Found a Hoffman colorcaster television local.

don't have it yet

http://suzaku.live-evil.org/hoff112.jpg
1967 w a 23EGP22 CRT
:D

looks at the SAMS folder...

This thing is an RCA clone! :scratch2:

...with a Zenith picture tube!

...with a Zenith picture tube!


Yes, it does look like a Zenith type cataract, but the sticker on the back says sylvania, did they use the Zenith method?

http://suzaku.live-evil.org/zenuth.jpg

Zenith didn't make a 23EGP.

BTW, what's the "Zenith method"?

Sylvania CRTs do get Zenith style cataracts, and supposedly respond to the same removal methods. The only Sylvania color CRT I've had was a post safety glass tension banded tube so I've never verified what I have read that they respond the same.

Zenith didn't make a 23EGP.

BTW, what's the "Zenith method"?

From what I have seen here and there, there are only 2 major types of methods (styles) of bonded safety glass used in these things, RCA, which turns white & cloudy (moldy) looking, best removed with heat, and the Zenith type of bond, which turns green and gummy, best removed with thin wire, and a lot of patience and strong hands! :)

As E.M. Has confirmed, this tube does indeed have the Zenith type of bonding used for the safety glass, meaning it will be much harder, and not to mention hazardous than the RCA 21FJP22 ones I have done before.
As I have heard that these tend to be more unstable in the process than the roundies, :(

From what I have seen here and there, there are only 2 major types of methods (styles) of bonded safety glass used in these things, RCA, which turns white & cloudy (moldy) looking, best removed with heat, and the Zenith type of bond, which turns green and gummy, best removed with thin wire, and a lot of patience and strong hands! :)

As E.M. Has confirmed, this tube does indeed have the Zenith type of bonding used for the safety glass, meaning it will be much harder, and not to mention hazardous than the RCA 21FJP22 ones I have done before.
As I have heard that these tend to be more unstable in the process than the roundies, :(

I'd call it mid-level danger. The 23EGPs with RCA style cataracts tend to implode when heated worse than round or later rectangular tubes. The Zenith guitar string method has has a 100% success rate for me on the yellow/green cataracts, and doesn't use heat.

If you remove the cataract with heat it'll probably implode. If you remove it with just guitar string it'll probably be fine, but a raw 23EGP has a slightly higher implosion risk just sitting there than other color tubes.

I have an RCA-style (moldy white crap) cataract on a 23EGP22 in an Admiral combo.

Tom: it sounds like no heat is safest, maybe even baking it in sunlight is a risk. The guitar string may need to be heated ala current source?

I have been looking at the SAMS for a while now, and just LOLing! :)
It's obviously an RCA CTC-17 -ish type clone, with mods, but what got me was the totally pointless mod of what is called the “color caster” color indicator circuit, which is 2 NPN transistors hooked to the color bandpass, which turns on 3 lights when color is present.... WHY BOTHER? :O


HEY, WE HAVE COLOR! let's light up the color, and tint controls! :D

I have been looking at the SAMS for a while now, and just LOLing! :)
It's obviously an RCA CTC-17 -ish type clone, with mods, but what got me was the totally pointless mod of what is called the “color caster” color indicator circuit, which is 2 NPN transistors hooked to the color bandpass, which turns on 3 lights when color is present.... WHY BOTHER? :O


HEY, WE HAVE COLOR! let's light up the color, and tint controls! :D

Well, hypothetically, the color could be turned all the way down accidentally by kids or even the supposedly intelligent owner.

Of course, in later years we had cable systems that never turned the color burst off on anything including black and white movies, producing crosscolor when it should have been killed. By then no sets had a color indicator, but it would have been useful to me after I turned the color down deliberately on black and white movies.

Edit: well, not really useful, as it would always indicate color, but it might remind me to turn the color up again.

1 is good, 2 is a charm, 3 is nuts! :P

http://suzaku.live-evil.org/crazy-color.jpg

Wow - they even had a color defeat switch. This would make the indicators useful as the user might have turned the color off with the defeat switch.

The reason for a color defeat switch was for cases where a set was used in a fringe area and the noise might have made the color killer unreliable. The color killer control could be set to make sure color programs got through, but the switch could be used to eliminate color snow on black and white programs without disturbing the color control setting. Obviously the color killer and color indicator could have different thresholds. I wonder if the color indicator tended towards false positives or false negatives under noisy conditions.

I always thought the color defeat switches on the various brands were to eliminate color on fringe color programs where the picture looked worse in color with snow than without color.

What gets me is the 3 parallel lights, " Easy vision cinema " Say what? :scratch2::D

Well, that seems to be a pointless gimmick! :D
http://suzaku.live-evil.org/pointless.jpg
a 2nd CRT bias? and up front where the user can set it? :O
wow...

Mind boggled...
To me it seems that adding that gimmick just gives a faster way to wear out the green/blue guns, having a master CRT bias pot on the back tied to the cathodes of the Y-AMPS, and another on the front, on the CRT green/blue G1 that the user can set?

This is prob why it was replaced with a new one in 1973.
No telling what condition it's in now, won't know till I pick it up on Saturday. :o

I always thought the color defeat switches on the various brands were to eliminate color on fringe color programs where the picture looked worse in color with snow than without color.

This philosophy might be followed by an engineer, but you can bet that the average owner would want that expensive color set to show even noisy color if it was available.

Mind boggled...
To me it seems that adding that gimmick just gives a faster way to wear out the green/blue guns, having a master CRT bias pot on the back tied to the cathodes of the Y-AMPS, and another on the front, on the CRT green/blue G1 that the user can set?

