Anyone contact the guy who claimed to make new flybacks?

I stumbled across a thread a couple weeks back after he was apparently censored for posting an advertisement for his services inappropriately on this forum. I'm not talking about guy who made the ugly flyback that was on eBay a couple months ago (I've heard his products didn't work out).

I'm not opening a debate on whether or not he should have been kicked out, I'm just curious to know if anyone has or is willing to try out his services and/or knows his contact information. It is a shame it worked out the way it did since being able to wind replacement flybacks is a service many of us could use. Perhaps there's a place we could set up for such advertisements?

Be that as it may, I am curious to know more about what he could do and if his services are for real.



Thanks,
Joe

[David Roper]

I'm not talking about guy who made the ugly flyback that was on eBay a couple months ago

Or are you? From what transpired in the deleted thread it seems they are one and the same.

[bgadow]

That was my take on it, too. Odd that there would be TWO guys out there trying it.

[jroberts500]

I have thought about trying to rewind an old flyback. I imagined it would be hard to find specifications. I sincerely hope I never get that desperate. I'm beginning my search for an old color set and I imagine it likely needing the fly and a crt, so, I have also wondered if I could create a shop to rebuild crt's. Somebody needs to do it!

[John Folsom]

There are not two guys, they are one in the same. I evaluated the original ebay "prototype" flyback, and it was unworkable for several reasons. The builder has promised to make another attempt, and I will be bita-site testing it. I hope it works out, and I remain hopeful, and a little skeptical. Winding a flyback in a non-trivial exercise. But if he is successful, the collecting community will beat a path to his door!

[Chad Hauris]

Is there a proven industrial winder of transfomers that might be able to take this job on...like Peter Dahl co. can rewind HV transformers and chokes for radio transmitters (of course the flybacks would be a lot finer wire).

[old_tv_nut]

I looked at the Peter Dahl site - they seem to specializw in large iron core transformers. What is needed is someone who at least knows about ferrite core transformers for switched-mode power supplies.

ther is some tutorial material at

http://repairfaq.ece.drexel.edu/sam/flytest.htm

that explains that a fflyback uses a controlled air gap so that energy is stored in the inductance, whereas a typical non-flyback transformer is transfering energy continuously and not trying to store it.

[old_tv_nut]

After reading more of the repairfaq site, I really have my fingers crossed that John Folsom's contact can do something. The chances seem to be slim, though. The site points out that the windings are extremely fine (often #40 or so, very delicate) and need to be wound in many layers. (I think it mentioned mylar tape, but to meet UL, the tape has to be fire retardant, like Nomex.) It also says that people who worked at a TV manufacturer reproted they had one guy who did the design. I want to verify that from my experiences at Motorola and Zenith. AND, the guy who did the design was not the same guy who wound the transformers, which took a very meticulous coil expert in itself. An additional problem with flybacks is that the secondary is self-resonant due to the distributed capacitance, and this must be correct - this means that the flyback design cannot be tested until the whole thing is potted in the intended manner. Trying to figure out what this resonance wsa supposed to be from a burned out example seems difficult too.

The best practice was to run the prototype through the production potting line so the prtotype potting is made to the same composition and thickness as will be used in production. The designer measures the result, and orders a new prototype with adjusted winding parameters (number of layers and turns per layer, wire size, etc.), and they try it over again until they get it right. I manged to apprentice to the point of designing the flyback for a small black and white set by starting from a known design and modifying it a bit at a time. Starting from complete scratch would require making a series of test windings to calibrate your process.

One of the innovations that saved a temendous amount of time was concocting a mixture of different grades of silicone liquid that would mimic the final solid silicone potting. The the flyback prototype could just be wound and tested while resting in a bath of fluid, so the turnaround time was reduced. A final test of a properly potted one was still needed to verify the design.

Another aspect of design is that the potting compound must contain fire retardant for a product to meet UL. However, the fire retardant degrades the dielectric characteristics of the potting compound, so it is necessary to carefully adjust the formulation - too much fire retardant will actually cause overheating.

So, John, good luck! My opinion: it just may be possible to tackle this, but it's not simple, and the time will have to be donated or you couldn't afford it.

