wrote:

> Mike,
> 
> Can you find or provide more info on these 80m zero-five verticals? What
> does zero-five mean or stand for?
> 
> I though about using relays to switch in/out the top loading wires for
> 160m, but computed the voltage to be over 10 KV. Vacuum relays to handle
> that voltage are very expensive. Then there is the issue of protecting them
> from harsh WX.
> 
> Ray,
> N6VR
> 
> 
> On Mon, Jun 2, 2014 at 9:39 PM, Jim Brown <jim at audiosystemsgroup.com> wrote:
> 
>> On 6/2/2014 6:07 PM, John Kaufmann wrote:
>> 
>>> Perhaps top loading would be somewhat more efficient on 160,
>>> but it would be difficult electrically and mechanically to switch out top
>>> loading on 80.
>>> 
>> 
>> Not as difficult as you might think. Certainly worth some modeling. Add a
>> 80M trap at the top between the vertical and horizontal portions. Below 80M
>> that circuit would look inductive, which adds loading on 160. In the model,
>> play with values for the trap and the top wires to maximize efficiency. My
>> guess it that might be good for another dB or two.
>> 
>> 
>> 73, Jim K9YC
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