This is prob why it was replaced with a new one in 1973.
No telling what condition it's in now, won't know till I pick it up on Saturday. :o

It may have been the pot equivalent of the sepia switch om my old airline console. The idea was that on B&W films and TV shows older viewers that watched film before TV existed may prefer the look of sepia monochrome film stock and wish for a way that their TV could duplicate it...It looks stupid on color shows but I can see why some people might like it on monochrome shows.

Mind boggled...
To me it seems that adding that gimmick just gives a faster way to wear out the green/blue guns, having a master CRT bias pot on the back tied to the cathodes of the Y-AMPS, and another on the front, on the CRT green/blue G1 that the user can set?

This is prob why it was replaced with a new one in 1973.
No telling what condition it's in now, won't know till I pick it up on Saturday. :o

The Easy Vision Cinema doesn't affect drive levels, only tracking. Not sure of the visual effect with this hookup, but probably a variation between sepia, neutral and bluish shadows.

Some Motorola sets had this third color control (they called it Tint, and called the phase control Hue, rather than Tint, as RCA and everyone else did). In the Motorolas, it was actually useful if the viewer knew how to use it (which nobody did), because the DC coupled Motorola single tube demods tracking would change depending on the mismatching of the tube sections. In the cheaper models, the control was replaced with fixed resistors, and if you replaced the demod tube, you may have needed to adjust G2s to get neutral tracking again. The early rectangular high end Magnavoxes had an automatic color switch (with a fancier name I can't recall) that reduced green-purple color saturation and set the tracking to sepia. It reduced the variation on skin tones, but gave the "tan cowboy on a brown horse riding into an orange sunset" kind of picture.

This philosophy might be followed by an engineer, but you can bet that the average owner would want that expensive color set to show even noisy color if it was available.

Of course, if the color AFC section was crappy and couldn't maintain lock under noisy conditions, that would certainly make you want to turn it off.

I had never seen an adjustment like that before in a vintage TV, they must be rare, I have seen things like “color temperature settings” in LCD types, but in all the years since HS till now, this is the first time I have seen one in a tube type tv. :O

I had never seen an adjustment like that before in a vintage TV, they must be rare, I have seen things like “color temperature settings” in LCD types, but in all the years since HS till now, this is the first time I have seen one in a tube type tv. :O

The color temp setting in an LCD should not affect the tracking (that is, making shadow color different from highlight color) - it shouild be more like the drive settings in a CRT.

Note that with the excellent tracking stability of modern digital video hardware, deliberate separately controlled mistracking of highlights, midtones, and shadows is used in cinema and now even in Photoshop still image processing, where it is termed "color grading." It can be effective for setting a visual mood, but can also lead to fads like the strong orange-cyan look of some movies.

The color temp setting in an LCD should not affect the tracking (that is, making shadow color different from highlight color) - it shouild be more like the drive settings in a CRT.

Note that with the excellent tracking stability of modern digital video hardware, deliberate separately controlled mistracking of highlights, midtones, and shadows is used in cinema and now even in Photoshop still image processing, where it is termed "color grading." It can be effective for setting a visual mood, but can also lead to fads like the strong orange-cyan look of some movies.

So this basically allows the watcher to alter the balance points of the color demodulation G/B on the fly to adjust to the viewer's tastes? Fancy!

So this basically allows the watcher to alter the balance points of the color demodulation G/B on the fly to adjust to the viewer's tastes? Fancy!

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

And yet, with all the “perfection” of ATSC,etc, it seems that the color still isn't always consistent. Go figure.

Almost The Same Color?

And yet, with all the “perfection” of ATSC,etc, it seems that the color still isn't always consistent. Go figure.

Almost The Same Color?

Not the fault of the ATSC system, which does not deal with color except to transmit the bits.

And yet, with all the “perfection” of ATSC,etc, it seems that the color still isn't always consistent. Go figure.

Almost The Same Color?

If this were Reddit we'd have 100 Europeans piling in right now to insist that PAL is vastly better at color, and that NO their TVs most certainly do not flicker!

UPDATE!

I got it!!

VERY bad news , CRT is damaged!
pin 12 has been broken off of the base, this is prob why they dumped the set.

http://suzaku.live-evil.org/0716221359a.jpg
http://suzaku.live-evil.org/0716221403.jpg

good news is, I may have been able to fix it by tacking a wire to it.
http://suzaku.live-evil.org/0716221404.jpg

flyback looks OK

now I gotta start bringing back to life

one very dirty looking RCA type looking chassis.

http://suzaku.live-evil.org/0716221748.jpg
http://suzaku.live-evil.org/0716221746a.jpg

Progress, and step back, sort of? :O

After seeing the broken pin on the 25AP22A ( or so the sticker on it says ) , and not knowing if my fix attempt will work or not. I tried to bring the set slow up on Variac, this fond that C3 was REALLY bad, as it got hot VERY fast.

So I replaced all the sections of it, and tried again, THIS time power came up, I got hiss in the speaker, I heard vert start, but NO HV....

looked inside the HV cage, the HV rect was lit, and very hot. Pulled the cap off and got a good strong AC arc all over the place, removed the HV shunt, no change,,, BAD 3A3A, of which I have no spares.

so now, before I can make sure the CRT is any good, I must wait for the new 3A3C to get here so I can get HV up. :(

OK...
It was NOT a bad 3A3A :O

http://suzaku.live-evil.org/0717221006a.jpg

had a burn out in the heater wire FOR it,,,,

crispy carbon!

http://suzaku.live-evil.org/0717221025.jpg

after the repair

Yikes. Hopefully that arcing and high current didn't hurt the rect of worse the fly.

