I apologize if this subject has been discussed here recently but I am not a
regular subscriber. I have a Kenwood TS-940, bought in 1989. The memory
and timer functions work okay but I have been told that the lithium
batteries
used in these circuits could leak and damage if not replaced after so many
years. Is this a real threat? If so, is it a lot of work? Appreciate
comments

I haven't heard of problems with lithium batteries leaking. That's a
problem most usually ascribed to alkaline batteries, whose outer
jackets can corrode as a result of the electrochemical reactions
within the battery. However, your rig's battery may well be reaching
the end of its use-life in this application - 10 years is the usual
quoted range for low-power memory backup applications - and you may
wish to consider replacing it for that reason.

Replacing the battery may be either easy, or tricky, depending on the
rig... I don't know about the TS-940. In some radios the battery is
in a clip holder, and replacing it is trivially easy. In most radios,
the battery is soldered into place, and it's necessary to unsolder it
and solder in a new one - the usual static-discharge and
don't-burn-up-the-board precautions should be taken. You'll probably
find that your local Radio Shack will _not_ have a replacement battery
with the same sort of solder tabs - you could either order the right
battery from (e.g.) Digi-Key, or remove the old battery and solder in
a battery holder (if you can find one which will fit), or improvise
(attach lead wires to a lithium coin battery using a dab of
silver-loaded conductive epoxy).

In some radios, the battery provides backup power not only for the
programming, but also for the radio firmware. Replacing the battery
in these radios is tricky - in order to avoid losing the firmware
you must jumper in an alternative DC power source when replacing the
battery, or you must have the specialized kit needed to reprogram the
firmware after replacing the battery. This is usually a job for a
factory or factory-authorized service depot.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
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