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Philco Shadowgraph meter, the old style, coil removal
#1

Since no one answered that question in my Philco 18 thread, I will make it a separate issue.

My Philco meter has a bad coil. Needs to be rewound. bad in itself, ain't it.
What exacerbates it is the fact that the coil's core bar going through it is pressed in the rest of the core.
I am not sure how to extract it. There are no rivets/screws etc. It is just pressed in, and it is a reversed wedge so it won't just come out.

Anyone has experience with these kinds of tsuris in the tukhes?
#2

Oh! C'mon! Once in a blue moon I am having a problem and everyone is as silent as fish!Icon_lol

Now, I've extracted the dang bobbin. Just needed to think a bit.

Now there is a simpler but insurmountable for me problem: winding few thousand turns of #40 wire (and taking the old one off first). And I need to buy it first.

Q: Does anyone know anyone(s) who rewinds bobbins? Small bobbins with thin wire with huge number of turns. I dread this. That is since I was 8 years old and started tinkering with electronics, the coil winding business was the sole part of it that made me shudder. In a nutshell, I hate it. I probably hate it as much as writing documents. Actually I hate it more. I write docs habitually.

I could use some help in that department. For a fee, of course.
#3

I would say not too many folks have experience in rewinding shadowmeter coils, let alone knowing how to remove the coils from the various versions of these.

I tried rewinding one once. I didn't have any 40 gauge wire so I used 38. Big mistake. The thing sort of worked afterwards, but the deflection of the vane was poor.

Something like this would best be wound with a coil winder, I think.

--
Ron Ramirez
Ferdinand IN
#4

Well yeah, that figures. The only problem is, I don't own one. And I am not crazy about making one myself like that guy did on a youtube video. To buy one...possible, not sure though which one I need and if it makes sense financially; aftef all there are only so many coils left for me to wind in my life, considering I wound maybe 3 in my whole life. I would rather find someone who does it.
#5

I've wound hundreds of thousands of loops of coil, by hand. Small wire. Just for the fun of it (and other such nonsense). Not exactly for this this intent and purpose, though. My lifeforce grows week these days to boot, so not sure if I could do anything so intricate anymore. Wish I could help. Good luck to you, and hope you find your muse.Icon_e_ugeek
#6

I've been kind of busy lately, here is how I did it. It worked, but the deflection was about 75% which is better then nothing.

http://philcoradio.com/phorum/showthread.php?tid=4811

I used a 100 rpm reversible gearmotor from grainger to wind it. The shaft was the exact size needed for the bobbin and if it was stuffed in a box somewhere I would pass it along. The part number if you are interested is 2Z830, ( No I didn't pay that crazy price Icon_rolleyes ) You might be able to find something that is similiar. It is tedious and took over an hour of back and forth to get it wound. I used 40 ga which seemed to work fine.

Good Luck.

Glenn

Happily back in Illinois..not.
#7

I just sent a field coil to be rewound to these people:

http://alabamahistoricalradiosociety.org/index.html
#8

What did they charge you and whom exactly there did you contact?
#9

ciscod@bellsouth.net

I only used them once before and the "coil form had to be rebuilt" so it was $70 plus shipping (I sent the whole speaker.). It was a valuable console, so I didn't care about the cost. This time I just sent them the field coil and he hasn't told me the price yet.
#10

OK thanks, I will try to contact them and ask for the price.
#11

This fellow here has a series about restoring the shadow meter in a Philco 16B, parts 7 through 15 cover everything he had to do:

http://www.youtube.com/watch?v=sZe3QMgoyps

Regards
Arran
#12

Great set of videos! Certainly enough to assure me it's not something I can do. I would need better eyes and steadier hands, not to mention a lot of patience. Icon_sad

Jerry

A friend in need is a pest!  Bill Slee ca 1970.
#13

Yes I saw those - I watched them a week ago when I was trying to find out what folks do for this kind of coils.

I think though he made a mistake when he decided to use more turns to meet the resistance. I think the number of turns is more important. And it seems like he eventually had to go down in turns. Magnetizing is more important.
#14

DKinYorkPa

I think I will send those Alabama guys the whole meter - they said they could do it. They did not quote the price but the hint was at $55. Plus they offered to do the whole thing, the winding and the assembly which is good - soldering thin wires and then sealing the coil....not my fort eexactly.
#15

Morzh, I think you have made the right decision. I have always wondered if one of the wifes many sewing machines that will wind bobbins would work for something like this. Of course there is no counter for windings but it would be interesting to try. Sure winds that thread fast and lays it down nicely. Doubt that would work well.
Jerry

A friend in need is a pest!  Bill Slee ca 1970.




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