Ray,

For what it's worth, I've been running a homebrew solid-state QSK CW 
transmitter for the past 4 years. My T/R relay is an AXICOM V23105A5303A201. It 
is a dual SPDT relay where each SPDT section is tied in parallel for greater 
power handling capability. The receiver is connected to the antenna through the 
relay on receive, and is allowed to "float" as an open-circuit on transmit.

The relay is controlled through timing and logic circuitry so that it becomes 
energized before any RF is produced, and de-energized after the RF envelope has 
decayed to zero. While I own a K2/100, I have been using this transmitter with 
either a Drake 2C or R4C receiver until I homebrew my own.

I just ran an experiment where I terminated the RCVE port with a 50 ohm load 
and measured the RF voltage across the load with a scope. On 40 meters where my 
transmitter produces 64 watts, I measured about 0.8v p-p across the terminated 
RCVE port, or about 1.6 mW (2 dBm) of RF. That equates to 46 dB of isolation at 
7 MHz. This seems consistent with the isolation specs on the relay that can be 
found here: https://www.farnell.com/datasheets/1918250.pdf.

The Drake receivers handle this signal level with ease, but I haven't tried the 
K2.

Incidentally, Jim, W6PQL has additional information on using inexpensive relays 
in RF circuits at his website: 
https://www.w6pql.com/using_inexpensive_relays.htm


73 de John, KD2BD
  
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected] 

Reply via email to