Millen air variable IF transformer

[N4LTA]

Anyone have an old junker Millen 62454 IF transformer or similar?

I just finished a replica receiver from the 1942 ARRL handbook and was aligning it last night. Things were going well until one of the air variables would not tune and was very noisy. I took it apart and found that the hex end (tuning end) has a small crack. It turns out that the hex end is not a nut but is press fit and holds tension on a flat spring that keeps the rotor in the proper position. With this loose, the rotor and stator touch.

The cracked piece is a slice of hex shaped brass with a hole that press fits to the tuning shaft. It will not be easy to make or find one.

Any ideas will be greatly appreciated as I don't have any source for new transformers and to use something different will cobble up the receiver.

Thanks

Pat
n4LTA

[W3GMS]

Pat,
Can you send me a picture of the small air variable cap you need?  I have lots of very small air variable that were made by Johnson years ago and we may be able to match you up with something that would work...
Just a thought.
Joe, W3GMS
josephfell@verizon.net 

[KB3DKS]

Pat,
If Joe doesn't have the correct one send me a pix and possibly the C value since I have quite a few myself.
 Recently when bringing an old BC-312 back to life I found several of the trimmers in the RF and IF boxes had done the same thing which resulted in toasted plate resistors in those circuits.
These trimmers had circular press fit bushings instead of the hex but are otherwise the same and what I did rather than the difficult removal of the the boxes themselves was to use a #33 or so drill bit and pin vise extention in a Dremel tool to drill a small hole in the trimmer shaft and using a small nail and a couple small washers was able to respace the trimmers.
You don't need to go to that extreme with yours but for future reference...

Bill KB3DKS in 1 Land
doxemf@aol.com

[N4LTA]

Well I was sitting at work today and thought of a solution. I used to do some model airplane work and remembered the bushings that hold the wheels on the axles. These are brass bushings with a steel allen type set screw. I came home at lunch and found that I had a package of 1/8" bore. They were close but didn't fit. I thought about boring one of them in my mini lathe but then I found a brand new package of 5/32" ones. They were a perfect fit. I slipped one on and using finger pressure set the gap in the capacitor and tightened the set screw - It was near perfect - Hooked up the ohmeter to make sure there was no short across the whole range.

It was a good day on several fronts. I received an email from Gary at Playthings of the past - he had another IF can - One more only. So - I got the installed one repaired and now have a spare.

One last thing though - these things have a fairly large silver mica cap on each side. I hear that many are bad and should be replaced. It is easy to do - but they seem ok - but I wonder if they have degraded and a new modern silver mica would be better?

I'll still take a picture if anyone wants to see what I was talking about. Thanks everyone for your answers.

Pat
N4LTA

[W3GMS]

Pat,
Glad you found a solution.  Looks like your all set now.  While you have the assembly apart, if it was mine, I would replace the old silver mica cap.  My luck usually would have it fail a few weeks after I got it all back together! 
Regards,
Joe, W3GMS