[Elecraft] adjacent antennas and potential radio damage

Mike Harris mike.harris at horizon.co.fk
Wed Apr 16 13:08:35 EDT 2014


Quite so.

Forty years ago the FT101 had a front end protection circuit that 
included a light bulb.  When I was in the Antarctic, location doesn't 
really matter, my antennas were reasonably close and when I keyed the 
main TX at 1500W the rear of the '101 would flash with the keying. 
Never suffered a front end failure.

I have a circuit diagram dated 2010 for an "RX Protector", which 
unfortunately doesn't offer any authorship detail, it looks similar to 
the '101 circuit.  If anyone wants a copy let me know.

If the idea of a bulb and a couple of back to back diodes and big 
signals worries you then perhaps making this as a piece of test 
equipment to be used as a level reality check and then taken out of the 
signal path is possibly the answer.

Regards,

Mike VP8NO

On 16/04/2014 12:40, Charlie T, K3ICH wrote:
> Connect a "grain-of-wheat" light bulb across the unused coax and
> gradually increase transmit power.


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