[Kenwood] TS850- another symptom...

[Henry]

The saga continues. I've found out that in tune position, the power output
starts out good, then drops about 10 watts for about a second, then up
again- like
a pulse. It does it on all bands.
I tried modulating the rig in ssb, and it seems like it does it there too,
but am not sure. Does this symptom sound familair to anyone? 
Getting to the end of my patience rope- the packing box is coming out of
the basement today- 
73,
Henry, W2DZO