[Elecraft] K3: 'LineOut' problem/question

[Randy Cook]

Problem: Very low to no output on K3 line out jack (for PSK31 use)

I am trying to get PSK31 running on my MacbookAir with Cocomodem (through a iMic, to USB port). It has run before, several years ago. I follow K3 manual setup and find the output level is very low. On Cocomodem waterfall, I can see very, very weak signals, could just be noise. I am in Data mode, Data A set. I adjust LIN OUT in Config to maximum, a very slight change in waterfall level. I tried plugging in headphones into the Line out jack to see if there was any change. I hear nothing. I also swapped out my MacbookAir for an iMac desktop, with no change in the problem.

To check everything else, I switched cable from Line out jack to Headphones jack, and change the LIN OUT in Config Menu to ‘Headphones’ per the manual. Use same cable and iMic as before. Now, I get signals on the waterfall, and can decode many in CocoModem. So, everything works except the K3 Line out signal.

Per tech support, I download schematics and I remove Audio out board to check the chokes, L1 and L2. Read about 4ohms, as do all the similar chokes on the board. Working backwards, I check the transformer that feed the in and out line. T1 and T2 read about 55 ohms on the secondary, seems about right. 

I did swap out the audio jack board for a replacement from Electraft, thinking it could be a jack problem. No change. Am I missing something simple here? A Menu setting?  If not, next troubleshooting steps? 

OK to email direct instead of posting. 

73

Randy - K6CRC
k6crcus at gmail.com <mailto:k6crcus at gmail.com>