Re: burst of harmonics during CW key-down?

Joe Puma

Yes search for carrier burst in the threads and you’ll find your answer. I just did the mod on mine. I also noticed that if you have RF issues in the rig it will show a power surge in meter and you might hear some RF noise in speaker during the delay time of a CW unkey. I was getting RF in the pan adapter wire I installed. 


On Apr 17, 2019, at 5:27 PM, Adrian Chadd <adrian@...> wrote:


I've noticed on my ubitx4 that when you key down for the first CW tone (when it transitions RX->TX and transmits a tone) I get some pretty hefty harmonics out before it settles down. Subsequent CW tones whilst TX is asserted is fine.

It shows up on an LED SWR meter as a quick, bright flicker before it settles in OK.

I'm running the stock firmware with a couple of other bugfixes (like changing LSB<->USB doesn't immediately reprogram in the correct VFO until you change frequency..)

Has anyone else seen this? Is this fixed in Ian's firmware? (I checked out the source code and I can't see anything obviously fixing TX<->RX timing or the order which oscillators are gated/programmed.) Or should I go and dig into it a bit myself?



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