Yikes. Hopefully that arcing and high current didn't hurt the rect of worse the fly.

The Fly is OK, the way i found it was, I used a handful of 20KV 5mA HV High Voltage Rectifiers i had, doubled up on them so they would not fry.
but quickly found that when NOT hooked in circuit i had 25k HV, but they would burn up as soon as I tried to wire them into the normal way.

that is how i found 1he 5m to ground short on the heater winding for the rect tube and went to look for the problem.

When I looked at the two pictures of the chassis out of the cabinet, I noticed that there were two transformer cans with a piece of black tape over the top adjustment hole. Any idea why they were covered? Was it a way of the manufacturer to discourage "diddlers" from adjusting these cores?

When I looked at the two pictures of the chassis out of the cabinet, I noticed that there were two transformer cans with a piece of black tape over the top adjustment hole. Any idea why they were covered? Was it a way of the manufacturer to discourage "diddlers" from adjusting these cores?

Curious. Can't think of a reason offhand. Possible that someone who worked on it did that?

What circuit are the taped cans in?

For relatively low frequency circuits where the stray capacitance is not significant, it would be possible to include a capacitor inside the coil assembly and automatically pre-tune it during the assembly manufacture, before installing on the printed circuit.

Motorola's coil plant made some pre-tuned assemblies, but I always thought they still had to be adjusted after installation in the chassis. I used eight pretuned coils (IIRC) in our redesign of the CBS video film player (EVR), at frequencies around 900 KHz and 1.8 MHz, [linear-phase chroma pilot and chroma subcarrier filters] but they definitely had to be touched up in the final product. This was due to the differences in strays between the winding machine and the final product. It would have been possible to tune samples in the final product and then have the winding machine duplicate the tuning, but it was not worth it because the printed circuit might be changed at some time (material or layout) and change the strays.

When I looked at the two pictures of the chassis out of the cabinet, I noticed that there were two transformer cans with a piece of black tape over the top adjustment hole. Any idea why they were covered? Was it a way of the manufacturer to discourage "diddlers" from adjusting these cores?

no idea why it's like that :o

Good news is, the HV rect is OK!
bad news is, my patchwork did not hold.
the HV blasted through / around the heat shrink tubing and found a path to grd and arced again, I guess i should not have clipped it down

now time for more drastic measures.

http://suzaku.live-evil.org/0717221306.jpg

huge piece of tubing filled with silicone
this will take many hours to cure
and If it's dry enough to put pack together late tonight, I will slop more on it.

hope to be ready to power it again mon night.

using this stuff
https://webaps.ellsworth.com/edl/Actions/GetLibraryFile.aspx?document=23605&language=en

I am really hoping this CRT is going to work, otherwise things will really suck pretty fast T_T

Once you have a good CRT change the bad HV wire properly. When that insulation kludge fails on you again a few weeks or months down the road you'll wish you had replaced the wire.

a very dopey looking FBT

http://suzaku.live-evil.org/0717222342.jpg

there were some cracks in the outer " doughnut " that was allowing arcing.
but unlike the ones in the roundies, this one seemed ti be made of tar or something and not rubber.

there was no carbon tracks that I saw, just cracks and so on.

as far as replacing the heater winding, i really don't have the type of wire to do it right now, or really know what to even get to use.

Thinking conservatively, it would be rather foolhardy now NOT TO replace the burned wire now while I have the FBT out of the chassis with it easy to get access to.
Not really knowing what type of wire to get, I made an educated guess.
Copper Core Flexible Silicone Wire Cable Red 10M 32.8Ft (22AWG 40KV)

40KV, well above what this set should generate, 22AWG, should be thin enough for the clearly 2 turns that I see around the core of the FBT, and hearty enough to power the 3A3A/C

Re-post of original FBT photo.

http://suzaku.live-evil.org/0716221404.jpg

You can clearly see 2 turns on the heater winding on the core, should not be too hard to replace with the new wire ordered.


You can also see the crack (cracks) in the FBT outer layer which looks to be made out of some kind of hi temp tar, which was easy to melt with an soldering iron, there was a tendency for corona arcing from these cracks but saw no real carbon, and thought it very risky to try to remove it, so I covered it with several layers of dope.

Once you have a good CRT change the bad HV wire properly. When that insulation kludge fails on you again a few weeks or months down the road you'll wish you had replaced the wire.
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. :D

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. :D

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.

...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.

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-voltage-diode-hv-hf-rectifier-tesla-ham

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. :thmbsp:

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. :thmbsp:

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.

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.

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.

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.

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/validator/kalesafe-com-review/

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

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. :sigh:

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. :sigh:


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?

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.

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! :yes::D

Then the list in SAMS must be wrong, just as DJ ran into 50 years ago! :yes::D
The Sams was wrong!

