[Elecraft] K2 KSB2

[Don Wilhelm]

Scott,

U1 pin 21 has nothing to do with keying on SSB.  The signal line you are 
looking for is /PTT on the KSB2 or on the main K2 the /DOT-PTT signal.

The problem can be with your microphone configuration header wiring, 
your microphone, or a fault on the KSB2 board.
One quick check is to plug a key into the K2, set SSB mode and close the 
DOT paddle.  The K2 should go into transmit  There will be no RF until 
you feed audio into the KSB2, but you can check that it is set to 
transmit by checking the voltage at the anode of RF Board D6 and D7.  If 
the K2 is set for transmit, the voltage at D7 anode will be near 8 volts 
and the voltage at D6 anode will be near zero..  If it does that, you 
have a problem with the PTT line from the microphone, or the microphone 
configuration header wiring.

73,
Don W3FPR

wsm at amaonline.com wrote:
> Hello
> I just finished building the ksb2 ssb adapter for my k2 and am
> having a problem with it. It will not key the k2 in ssb mode.
> All the test and alignment went as they should, and the voltages
> on all components are what they should be except for one. On U1 the
> voltage on pin 21 is 1.2 volts instead of the called for 5.8.
> Am using a new Icom HM-36 mic and it is wired as the manual says.
> Does pin 21 of U1 having anything to do with the keying on ssb?
> Any info will be appreciated.
> Scott
>   
>