Hello LF'ers,
After an expensive accident whereby my home brew antenna change over
relay put nearly a kW of RF up the RX antenna jack of my Kenwood
TS-590 i want to safely long term test the relay. It may have been my
lack of foresight in using two identical N type sockets for the amp
input and the antenna on the relay box and they got reversed...The
relay is a Russian
http://qro-parts.com/product_info.php?products_id=102
It needs 24V to reliably change, that is sourced from 12V via a DC to
DC converter that is energised via a safely long delay from my U3S
exciter so TX is delayed 100mS It's connected like this:
The output of my 1 kW amplifier to NO connection and receiver to NC
connection of the same relay, with COM port to antenna), then
de-energized I'd always be in RX mode and energized I'd be in TX mode
and there's no way the TX should ever be connected to the RX no
matter what failed. (Theoretically! I am not sure what reversing the
amp and antenna connections may have caused, but I am concerned some
other issue caused the RF to appear on the RX port....) I don't think
the pre LPF voltages from the amp would be too high for this relay,
but can't be 1005 sure of this given what occurred. In any case
there's also a 40 Amp 24V automotive "safety relay" that grounds the RX
output jack
when in TX mode. The failure of this to protect the TS-590 further
suggests I might have had the antenna and amplifier connectors
reversed, although it all worked fine until the early hours when the
WSPR spots ceased and I found the bad news.
Anyway, I need a "something" to put across the RX antenna output BNC
socket that wil blow or somehow tell tale if RF is injected there. I
don't have a high power enough dummy load other than a huge water
cooled 10kW Bird one which means flowing mains water through it to an
outside gutter overnight or longer. My none water cooled one won't
take high power for long at all. If a FET blows in the amp I can
swallow that, rather than my current Red Pitaya receiver getting RF up
it :) So what could I put across the jack instead of a receiver that
will tell tale anything nasty happening during a prolonged test
please? Thanks.
--
Best regards,
Chris mailto:[email protected]
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