Redone FBT ready to go back in!

http://suzaku.live-evil.org/0719221857.jpg

https://www.youtube.com/watch?v=xos2MnVxe-c
http://suzaku.live-evil.org/0719222043a.jpg

and there is color! dirty! o
http://suzaku.live-evil.org/0719222046.jpg

the repair to the broken pin DID work!

the video is sloppy, prob some weak tubes, many orig ones still in there, but now I know all I need to to move on to the restoration stage,

https://youtu.be/mCyPldcQ9as

first video

I have a question in regard to your Hoffman Colorcaster TV. I looked at the photo of the service adjustments for this set (of which there must have been twenty or more, as I would expect in a 1956 color TV) and saw, to my surprise, a brightness control. My question is this: Why would the brightness control be located on a control panel which has mostly service adjustments, which of course are not to be touched by anyone other than a qualified service technician? Or was there another brightness control wired in parallel with it, the second control being the user brightness adjustment?

In any case, I would think two brightness controls would be one too many for any TV, color or b&w. I could understand this if the second brightness control has a definite function, such as setting the maximum range of the user's control, but otherwise I am at a complete loss to explain this. Most later color sets (late 1960s on) had only one brightness control. Was there something about 1950s color televisions which actually required the sets to have two brightness controls, or was the second control used, as I said, to limit the range of the user's brightness control?

Thank you for any and all information on this, as this TV is the first one I have ever seen (I have never seen a Hoffman TV in person) with a brightness control on a panel normally reserved for service adjustments. I also saw a few other controls on this TV's service control panel which are ordinarily service adjustments only, again to be adjusted only by qualified service technicians. Were these controls wired in such a way as to limit the range of the existing controls? If so, as I said, this is overkill of the worst sort, as most later color sets only had one control for most service adjustments. These controls almost certainly would not be noticed (and should not have been) by the average color TV set owner, anyway, as many color TVs of the '50s and even into the early 1960s had a warning label pasted somewhere on the inside of the TV cabinet, to the effect that service adjustments, tubes and other parts of the set must not be touched except by a qualified TV service technician.

I have a question in regard to your Hoffman Colorcaster TV. I looked at the photo of the service adjustments for this set (of which there must have been twenty or more, as I would expect in a 1956 color TV) and saw, to my surprise, a brightness control. My question is this: Why would the brightness control be located on a control panel which has mostly service adjustments, which of course are not to be touched by anyone other than a qualified service technician? Or was there another brightness control wired in parallel with it, the second control being the user brightness adjustment?

In any case, I would think two brightness controls would be one too many for any TV, color or b&w. I could understand this if the second brightness control has a definite function, such as setting the maximum range of the user's control, but otherwise I am at a complete loss to explain this. Most later color sets (late 1960s on) had only one brightness control. Was there something about 1950s color televisions which actually required the sets to have two brightness controls, or was the second control used, as I said, to limit the range of the user's brightness control?

Thank you for any and all information on this, as this TV is the first one I have ever seen (I have never seen a Hoffman TV in person) with a brightness control on a panel normally reserved for service adjustments. I also saw a few other controls on this TV's service control panel which are ordinarily service adjustments only, again to be adjusted only by qualified service technicians. Were these controls wired in such a way as to limit the range of the existing controls? If so, as I said, this is overkill of the worst sort, as most later color sets only had one control for most service adjustments. These controls almost certainly would not be noticed (and should not have been) by the average color TV set owner, anyway, as many color TVs of the '50s and even into the early 1960s had a warning label pasted somewhere on the inside of the TV cabinet, to the effect that service adjustments, tubes and other parts of the set must not be touched except by a qualified TV service technician.


I'm not sure which docs you saw, but this set has only one true brightness control, however I have seen a “ sub- brightness” on some sets, perhaps that's what you saw?

SAMS does list a potentiometer on this to set kinescope bias, but this chassis has a switch for that.
This I can only attribute to the SAMS being for a Hoffman MO# MS-7322 and seems I have a MS-7322 (B), and this one SAMS is the only one there is, and it's close enough.

Sets with an "automatic" color switch of some kind would switch in a set of factory preset controls. Is that the case here?

Not sure, but this thing does seem to be a weirdly modded CTC-15 more than a 17, as I believe the 17 used a 1V2 or the like for focus, and this has SS like the CTC-15.

What ever it is, it does seem to be a Frankenstein creation! A little bit of this, a little bit of that, put into a pretty unique package!

AHHHH! That explains the odd behavior I saw last night!

Turns out that what is stamped out in the back of the chassis for the controls is NOT what they really are, they had stickers to show what they were, but they are long gone, what was marked as CRT bias was really VIDEO PEAKING, which was set in top most setting, and I sort of freaked when I changed it and lost picture and just got a blank raster.

Meaning there may be bad caps or more likely bad resistors, or the switch itself is dirty.

The REAL CRT bias adjustment is indeed a potentiometer, just as the SAMS says, but in a position stamped for something other than CRT bias, and when checked, much to my relief, it was turned 1/3 the way up when it made the video posted yesterday! :)

...
Turns out that what is stamped out in the back of the chassis for the controls is NOT what they really are...


Sheesh!
You are now officially a member of the guild of electronic archeologists!

Wow... I've been steered that wrong by Sam's before, but I don't think I've been lied to by chassis stampings... That's some 50s B horror movie level cheapness to fix stampings with stickers.

I did find ONE of the stickers that fell off, for top/bottom pincushion.
I did manage to clean up the convergence a bit, will make one more vid before I yank the chassis to haul upstairs to go over it with a fine tooth comb looking for out of spec parts.

It's looking rather well considering it's just been patched together and I did not put the blue lateral/purity assy back on yet.

The whole thing is just too big to bring upstairs, but at least they made it easy to unplug / reconnect the tuner / front controls, just 2 plugs & the IF.

https://www.youtube.com/watch?v=JOuNggMBsEE

2nd video

Looks a lot better!

