[Elecraft] [K3] splitting RS232 output for 2 serial ports

[Don Wilhelm]

John,

The "no frills" one transistor circuit can be found at 
http://www.aa5au.com/rttyinterface.html
If you want to add a series resistor and a diode to protect the 
transistor from negative voltage excursions,  take a look at the circuit 
for PTT in http://www.qsl.net/w/wm2u/psk31.html.
There are also optocoupler solutions that do the same function.

73,
Don W3FPR

On 8/7/2012 6:27 PM, John Shadle wrote:
> Thanks, Don. Are you talking about the "PTT IN" and "KEY OUT" RCA jacks?
>
> I Googled "one transistor keying circuit" and it came back with some
> amplifier keying circuits. Is that what I should be looking for, or
> something else? I'm sure the answer is obvious, but I'm just having a
> hard time seeing it. ;-)
>
> Take care.
> -john W4PAH
>