I have a TS-520S that works reasonably well on VOX. However, when
using PTT or if I use the "Send" switch to go to the transmit mode,
the TX audio or RF chain is inhibited from producing very much output
for several seconds. It is like large cutoff bias glitch is being
applied somewhere and has to leak off to allow the TX audio/RF to get
through to the output stage. As the cutoff bias leaks off slowly the
transmit output slowly rises up to normal levels. This takes several
seconds.

I sometimes even see this while operating VOX but this is fairly rare.
However, I am always seeing it if I try PTT.

I've looked through the schematic and see no particular reason for
this. The PTT or Send switch appears to just manually activate one of
the stages in the VOX circuit.

Anyone ever see anything like this on a TS-520S?

Curtis Eickerman