[Milsurplus] TR switches

[Bill Cromwell]

mac wrote:

My experience with a commercial vacuum tube TR switch (Johnson as I  
recall) was that  any strong BC station operating nearby would result  
in a multitude of annoying  intermod products spewing out of  the unit.

Dennis D. W7QHO
Glendale, CA

I have one of those units that I have doubts about using. They are
intended to be connected external to the transmitter and receiver.
Reading about other people's experiences with that kind of lashup
indicates the kind of problems you are describing. Even a low pass
filter between that T/R switch and the antenna was apparently inadequate
sometimes. There were hints about the effectiveness of the rf grounding
and the bonding of the station chassis grounds. That's why I chose the
scheme I did.

I have to say that I did not have a blowtorch broadcast station any
closer than 125 miles away (WJR Detroit). The local broadcasters were of
the 5000 watt variety (or less) and the nearest was still 12 miles away.

73,

Bill  KU8H