[ADXA] Get 160m inv L to 80m?

[rcurt at centurytel.net]

I also would like to get my 160 meter inverted L to work on 80, and your email has made me think about a solution.  I'm thinking that adding a separate radiator with a bit of spacing, may be a solution. I will try this at some point, but at the present, it is a couple projects and a few degrees warmer down the road. I'm listening carefully for the solution. By the way, great job last night on 160. I saw you work several stations while I was at the operating position from about 8:30pm to just after midnight. 


Good luck
Randy/W5ZJ


On Thu, 20 Feb, 2025 at 11:25 AM, Jussi Eloranta <eloranta at aa6kj.hoptoorg> wrote:
 

To: 'adxa'

Hi Pat,

On 2/20/25 11:09, Pat Patterson wrote:
> I use a coaxial trap...RG214 on a piece of 4" thin wall PVC. Trap 
> resonates at 3.45 MHz.
>
> Looked at using a vacuum relay...lower losses but more complexity.
>
Thanks. Yes, I would like to avoid relays... I have currently a shunt 
coil in place so that I can get the feedpoint impedance close to 50 ohm 
on 160m. With that coil in place, I checked the antenna with analyzer 
and noticed that there is some sort of resonance very close to 3.5 MHz 
(X = 0) but there R is around 5 - 10 Ohms (with the 160m shunt coil in 
place). Of course, probably need to do eznec to make sure that this does 
not end up being an EME antenna (take off angle towards the moon) :-)

Can you give some more details on the trap? Or 1:9 UNUN would also do 
the trick I guess. But that would need to be switched in and out.

Thanks,

Jussi (AA6KJ)


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