[Kenwood] TS830 Drifting

[peter markavage]

There was a service bulletin highlighting this problem of frequency
hopping.
Pete, wa2cwa
ManualMan, now has available laminated credit card style "Quick Reference
Guides" and laminated "Mini-Manuals" for many of the current Icom,
Kenwood, and Yaesu HT's,mobiles, and HF rigs. Newly introduced heavy
steel HT stands are now available.


Service Bulletin no. 840 (14-4-1982)
Some users may report an intermittent shift in the display and operating
frequency. This may typically be a 1 to 4 kHz random shift. Cause will be
a loose grounding screw on the AF/AVR unit heat sink. 
On the AF/AVR unit X49-1140-00, there are three self-tapping screws
holding the aluminum heat sink to the PCB. These also supply the ground
connection to that section of the board. Between the heat shink and PCB
foil, add a toothe-lockwasher N17-1030-41 at eht two self-tapping screws
on the side of the heatsink that has the two transistors attached. (The
remaining screw already has a lock washer.)
When replacing the board to the chassis, add a solder lug E23-0420-05 to
the heat sink mounting screw as shown, and tighten all screws for this
board. Solder an insulated lead between the TPG (Test Point Ground) wrap
post adjacent to C81, and the added solder lug. 
Procedure: 
Remove the top cover (8 screws) and unplug the speaker.

Remove the bottom cover (8 screws).

Remove 5 screws holding the AF/AVR unit and swing the board over. Leads
do not have to be unplugged.

Add two tooth-lock washer as shown.

Replace the circuit board and heat sink to the chassis, adding the solder
lug as shown.

Solder a jumper between the TPG wrap post and the added solder lug.

Replace the top and bottom covers. 
On Mon, 6 Dec 2004 14:10:17 -0600 "Jim Roughley"
<JVROUGHLEY at COX-INTERNET.COM> writes:
> My TS830 has a problem with the frequency jumping around. The problem 
> seems to be occurring when the HV is turned on and
> when it's turned off. I have re-seated the connectors on all the 
> PWB's and used deox on the connectors. The fault is intermittent and 
> is really bad on 28 MHZ but it will also do it on the other bands, 
> but not as bad. Any suggestions on how to fix this problem would be 
> greatly appreciated.
> Thanks,
> Jim Roughley, K5JUC