So far, I have been over 1/3 of the color PCB and i have not found one out of tol resistor yet of the ones the I CAN test w/o removing them from circuit, starting to think that it's not worth checking them at this point any more :O

Recapping 1/2 done (electrolytic)

http://suzaku.live-evil.org/0724220102.jpg

Recapping 1/2 done (electrolytic)

http://suzaku.live-evil.org/0724220102.jpg

BTW you can embed that picture link so the forum displays it as a picture (the only reason I didn't is the resolution is so high it makes the text too small to read if zoomed out enough to see the whole pic....a lower resolution say 800x600 or 1080HD source image at the URL would fix that).

All you need to do is type this linkURL or in the "go advanced" reply page click the square that looks like it has mountains and a sun in it and it will automatically give you the [IMG] BB code.

I've been using Flickr and they give me an over complicated BB code to copy paste that I usually end up editing down so I can arrange my pictures in a neat grid.

1 is good, 2 is a charm, 3 is nuts! :P

http://suzaku.live-evil.org/crazy-color.jpg

Seems that all 3 of these gimmick lights are burned out. :O

Bad design.

NPN switch from the 6.3 fil power through a 1/2 wave rect, lighting up 3 2 volt bulbs through a 6.8 ohm resistor, as long as ALL 3 lamps are OK, all is fine, but if one burns out, then they ALL go because the voltage spikes.

they sell them in packs of 10, not gonna do it, I can get ultra bright yellow LEDs that run at 2-3 volts in packs of 20 cheaper.

Whenever I get a set that someone has converted to LED lamps I reflexively :puke: then switch it back to incandescent it's one of those things that gets under my skin about as bad as a set that someone painted some random ugly color.
I'm pretty well stocked with bulbs thanks to an estate sale of a mid-century EE who had 2 mason jars of spares, but when I use that up I plan to hit up rockauto...When I was doing my 6V 1947 Oldsmobile I had a look at every part they had and found a number of radio bulbs it used for the interior lights were DIRT cheap compared to mouser, and better than bob's capacitor who was my supplier before the estate sale. I think if I browse around 40s cars on rockauto enough I should find almost everything I typically need for consumer electronics.

I really don't mind using LEDs at all, they are cheaper than bulbs, and outlast them.

On second thought, since the source is 6.3v, and the drop across the transistor is pretty much nothing, w/o any bulbs, the switched on output should be about 6-7v so by adding a dropping resistor to ground, like 6-7 ohms should get me the 3.1v needed to use the ultra bright white LEDs, like I used in the GE TV.

Will just have to play till I find the right resistor value.

I really don't mind using LEDs at all, they are cheaper than bulbs, and outlast them.

On second thought, since the source is 6.3v, and the drop across the transistor is pretty much nothing, w/o any bulbs, the switched on output should be about 6-7v so by adding a dropping resistor to ground, like 6-7 ohms should get me the 3.1v needed to use the ultra bright white LEDs, like I used in the GE TV.

Will just have to play till I find the right resistor value.

Trying to picture this. Wouldn't a separate series resistor for each LED make more sense?

Trying to picture this. Wouldn't a separate series resistor for each LED make more sense?

The current draw of the old lamps was 3x .06a (180 ma total)
the draw of the 3 LEDS is 60 ma 3x20 ma.
The entire circuit in question is mounted on terminal strips behind where the bulbs go in.
I'm pretty sure all I need to to is add a resistor to gnd at the far side of r160, to keep the voltage about 3-4 volts, the LEDS are pretty forgiving about what you give them, and even if I damage a few while working out the correct value, I have 100 of them to experiment with, and they are small enough to solder into the shells of the old bulbs after the glass has been removed.

What has me scratching my head is 2.5v on the collectors of the NPNs, the source is 6.3v via a 1a SI rectifier, same type used for the main bias, which has a forward voltage drop of .6v, so is it really down to 2.5v from 6.3v via half wave?
Perhaps that there is no filter on the cathode of X11 that it's just being very inefficient?
Will have to look more closely at this.

1) It looks like the power is supplied as half-wave rectified AC through X11, so the DC reading doesn't tell the whole story.
2) The schematic doesn't give two sets of voltages, one with color present and one for black and white. Since the waveforms show color, I'd presume these are the voltages for the lights being on, but again it's not clear if the emitter of Q2 has plain DC or pulsating DC. 2 V DC is not going to be enough for the LEDs.
3) LEDs, like all diodes, have a sharp turn on, so trying to match the voltage is not good practice. Instead, you should look at the difference between [EDIT] the emitter of Q2 [END EDIT] and the diode drop and install a current limiting resistor in series with each LED.
4) In this circuit you are served a curve ball if all the voltages are pulsing half-wave rectified. Checking with a scope would be a good idea.

5) what you are hoping to find is that the peak of the pulsed DC on the emitter of Q2 is more than what's needed to make the LEDs conduct.

Well, what ever I end up doing will have to wait till i get the chassis back in and powered back up with the tuner in a position to play with it!

I just got finished with re-caping all the multi section capacitors, and some were REALLY tired, I'm surprised it worked as well as it did, for example some of the 80UF sections checked as low as around 32UF with horrid esr.

New ones all tacked under the chassis, and tacked with silicone, waiting for it to cure before i apply power to see if I messed anything up! :D

Then there is just 3 more topside.

https://www.youtube.com/watch?v=WmKhHiD1tUw

Recap complete and successful!

