[Elecraft] K3 Push to Talk Circuit

[k7hbg @dslextreme.com]

Hi Everybody;

 Since K3 technology is spoken here, I'd like to pose the following
question.
 What is the maximum resistance on the K3 "PTT" keying line that will
activate this function?

 A resistor at the front panel "MIC" plug, between  PTT (pin 2) and ground (
pin 7) to activate the "PTT" function.
I couldn't find any info in the manual and so thought I'd bring my request
here.

Best regards to all. Bob K7HBG