I also had this problem. I had a pretty big spike on keying the mic
and also a smaller one on release. Nulling the carrier was the
solution (actually it didn't make the spikes go away completely but it
did reduce them quite a bit) but it is tricky. You have to go back
and forth between LSB and USB to get a good null for each sideband.
On a stock Omni VI, the cxr null pot is a single turn component. This
makes the null extremely sharp and frankly, in my case at least,
getting a good one was almost impossible. In the past, some hams
have reported good results from replacing the stock single turn with a
multi-turn trimpot. They are easily available from Mouser. They make
the null a lot wider and easier to get into the minimal sweet spot. I
have not done this because I only use mine on CW now so I am only
reporting what I have heard from others.
Rob / K5UJ
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