I may have to replace the Horz phase det.

as I said, I suspect that the phase detector is a bit weak, as I saw a little side to side jitters, and that there is many things to replace it with, I have one of these from work, https://www.st.com/resource/en/datasheet/stps41l60c.pdf

that should work fine from what I understand, Correct? :O

After searching and looking, I can really see no reason why this dual schottky diode (common cathode) I have should not work as a replacement for the old selenium horizontal phase detector, it even has almost the exact same footprint as the old part, so it should go in rather easily.
Will also replace the 2 390k resistors that bias it when I do it.

Will most likely do this at a future time when I adjust the HOT cathode current, if I ever figure out where the heck they hid the HV adjustment on this silly thing. :O

But for now, this weekend I'll be working on the LED replacements for the burned out bulbs.

After searching and looking, I can really see no reason why this dual schottky diode (common cathode) I have should not work as a replacement for the old selenium horizontal phase detector, it even has almost the exact same footprint as the old part, so it should go in rather easily...


I'd guess it's OK too, unless the reverse voltages in the circuit are higher than 60v.

It's just as I thought with this trio of lights behind the controls, w/o any bulbs, the voltage on the emitter was not @ 2v, but at 5.5 with no load. I even stuck in 1 6.3v lamp I had, and it lit that up to 1/2 brightness.

for the LEDs, i just have to find the right load balance to keep them happy.

I'd guess it's OK too, unless the reverse voltages in the circuit are higher than 60v.

http://suzaku.live-evil.org/phase.jpg

not close I don't think.
they are used in a 60v buck pws circuit, so I come across them all the time, and they looked perfect for the job, so I nabbed one from work with a unsuitable mounting hole, they were just gonna toss it! :O it works just fine!

https://www.youtube.com/watch?v=pHtgBbdJNqo

LED upgrade complete!

It's getting close to the point to where I'm gonna need to fix the cataract on the CRT.

There is pretty much little left to do on the chassis now. :O

The greyscale setup in the SAMS is a bit odd, of diff from what I have seen before, this may be cause it's a set with a POT for bias and not a switch.
but that last step of turning it up till it blooms, then backing off, seems a bit odd to me. :O


http://suzaku.live-evil.org/greyscale.jpg

Speaking of the cataract repair, since I have never done this type before, I was thinking of using,
Nichrome-28-Gauge-Resistance-Wire, and heating via a filament transformer on variac and pulling it through.

I have seen a video or 2 of people using this method, and it worked rather well, does 28 gauge sound about right?

https://www.youtube.com/watch?v=pHtgBbdJNqo

LED upgrade complete!

:thmbsp:

https://www.youtube.com/watch?v=J1Iu4QmVs9w
getting closer to done.

I have also noticed that I can't bring the picture into full focus, I'm at the max I cant adjust the focus coil and it's the best it can get, the 66m seems OK at about 70m and the 2w 4.7m load resistor to the focus grid seems fine as well, so I'm pretty sure the selenium focus diode is tired, but I don't wanna put another one like it in there.

I have 10 cheapy 20KV 5mA HV High Voltage Rectifier Diodes I'm pretty sure that 2 in parallel should be more than enough to handle it.

original focus diode specs

ECG503(NTE503)/RCA # SK3068
PRV: 14,400 Volts (No Load)
Forward Current IF: 0.5mA
Forward Voltage Drop VF: 260V @ 2.5.mA


i have 10 of these
Rectifier 2CL77

https://digchip.com/datasheets/parts/datasheet/142/2CL77-pdf.php

it SHOULD work IMOH, :D

I can already tell that convergence is going to be a pain in the ass on this set, even though I'm going to have to pull all things off the CRT for safety's sake when I attempt the cataract repair, I have already tried convergence a few times to see how it's going to behave.

First off, I DO NOT like the convergence clover on this set, it sits way too loose on the neck, held in place by spring clamps, way too easy to shift it's position when you try to turn the static adjustment magnets,(discs) which are in an awkward position and hard to turn, I might try to lube them up a bit to make them glide a bit better.

The dynamic convergence is showing signs of trouble, this is not unexpected as I have not gone over the convergence PCB yet, I fully expect the diode array to be tired and out of spec, have already ordered a replacement NTE120, would not be surprised to find worn resistors, just know I'm seeing the same type of non linearity that can't quite be adjusted out that I have seen before when there are parts worn on the convergence PCB. :(

The old focus rectifier was replaced this weekend by 4 of the cheepy 20kv diodes, 2 in series , in parallel, seems to be holding up OK, and made a slight improvement in focus range.

X-ray hazard or hyped up scare?

I have run this set a few times now w/o any problems, but have noticed the FBT gets slightly warm, not TOO hot, but warm to the touch after it's off. (slight smell of warm corona dope. :P )
Right now the cover to the HV box is removed, I'm thinking of keeping it of like I have in my GE set, because I have found that if I place a fan right in front (120mm), then it has a drastic improvement on cooling, I felt NO warmth at all after running it for quite some time.

So I have to wonder, is the unshielded X-ray risk from the 3A3C/6BK4C really that big a deal?
Were they just being overly cautious? By leaving it off one is not going to end up like Zaphod Beeblebrox or something 2 heads & 3 arms?:yikes:

Inquiring minds want to know!:D

The high voltage rectifier should not be a significant source of x-rays as far as I can figure - The voltage across it is low when it's conducting and high when it's not conducting.

