Hi friends,
I'm continuing to make slow, but steady progress on the homebrew SBITX.? ?The most recent issue resolved was self-oscillation in the WM8731 codec on CW key down.? You could hear the CW sidetone in the speaker but with lots of distortion - also visible in the RF.? The fix to that was to swap out the MIKROE codec board.? The new board did not exhibit that problem.? ?But I have an ogoing problem wiht intermittent Tx which was happening on either board.
The issue is this.? On CW keydown one of four things happens:
1. Nominal case - I hear audio out from the speaker and see RF all the way through to the antenna.? All is well.
2. Audio only - no RF.? that means one output channel of the DAC getting signal but the other is not,
3. No audio and no RF,? the rig goes into transmit - you can see it on the SBITX spectrumb -? but nothing comes out either DAC port
4. RF but no audio - this has happened only once or twice
demonstrating what I am talking about.
Has anyone experienced anything similar???
73,
Dean
KK4DAS
