Anyone repaired Accutron Coils...?

[HCII Accutron 2182D]

Well--the coils I worked on have now been good and in intermittent operation now for about 6-7 years.
--That was when I first got interested in this amazing design of watch. I had always been interested in watches/repairing etc--even when I was in school....

So--back 7 years ago, I bought around 5 of 218, two 219 and two 214, over the space of a year or so.

A few of the 218 had O/C Coils, --water damage I suspect--the electronics were good.

The 219's had good coils, but the electronics were duff....Weird as one had never been worn, still had the tag on the back...

Amazingly, the 214's had good coils...

So drawing on my knowledge as an electronics engineer, I set about trying to renovate what I had, seeing that I dont have the spare cash to --as my partner would say--Waste!

The 219 watches first-

One of these were in great physical shape Inside, although the GF case is pretty badly damaged on one lug--Both of my 219 are 'signatured' presentation watches with GF cases,--so nothing 'special' (Cant do 'special'--Too expensive!)

As I said, the coil itself had continuity and approx the expected DC Resistances.--But absolutely refused to Hum or run in any way.
--I first suspected the Transistor, but a quick check indicated the transistor was just fine.--That left two other components or a break in the connections somewhere...
I checked the Resistor, a 2.2meg carbon-compo 0.125W part and that read within tolerance.
The capacitor did not have any electrical leakage and did not appear open-circuit either....

No breaks in connections or wiring could be found anywhere.

I decided to replace the cap anyway, with a modern 'Surface-Mount' 0208 size, 0.22uF 30V part
--The original is a 0.2uF of unspecified voltage rating, a tiny steel cylindrical thing.

Bingo--Up it came and has run since....

I checked the original cap, and for some unknown reason its value had increased from 0.2uF to well over 1.0uF....Guess this must have damped out the feedback signal to the transistor sufficiently to kill oscillation, and prevent hum...

The other 219 responded in exactly the same way--New cap and away to go.... Bad batch of caps maybe!

Now the 214's...

They both initially worked. although both in very poor condition case-wise, the Spaceview had a missing crystal and most of the time-changing parts, even the fork shock bridge was missing. The movement however does run.

The other, a rather plain and neglected watch had a case of dial-pox and looked hideous, but again did actually run initially.
During cleaning/messing round, somehow I killed the transistor in the coil-pack.--Coil windings just fine
--Only thing for it then--as I wasnt going to rip apart the incomplete possibly original Spaceview, was to rebuild the electronics.

I selected a PNP Silicon Transistor, 20V rated and as I recall 100mA, 200mW part-The original was a Germainium PNP transistor as this is a 'three-wire' 1963 watch and the original transistor is unobtainium, So I got the smallest PNP silicon that I could get locally--Even then, I had to carefully file the top to make it just a little shorter to fit in the space of the coil-frame. I didnt have access to any SM transistors at the time
I removed all the original gubbins and built up a a chain of resistors, 2 of 1meg and 1 of 6.8K, all from surface-mount 0208 parts and also the capacitor of 0.22uF just like I used in the 219's

This was fitted, and again success--we had a hummer!--BUT It Looks Hideous--In comparison to a Proper set-up--Surface-mount components are NOT colourful, just little oblong bricks of black and brown...

I had read somewhere on the web of a guy who had done much research into just the mode of failure of an Accutron Coil. It was apparently discovered under electron-microscope that the varnish/epoxy coating had developed minute cracks and had allowed moisture in that eventually rotted out the copper of the windings....
--So I cleaned the coils with tricholoroethane and coated them carefully with a product called, 'Ultimeg' which is a reddish brown paint, exactly like a gloss 'red-lead' and intended for insulation/antitracking for industrial motors and other wound components... I applied a light even coating and also extended along the connecting wires from the coils to the points where they join the rest of the electrics.

Due to the dial of this watch being in such poor condition--You can guess what I did!

So--Now I have probably the worlds Ugliest Spaceview, which as served me well for a number of years.

--Anyone else replaced components in their coil assays...?

My next project--IF I can get the wire--will be to attempt a Coil Re-wind....
--cell-coil of a 218 shouldnt be too hard, but those of a 214 are gonna be a real problem!

[skypilot]

I must admit that I didn't understand all of that but I can sure see where it could be a benefit to have an electrical engineer here.
I have heard of people trying to rewind Accutron coils but can hardly imagine what a tedious job it would be.

[HCII Accutron 2182D]

My thoughts on it are--IF someone Made it initially, Why cant I--with some research, care and attention, re-build it....

--Its only a coil after all........And, there's a finite number in the world, which gets less every week, as no-one is making new ones that I am aware of. (Exception would be for the 50 year anniversary 214 that Citizen re-issued,--but IS this a direct swap for an old 214,--who knows...)

Ive made many transformers over the years, some with many thousands of turns, carrying very high voltages--But the issue here is the scale and size.

I have a small hand operated bench transformer winding machine with turns counter etc, so I'm sure this could be used.

I did see somewhere, that the wire gauge is 0.015mm and approx 8000 turns are in the 'average' coil, depending on calibre and which coil it is....

More research and a dismantling of a dead coil needed yet....
--I think its worth a go anyway....

[akkatron]

I want to do work on coils as well. Keep an update on any work as I'm very interested. All we need now is a way to remake index wheels.