The high voltage regulator, however, has high voltage on it while conducting. If all the elements are aligned well, the internal elements provide quite a bit of shielding; the scare started with tubes that were improperly constructed. If no one is going to be below the bottom of the regulator, and you keep some distance, it's probably OK. The caution I would add is that I don't know how to differentiate between a proper and improper tube by eye.

Remember that the danger is cumulative increase in the risk of cancer. There is no particular threshold of safe/not safe. That's why the dental technician steps out of the room to press the X-ray button, not because of immediate effects. In the same way, TV X-ray limits were set so that no consumer could get a significant increase in radiation dosage from them in a lifetime. But techs were expected to heed warning labels when they opened a set.

http://www.nj7p.org/Tubes/PDFs/Frank/107-Sylvania/6BK4C.pdf

It has a warning about "close range" ,not sure how to define that. :o

The set has a 6bk4c vs a 6bk4b as it was built for, which is an improvement.
And it's pointed backwards horizontally in it's own section at the top of the HV box.
Much like the CTC-16(XL), which has it mounted vertically behind the HV box also walled in it's own section with no top, oddly enough.

So the way I sort of see it, using the improved tubes over what was originally designed, 3A3A->3A3C & 6Bk4B → 6Bk4C, any risk should be minimal, for instance what is the difference in this situation with the shunt top open facing backwards ( back on set ), and the CTC-16 line with it pointing up?

Perhaps... don't sit on top of a CTC-16, or you will glow in the dark! :):D :no:

I remember an urban legend that surfaced when they were having problems with these shunt regulator tubes. The story goes that a woman had a cat which liked to nap under the new console color TV because it was warm. After a while, the cat started losing its fur. The vet diagnosed radiation exposure. The woman complained to the TV dealer who escalated the problem higher up until the radiation was measured underneath the console and found to be excessive.

Moral of the story: Don't let your cat nap under your console color TV.

The X-rays don't come out the top of the tube, they come out the bottom. The limits for complete sets with shielding in place were tested at the outer surface of the cabinet. If you look at the regulations for TV sets, and compare the intensity in a complete set to the value from the tube itself you will get some idea, but note that the tests are done with the set deliberately run to maximize X-rays.

https://www.fda.gov/radiation-emitting-products/resources-you-radiation-emitting-products/television-radiation#:~:text=A%20Federal%20standard%20limitin g%20x,manufactured%20after%20January%2015%2C%20197 0.

"A Federal standard limiting x-ray emissions from TV receivers to 0.5 milliroentgen per hour (mR/hr) was issued on December 25, 1969. The standard is applicable to all TV sets manufactured after January 15, 1970. The overall effect of the standard is to require that TV receivers must not emit x-radiation above the 0.5 mR/hr level when tested under adverse operating conditions. Test conditions do not represent normal use and ensure that when used under normal conditions, TV sets do not pose a radiation hazard."

I believe the big cup at the bottom of the 6BK4B is the added shielding.

https://radiomann.sakura.ne.jp/HomePageVT/G_TVHV/6BK4-Syl-A-Hit-B-Mat_1iD.jpg

i also found this out there :P

https://tinyurl.com/3vh2v5zb

the NTE120 Selenium Rectifier for Convergence SHOULD be here Fri, and I'm hoping it will clear up the odd problems I'm seeing..
Right now I can't even adjust R/G horz/vert Left, I turn the pots, and nothing happens :(

I've gotten away with using 1N4007s for convergence rectifiers, though I now stock shottkeys for the task.

This is what is telling me it HAS TO be the selenium diode pack.

http://suzaku.live-evil.org/hoffddd.jpg
Pin 8 goes directly to the pulse winding of the FBT, and I know the 320v signal has to be there because those horizontal pulses are vital to burst amp / color killer / chroma bandpass, and color is perfect.
R25 R28 R227 R228 OK, so X7 it is!

I've gotten away with using 1N4007s for convergence rectifiers, though I now stock shottkeys for the task.

if i was not able to find these so easily, that IS what I would do too! :D :yes:

https://www.amazon.com/dp/B008UTWAG0?psc=1&ref=ppx_yo2ov_dt_b_product_details

new part installed in convergence PCB.

https://www.youtube.com/watch?v=tsiwjEj02I4

i will do at least 1 more pass to tighten it up.

As you may have noticed from the videos posted, I have decided NOT TO attempt the cataract repair on this CRT at this time, the deciding factor was the broken pin 12, and the pure luck I had soldering a thin copper wire back into where it used to go, I want to do absolutely nothing to disturb it until I have something to replace it with.

Right now, the cataract is noticeable, but tolerable, next tax refund, I will highly likely hit ETF up for one of many they have in stock that will fit ( 25AJP22 25BAP22 25UP22 23VBAP22) and so on, and put it in, and THEN try to fix the cataract, and if successful, keep it as a reserve, if unsuccessful, no HUGE loss, I'd be on the new one from ETF.

But as it is now, I was lucky to patch it up and get it working and not willing to roll the dice on cataract repair in the state that it's in.

2nd convergence pass done.

https://www.youtube.com/watch?v=ZtVrJK2JkH0

I have pretty much done all I can with this set in the state it's in, the CRT is in noticeably used state, what I call a “fair” or just above fair condition.
Still hope to try to get an NOS 23 inch at the start of next year, though shipping from ETF will be brutal, but this set is worth it, ( still waiting to hear back from them.)

