Jerry wrote:
"ve2pid" wrote in message
...
Seems to me, that relay should always be closed during operation
from the base feedpoint so there will essentially be zero volts
across the contacts. Since the relay should not be switched
with the key down, your question seems irrelevant.
To be more precise, the loop would remain intact, but I want to
disconnect the coax from the inactive source, and I am looking for a
way to do this using a relay near the source (or at the shack). The
power would the full legal power.

Any idea ?

Hi Pierre

I submit that you will have no luck with your plan to run the two
transmission lines from the antenna to the shack where the switch chooses
which one to use. The unused line will present an impedance across the
"gap" which is a function of the length of the line.
Correct me if I am wrong.

Jerry KD6JDJ

One can hook a DPDT relay up. Armature terminals go to the loop. One set
of the contacts are shorted, the other set connect to the feedline.

Yes, you'll need to know the voltage (relative to ground/feedline/relay
coil) at that point to choose a relay. Hook a large value resistor in
your NEC model from the point to "ground" (you should be modeling that
piece of coax as a single wire anyway.. so just put it in series). not
much current will flow through the resistor, so the pattern won't
change, but you'll be able to measure the voltage across it (or, more
properly, you can look at the current in that resistive segment and use
Ohm's law)