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Alignment tool for Philco 70A trimmer capacitors
#1

Gents,

I need an alignment non-metallic tool (hex nut driver type) in order to fine-tune the trimmer capacitors on my Philco 70A.

Where would I find such specific alignment tool ?

Your help in this matter is greatly appreciated..

Regards


Récepteur
#2

Use a plastic 3/8" diam. piece of tubing (hobby or craft shops) and heat up a 1/4" hex nut to "melt-in" an impression of the nut in one or both of the open ends.
#3

Mr Schwark,

Thanks for the valuable trick.

Regards


Récepteur
#4

Mr. Schwark was my Dad.

I'm just Chuck, mon ami. Icon_biggrin
#5

Chuck,

Merci !

Récepteur
#6

Chuck Schwark Wrote:Use a plastic 3/8" diam. piece of tubing (hobby or craft shops) and heat up a 1/4" hex nut to "melt-in" an impression of the nut in one or both of the open ends.

This may be an incredibly stupid question, but I don't ask I will never
know. Does the nut stay in the piece of tubing this grabbing onto the shall we call it male nut sticking out of the radio? It sounds to me like it does. What I'm picturing is something that has to grab onto the screw like device sticking out of the radio and turn this. Is this correct or ??

73 de,

Gary/N9VU
#7

The adjustments are 1/4" hex nuts in the older Philco IF cans and the compensator padders and trimmers - not screws.

Take a run-of-the-mill 6-32, 1/4" hex nut thread a long-ish screw into the nut before heating to allow pushing into the tubing end and removing after cooling off.

You are essentially making a plastic nut-driver. The original was harder phenolic, but the plastic will do fine.

Here's what an original "Philco Alignment Tool" (left) looks like:

[Image: http://www.philcorepairbench.com/images/...ools02.jpg]
[Image: http://www.philcorepairbench.com/images/...ools01.jpg]
#8

reviving a very old thread.

I'm messing with using 1/4" PEX (used for plumbing out here, about $1.60 for 4' here in vegas at lowes.)

My addition to the whole thing is instead of using a nut to put the hex into the tubing, I'm using a 1/4" allen wrench. using the long arm of the allen wrench gives you a 3" long 1/4" shank to drive into the tool, and the short arm makes for a good handle while working making the tool.

I'm trying to find a good way to heat the PEX instead of the tool to make it easier to form the tool.

John
Las Vegas, NV USA
#9

Hi Guys
I just use a cheap BIC pen with the innards out of it. That and a little heat from a heat gun over the adjusting nut. I do like allen wrench idea too. Also a tiny speck of oil on the screw to help it turn easier isn't a bad thing.
GL
Terry

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#10

Alignment Tool:
Here's another way to make an alignment tool for those pesky 1/4" nut compensator/trimmer  caps.  

Take a 1/2" wooden dowel and place a NYLON 5/16 - 18x1 Socket Head Cap Screw (Grainger item# 4FVF8 ) into one end of the dowel.  I just used epoxy to hold the screw into a hole drilled in the end of the dowel.   You also need to drill a few millimeters into the socket head with a 3/16" bit to allow room for driver to fit onto the nut.  Instead of a wooden dowel  you can also use some PVC tubing for the handle.  They are not pretty but it works.  Here are a few pics:

[Image: https://www.dropbox.com/s/075uq35qxdnoh2....jpg?raw=1]
[Image: https://www.dropbox.com/s/bqbv7mu4r401u8....jpg?raw=1]
[Image: https://www.dropbox.com/s/kwtmlgx08bk0d5....jpg?raw=1]
#11

Nicely done. I just wrapped some electrical tape around a steel nut driver on a recent Philco 60 alignment. While it prevented shorts to the chassis (some of those trimmers are hot!), the metal did affect the capacitance a bit. I compensated by tweaking the trimmer past the peak and checked the result one the tool was removed. It would certainly be easier with a non-conductive tool like you made Icon_thumbup
#12

The business end if that tool appears to be a nylon capscrew. Add that to a piece of dowel, and PRESTO: Alignment tool! Careful drilling the center of the cap screw. The threaded part the alignment cap rides on come out of the center of the nut.
#13

Yep, as mentioned in the post its a NYLON 5/16 - 18x1 Socket Head Cap Screw (Grainger item# 4FVF8 ), you only need to drill out a millimeter or so in the center of the cap screw head.
#14

Sets like the Philco model 45 'butterfly' require a 1/4" nut driver to adjust the compression style trimmers in the IF cans, but the clearance into the top of the cans is very, very narrow. I got away with a recent alingment on my model 45 by doing this melt-forming trick with a very thin piece of plastic tubing, but I had to cut off and remake the nut-end after each can, as the plastic didn't hold up well in use. Basically, it was a single-use tool. Sombody needs to make a really high quality, thin-walled example of this tool from a material that's got some durability.
#15

There is a member making a tool but I'm not sure how thick the outside edge is. He uses a nylon 1/4 cap head bolt and a plastic tube. I could use a thin walled one too as my old HRO has a similar arrangement. The trimmers a very tight so the bp pen doesn't cut it. I generally find the Philco trimmers once loosened w/nut driver not difficult to manipulate w/ bp pen.

GL

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry




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