[Elecraft] {OT} - Variation on use of a coaxial switch (stan levandowski)

[Richard Fjeld]

This sounds the same, and I made it to protect the front end of each 
radio by switching the radio not being tested to my dummy load in case 
one of the radios should transmit. I intended my switch for receive 
comparisons.  I am surprised the commercial switches can handle a 
kilowatt and provide adequate isolation.  I wouldn't want to use that 
kind of power with the switch I made.

I didn't know about the switches you mention.  I thought there should be 
a need for them, so I called MFJ.  I like to protect my equipment. I 
know guys who don't think this way. Maybe MFJ didn't sell any and 
discontinued them. At the time, I thought they described them rather 
vaguely, missing the whole purpose.  Maybe I haven't found them on their 
website now.

Dick, n0ce


On 1/2/2017 7:06 AM, Charlie T, K3ICH wrote:
> Several companies (Bird, Transco) make what you describe.  It is a four
> terminal coax relay called a "Transfer Switch" that for example, connects
> any two antennas to any two radios, but never at the same time.  In other
> words, radio A connects to antenna 1, and at the same time, radio B connects
> to antenna 2.  Activating the switch ( either mechanical or electrically
> activated) changes the condition for A to 2 and B to 1.  Most are good for a
> kilowatt well up into the UHF ranges.   For HF, I made one using a heavy
> DPDT relay.
>
> 73 Charlie k3ICH
>
>