Topband: CLARIFICATION: Help Needed Decoupling the TX Antenna

[Herb Schoenbohm]

Eric Rosenberg wrote:
> Some points of clarification:
> -
>
> FWIW, I have an unused Dow-Key microwave SPDT relay. Big and beefy.  Can 
> this take the place of a vacuum relay?
>
>
>   

Eric, most microwave relays won't take HV that exists between an open 
wire in a normally resonant Marconi where reactances, current and 
voltages are excessive depending on the power you run and the design 
they are.  Before you go out an buy vac relays you might see where a 
manual opening or a grounding of the TX wire antenna makes any 
difference on your RX antennas. I would think that as an alternative to 
a vacuum replay that a bunch of automotive 20 amp relays in series may 
give you the voltage rating for several hundred watts maybe more.  I 
would suggest however that the coils (and they would be all common 
connected) would have a series of RFC chokes so each coil is isolated 
from each other coil at RF.  Never tried this....it sounds to easy but 
could work.  I have a huge 5 KW porcelain RF transfer switch  and your 
are welcome to it........but by the time it takes the contacts to flip 
you would have missed your call and signal report!


Herb Schoenbohm, KV4FZ