[Elecraft] New KPA100 no receive on SO239

[Catherine James]

I have largely completed building my KPA100, and reached the point in testing where the speaker works if connected to the base K2 with the signal coming in through the BNC antenna port.

However, I have been unable to hear anything when the antenna is connected to the KPA100's SO239 antenna port.  On 40m, I had a strong signal coming in on a different receiver, but switching the same antenna to the K2/100 produced silence.  (Because of lack of signals on other bands lately, I cannot do a good receive test on other bands.  The K2 receiver is too quiet to use normal band noise for a good test!  I may have to create my own QRP signal from a different transmitter into a dummy load to have a signal to listen for.)

I have traced DC continuity from the RF Aux pin on the KPA100 board to TP2 and TP3. I have also traced DC continuity from the center pin of the SO239 to T4-6, T4-5, and C1.  I also appear to have DC continuity between L4, L5, and L6.

Are K5 and K6 latching relays?  Should I have DC continuity from RF Aux RFIN all the way to J2, going through the low-pass filter of the band most recently selected?  Or do K5 and K6 open on all bands when power is off?

What should I check next?

73,
Cathy
N5WVR