Re: {Collins} Trimmer Capacitors



I 'd like to chime in with regard to stuck trimmer capacitors used on Collins and many other gear of the day - would not always be successfully made adjustable by freeing the slotted shaft. You could turn the shaft but not successfully change  capacitance. The move able part and fixed part are a bit more complex in their assembly and depending on which part of the multi layer component is stuck.

Either disassembly cleaning and freeing all pieces, or other tricks such as applying a small amount of heat to the shaft without removal and disassembly was the only successful way of restoring adjustment.

Further using a screw driver on a capacitor where both sides are off of chassis ground would result in constant cut and try to have the same result after removing the screw driver due to Distributed Capacitance from the screw driver shaft.

So this caused me to search for those good old alignment tools with a plastic shaft and a tiny blade in the end such that the plastic shaft fit over the capacitor shaft when the alignment tool blade was aligned with the slot in the shaft.

Much to my surprise I found a complete new kit of these alignment tools available (around 8-10 tools as I recall) from LKG Philmore. These folks supply independent electronics stores across the US (yes still some of them left).  Their web site has referrals to dealers that may have these available. I actually found them first on eBay then ordered them from LKG with an order I do on a routine basis.

In the event you don't I have the ability to purchase these directly from an LKG dealer stocking them, it is possible that I could make these available if enough of the CCA group are interested. 

It honestly only makes sense to do this as a group buy in order to keep shipping cost a minor part of the transaction with LKG.  That benefits everyone. As is often the case shipping can be as much of more than the scarce part you are finally obtaining.

I currently purchase a few parts directly from LKG as an OEM.

Dave WI6R
Sent from my iPhone

On Oct 25, 2017, at 9:03 AM, Michael Tortorella via Collins <collins@xxxxxxxxxxxxx> wrote:

Hi everyone, I would like to share an idea for a simple tuning tool I made
for the trimmer caps in the S/Line.  It lets you grasp the entire square
instead of using a screwdriver in the slot.  I thought this would help me
avoid any mistakes or damage due to my clumsiness.  The tool is made from a
small piece of 1/8" square brass tubing attached to a small screwdriver.
You might have to gently file the inside of the brass tubing just a little
bit to fit over the square, this is easily done with a small needle file.
It is much easier to see this with a picture, so if anyone is interested I
am glad to send 2 pictures showing the construction.  I know this tool is
not absolutely necessary and we all have been getting perfectly good results
for over 50 years using just a screwdriver, but I hope this may help someone
who may need to loosen (gently!) a stuck trimmer or is afraid of clumsy
mistakes like I make.  Thanks for the BW and 73, Mike W2IY

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