[blue_lateral]

On Pete Dexnis' site, there is a page on the info exchange by a ct100 owner in the UK named Mike. He said in part:

--snip--

Incidently, I know of a very good transformer re-winder here in the UK that can tackle most flybacks and field transformers at reasonable cost if its of any interest to you. I've often seen US collectors say that a dead flyback can't be re-wound -- not true. I'm almost certain that a 45 year old flyback operating at 20 kV would have a very short life expectancy!

--snip--

This could be worth looking into...

linky

John

Having not seen the original thread (most of which appeared to be deleted by the time I stumbled onto it), I didn't realize that poster was the same guy who claimed to wind the ugly CTC-4 flyback.

Funny how the reference is made to a guy who can wind flybacks, yet the actual contact info on that site wasn't posted. It seems there's always some mythical source of rewound flybacks, but it's like finding the Lach Ness Monster or Bigfoot.



Joe

[Jonathan]

Power transformers and flybacks are one of the main things other that the CRT that can make or break a TV, and they usually are the hardest to find/aquire/repair/rewind/rebuild. I think all of us who restore and collect TVs want them to operate forever without anything break or fail. But what I'm curious about is if the main reason for failure of flybacks is bad resistors or capacitors. With modern components with almost indefinate lifespans at normal conditions, or atleast conditions seen in a TV, shouldn't a flyback run almost forever? I know heat and age of materials used in flyback construction are factors that can shorten the timespan to failure, but with modern components and normal conditions seen in a TV with adequate protection against line surges and spikes, will a flyback in a properly restored set operate almost indefinately?

Jonathan

[frenchy]

I doubt it's indefinite, the insulation of the fine wire inside eventually degrades, they usually short internally, not to the cage. But there are certain concrete things that can cause flybacks to be destroyed, not to just wear out.
- Tubes in the HV section shorting the filament to other parts in the tube... resistors going bad in the HV regulation circuit and letting the HV go out of control till that 40K volts finds a way to get out (like thru the flyback insulation!).
- Black dust accumulating in the cage can increase the likelyhood of corona and HV leakage, should be cleaned up.
- Shore up any missing insulation/wax on the flyback correctly.
- I think some of the 'GT' variants of some tubes may be sturdier and less likely to short, like 1b3GT and 3a3c. Just replacing the rectifier tubes in the HV section with new ones that are more up-to-date GT or A types etc. is a good idea.
Then there are always peculiarities to certain chassis's. For example on my CTC-16 I asked around and there are a few weak spots that need to be addressed, namely a couple of chroma board solder pads that should be shunted with a separate wire. Back then, the joints used to come loose from board heat warpage and this sent the HV sky high. I was also given some tips on getting the current in the flyback as low as possible (for reduced heat) by using some tricks with extra caps in the circuit. That's another biggie with flybacks, dialing in the horiz. efficiency adjustment coil, width adjustment, experimenting with different H.O. tubes etc. to get your current there as low as possible and still perform correctly picture-wise.
Adding some ventilation holes to HV cage lid can help too if it doesn't have any, but you have to make sure you don't leave new sharp points in the metal in the process which could induce corona (HV leakage).
I would suggest posting here and in the antique radio/phono newsgroup with your chassis number, lots of old tv repair guys there who remember what the weak spots were on what sets.....Frenchy

[Jonathan]

frenchy,

Ahh, that pretty much answers my question. Since it's high voltage, failure is more common than at B+ or lower voltages. It's definately good to treat the HV section of any TV with great care, not only for safety, but long and reliable operation.

joe_tbird,

I see you are the owner of that nicely restored CTC4 on ebay. Hope you enjoy it.

Jonathan

[andy]

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[frenchy]

Let's see I've had 7 old tvs (all made from 1949 to 1966) and they all had great pic tubes and good flybacks. One or two had a remanufactured pic tube, others seem to be all original. Even one flyback that looked terrible (Zenith porthole, black wax stuff all melted off in chunks) still worked fine, I recoated it with silicone. Course you never know if one of these is on it's 5th flyback or not...Frenchy