I suggest resoldering the connections to the frequency determining
components. If there are any mechanical linkages or bearings, those could
be needing some cleaning and/or lubrication. Especially look for wiping
contacts that could have a thin film of corrosion.

If it's permeability tuned, there are no wiping contacts. But the slug
could be loose or dirty.

Look for cracks in capacitors that could cause capacitance jump with
temperature or movement.

Measure the supply voltage on the oscillator; if it changes when the shift
occurs, the trouble could be caused by a zener diode.

I could go on, but you get the drift. (that;s a pun)

73, Bob

Clean the switch contacts for the RIT control. Or at least cycle it rapidly
several times and the problem will go away.

--
Clif Holland, KA5IPF
AVVid
Authorized Kenwood and Icom Service Center
816 W Shady Grove Rd
Irving, TX 75060

www.avvid.com

1-800-214-5779
972-870-0630 (Local)
"tlee" wrote in message ...
I recently bought a TS-120S that every so often will just jump 4-8khz off
frequency without touching knob. This is not a gradual drift but a direct
jump. I have removed the VFO and removed VFO shell case and tightened all
screw backup as suggested in kenwood service bulletins, but it is still
doing this. Any ideas or help would be appreciated from the technical
people out there. 73 Ted N8GPQ