Re: {Collins} Cleaning (transmitter) variable caps



On Nov 2, 2014, at 4:05 PM, Mark Pilant <n1vqw@xxxxxxxx> wrote:

> I spent some time starting to clean up the KWM-2 I recently picked up, ...
> I'm wondering if there are any good ways, short of "dunking" the entire
> chassis, to clean these in place. 

Mark,

Do not “dunk” it:

One method favored by some experienced Collins restorers is this:

Use 50-50 mixture of 409 and household ammonia.
(VERY strong - use outside only!)

Remove meters and any dials that may be subject to water.
(in the KWM-2 this would involve considerable dis-assembly!)

Seal transformers such as IF transformers with blue painters tape or the like.

Spray whole radio with spray bottle and 50-50 solution, use paint brushed to get dirt off.

Use PLENTY of wash/rinse water, preferably warm.

Dry radio in warmth  such as Arizona sun in the summer*, or with clamp-on reflector lamps at short distance with fan(s) to get lots of air circulation.  Do not rush the drying process.

*Consider a trip to  dry location in the southern hemisphere where it is now summer.

Follow above treatment with re-assembly, lubrication, and complete alignment.

NOTE:  Bill Carns has warned against using such harsh chemical cleaners on Collins radios, so do be advised that although this method would get you a like-new looking radio, it may set it up for later corrosion and other troubles later in its life,

If you extract the tuning cap(s) and possibly final tank coil(s) for cleaning outside the chassis, put them in the dishwasher for one cycle.  Then very carefully re-lubricate and re-install.

Roy



Roy Morgan
RoyMorgan@xxxxxxxxxxxx
K1LKY Since 1958




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