"Tom Tillander" wrote in message
...
My Kenwood TS440S is beginning to present symptoms (frequency drift and
intermittent dots in the display) of PLL unlock. Service Bulletins at
Kenwood.net suggest that replacing a fist full of diodes with new diodes of
any of these types : 1S2588,1SS91S, BA282 will cure the problem.
Additionally, I have heard that 1S1587 diodes can be used. However, I have
been unable to find a source for these parts that will send or sell me just
a fist full. I haven't tracked down the manufactures of all the parts.
However, the BA282 seem to be made by Vishay.

Can any of you recommend a supplier for any of these parts? Thanks







Hi Tom,

I have a TS-940 that had the same problem (freq.drift, blank display).
Was a problem on the PLL board. If I tapped/slapped the top of the transceiver or
tap the PLL board, it would also cause the rig to jump off freq., warble or make
the display go blank. It was caused by several broken solder joints on the bottom
side of the PLL board. Using a magnifying glass I found "rings" around the
component leads on the solder joints which were solder fractures. This has
happended twice on my rig, both on very hot days. Now I avoid operating the
rig when it gets hot in the shack (90-100 degrees) and have not had the problem
since. Have owned the 940 for 13yrs now.
You may want to inspect the solder joints on that board with a magnifying glass
before replacing parts.

Good luck on fixing your rig
Tom