[Elecraft] K3 keying an amplifier

[Scott Ellington]

You might have a problem when only one rig is powered up, with the unpowered one pulling down the key/control line.   The K3 is OK, as both outputs are open drain/collector.  If that's also the case with the ICOM, the "Y" connector should work.  If the ICOM has a pull-up resistor, or anything except an open drain/collector connected to that control line, there could be a problem.

Scott  K9MA 


On Feb 16, 2011, at 1:29 PM, Fred Serota wrote:

> Is there anything about the voltage or current on the keying line that would prohibit putting the K3's key line in parallel with an ICOM's keying line so I would not have to switch between the two when sharing an amplifier?
> 
> In other words, could I just use a "Y" connector to connect the two transceivers to the keying line on my amplifier (Alpha 9500)?
> 
> Thanks in advance,
> Fred, K3BHX
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Scott Ellington
Madison, Wisconsin
USA