Another local Hoffman! COLOR!

[Yamamaya42]

Originally Posted by dieseljeep

When the high voltage rectifier winding arced through, I used to cut out the wire and used an EDI solid-tube which was a solid-state replacement for a 3A3/3DB3 or a 3AT2, depending on the set. It was especially important on a Zenith that used resistance wire for the winding.
RCA's seldom needed it because the flyback was replaced before.

thought about that, but when I tried the Philips ECG ECG508 / R-3A3 45KV Silicon Rectifier in my CTC-16XL, it self destructed in 90 seconds for some reason.

bit worried about trying one again.

[old_coot88]

Originally Posted by Yamamaya42

...I tried the Philips ECG ECG508 / R-3A3 45KV Silicon Rectifier in my CTC-16XL, it self destructed in 90 seconds for some reason.

Are those actually silicon? I always suspected they were a selenium stack, and never trusted them.

[Yamamaya42]

Originally Posted by old_coot88

Are those actually silicon? I always suspected they were a selenium stack, and never trusted them.

shango066 also tried one in a roindie, and it fried in 20 min.

so I tend not to trust them.

if anything SS, perhaps this or something like it.
http://hvstuff.com/40kv-1a-high-volt...fier-tesla-ham

[dieseljeep]

Originally Posted by old_coot88

Are those actually silicon? I always suspected they were a selenium stack, and never trusted them.

I never had one fail, so I don't know if they had a string of silicons or selenium stack. If I knew they were selenium, I never would have used them, knowing that the focus rectifiers were.
I used the EDI brand, not the ECG.

[Yamamaya42]

Originally Posted by dieseljeep

I never had one fail, so I don't know if they had a string of silicons or selenium stack. If I knew they were selenium, I never would have used them, knowing that the focus rectifiers were.
I used the EDI brand, not the ECG.

i did a quick look, but sadly any compatible EDI brands are quite unobtainium.

So the choices fixing it to the original spec, which I will try first, then go with that huge 1A 40kv SS diode later if all else fails.

[Yamamaya42]

Turns out that site with the 40kv ss diode is fake, the entire site is nothing but a rip-off.
However, I did find a EDI Solid-Tube R-3DS3 7541 on eBay, a 3DS3 is not compatible, but as a last resort, the SS R-3DS3 can be made to work, as it's well within spec.

[dtvmcdonald]

Originally Posted by old_tv_nut

Or as an old Zenith engineer once said when shown the first RCA experimental color TVs, "27 controls, each one making it worse!"

There are 82 adjustments on a CT-100. This includes only one channel strip. It includes the six position and tilt adjustments of the yoke, which are
all very criticasl for perfect convergence.

I adjusted every one on my TV, and they all DID make it better! (except the RF on the strips, which were OK.).

In fact I added an 83rd one, one additional adjustment in the color matrix ..
and that really did get it better, even after changing all the fixed resistors to 1% ones.

[Yamamaya42]

EDI Solid-Tube R-3DS3 7541 ordered

HV wire will be here tomorrow, FBT coated VERY well with dope and cured, and ready for new wire, I doubt it can arc any more.

one way or another it WILL work.

[John Adams]

Originally Posted by Yamamaya42

Turns out that site with the 40kv ss diode is fake, the entire site is nothing but a rip-off.
However, I did find a EDI Solid-Tube R-3DS3 7541 on eBay, a 3DS3 is not compatible, but as a last resort, the SS R-3DS3 can be made to work, as it's well within spec.

Here is the link to what could be a useful site to check out a website.
My search was for kalesafe.com and you can see the results. There is a search feature at the top. https://www.scam-detector.com/valida...fe-com-review/

[Yamamaya42]

As Tom Petty once said, “the waiting is the hardest part”

Amazon SHOULD bring the new HV wire today, with which I hope to re-wind the newly doped FBT and try again with the 3A3C.

Did a resistance check on it.
http://suzaku.live-evil.org/fbt112.jpg
It all mostly agreed with what SAMS says except fot the one 4.7 ohm reading which was about 10, but I have seen this before, where what they had listed did not match real time with what was in the sets and there was nothing wrong.
Especially when there are 2 different FBTs listed in the SAMS, Hoffman # 033-013000 & 033-012700
both replaced by merit hvo-234c / stancor ho-601c / triad d-304.

And if worst comes to worst and this CRT is no good, ETF does have at least 1 or more that will fit in this thing, :O

[dieseljeep]

Originally Posted by Yamamaya42

As Tom Petty once said, “the waiting is the hardest part”

Amazon SHOULD bring the new HV wire today, with which I hope to re-wind the newly doped FBT and try again with the 3A3C.

Did a resistance check on it.
http://suzaku.live-evil.org/fbt112.jpg
It all mostly agreed with what SAMS says except fot the one 4.7 ohm reading which was about 10, but I have seen this before, where what they had listed did not match real time with what was in the sets and there was nothing wrong.
Especially when there are 2 different FBTs listed in the SAMS, Hoffman # 033-013000 & 033-012700
both replaced by merit hvo-234c / stancor ho-601c / triad d-304.

And if worst comes to worst and this CRT is no good, ETF does have at least 1 or more that will fit in this thing, :O

The only Hoffman set I worked on, a 23" CTC15 clone. The flyback Sams specified was the wrong one. It was for a 70deg round tube set. It didn't work properly!
A friend worked for a Muntz dealer, so I ordered a flyback from him. Worked great and it was a lot cheaper!
That was about 50 years ago.

[Yamamaya42]

Originally Posted by dieseljeep

The only Hoffman set I worked on, a 23" CTC15 clone. The flyback Sams specified was the wrong one. It was for a 70deg round tube set. It didn't work properly!
A friend worked for a Muntz dealer, so I ordered a flyback from him. Worked great and it was a lot cheaper!
That was about 50 years ago.

OK...
this just got a bit stranger.
the replacement FBTs listed in SAMS are FOR the RCA CTC-15 .
was the same one used in the 17?
this is odd
its not SAMS that makes the subs, but merit/stancor/triad right?

[Electronic M]

The CTC-15 was a roundy the CTC-17 was a rectangular...The deflection angles are different between the two so RCA definitely used different flybacks in the 2 chassis, and I have a hard time buying that Hoffman could have made a roundy fly work in a rectangular set.

[Yamamaya42]

Originally Posted by Electronic M

The CTC-15 was a roundy the CTC-17 was a rectangular...The deflection angles are different between the two so RCA definitely used different flybacks in the 2 chassis, and I have a hard time buying that Hoffman could have made a roundy fly work in a rectangular set.

Then the list in SAMS must be wrong, just as DJ ran into 50 years ago!

[dieseljeep]

Originally Posted by Yamamaya42

Then the list in SAMS must be wrong, just as DJ ran into 50 years ago!

The Sams was wrong!