The convergence repair went perfectly, the 2nd pass went through the normal round robin adjusting of static center R/G/B and R/G horz top/bot, which upset static center R/G, and thus changed R/G horz top/bot, you know the drill!
After about 30+ min of going round and round like this, things were so close that I no longer had to rotate the magnet discs to get the center to line up, just shift them ever so slightly.
There is still some minor nonlinearity in the dynamic convergence, but no where near as bad as when I started.

There is some minor shadowing of the video, the IF may be a bit off, but I'm not gonna worry about that much right now.

more pix
http://suzaku.live-evil.org/rocky-1.jpg
http://suzaku.live-evil.org/rocky-2.jpg
http://suzaku.live-evil.org/rocky-3.jpg


this time a pro made DVD. :O

:thmbsp:
I'd say the green edges add something special to that show.

:thmbsp:
I'd say the green edges add something special to that show.

I know :sigh: :tears:, but as mentioned above, I don't wanna risk the weak repair on pin 12 by removing the CRT + Cataract removal unless I have another tube to fall back on. :/
If it was not for that broken pin, I would have fixed the green gunk by now. :yes:

Patience. Unless you must move it out for some reason, you may find a replacement tube.

I'm kinda on the fence here, should I try the edi solid-tube r-3ds3 in the set, or stay with the 3A3C that's working in it now?

The r-3ds3 was not really made for this set, but should work (guess) as 1 of the 3 cathode pins does match up, pin 2 the others go nowhere, 6,8.
https://www.datasheets360.com/pdf/8329566707472946635

This is the only info I can find, not exactly for the edi, but I'm sure all r-3ds3 tubes are the same.
So, on one hand, the 3A3C is working OK, but on the other, using the r-3ds3 will lower the load on the FBT/HOT cathode. Choices, choices...

Well, I tried the EDI Solid-Tube R-3DS3 for a few moments, and it did not catch on fire, ran it for 5 min, it did not even get warm.

will try to run it longer.

Which is odd now, that the SK3756/508 version fried in 90 sec in my other set.
tube seen here.
(https://www.ebay.com/itm/284317947319)

The EDI Solid-Tube R-3DS3... FAILED! :tears: :thumbsdn:

After about 2 hours of total combined test runs, started to lose brightness and horizontal width, removed it, it was slightly warm at the base, and put the glass 3A3C back in, and all was back to normal.

Guess ya just can't trust any solid HV rect in a color set. :no:

compromise to leaving the HV cage cover off.

http://suzaku.live-evil.org/0917221801a.jpg

Fan will be paced on the back cover.

The power switch in this thing is staring to annoy me.

I have N0 IDEA why the hell they did this, as is was redundant and just causing problems as the contacts are burned due to the 300+v.
cleaning does not help for long, it looses brightness and width, rapid on/off brings it back.

http://suzaku.live-evil.org/hoff-switch.jpg

will most likely bypass it.

If you haven't disabled instant on then you will if you short the B+ power switch.
I think the idea of the B+ switch was to keep the B+ off when the set was turned off to the instant on state...it would reduce power consumption when "off" and prevent the set being in a state where the sweep oscs weren't running but the outputs had power and could potentially draw excessive current.

If you don’t want to disable the instant on / vacation function, perhaps a capacitor across the B+ switch would reduce the contact degradation. :scratch2:

jr

I would disable the instant-on function and be done with it. This was incorporated in color TV sets of the 1970s as an energy-saving feature (remember all the hubbub over energy conservation, not to mention the so-called energy crisis, in those days?) and practically eliminated warm-up time in TVs of the time; just flip the power switch and the picture came on almost instantly. The electricity savings could be debatable, however, since the TV's tube filaments were left on constantly, with only the B+ voltages being removed from the tubes when the set was switched off. Most TVs having instant-on had a defeat switch, either on the front panel or on the chassis rear apron so the feature could be disabled if desired, say if the TV was not to be used for an extended length of time (if the owner were on vacation, for instance, and did not want to leave the set plugged in).

If the instant-on diode, which was connected directly across the TV's main power switch, would short for any reason (say a lightning strike near the power line serving the TV), the set would remain on, regardless of whether the power switch was on or off. TVs which had this kind of damage were usually restored to normal operation simply by removing the shorted instant-on diode; however, this permanently disabled the instant-on feature, if the diode was not replaced.

the "vacation switch" is in the off setting on this thing, I am not a big fan of the instant-on feature in the first place, as it tends to drastically shorten tube life, especially the CRT, but from what I have seen from other "instant-on" setups, is it not the trend to have the filaments on at like 50-60% or so and then power up to full when turned on?

But it seems that THIS set has them on full blast.

but in this annoyance, I will just get rid of the switch on the secondary side, and use the one on the primary.

Note that the primary of the power transformer is switched to a different tap in instant on mode when the power switch is off, to reduce the heater voltage.

jr

That's where the SAMs info is a bit confusing, it lists no info on the 2 taps on the primary winding.

PRI 117V AC @ 3,15A, SEC.1 315V AC @.47A , SEC.2 6.3V AC @ 1.85A, SEC.3 6.3V AC @ 11.4A.

One would think that the info on the omitted primary tap would be for 150V or more to cause the heaters to run at a low enough state at “instant on.” :O

That's where the SAMs info is a bit confusing, it lists no info on the 2 taps on the primary winding.

PRI 117V AC @ 3,15A, SEC.1 315V AC @.47A , SEC.2 6.3V AC @ 1.85A, SEC.3 6.3V AC @ 11.4A.

One would think that the info on the omitted primary tap would be for 150V or more to cause the heaters to run at a low enough state at “instant on.” :O

Wouldn’t have been the first time that SAMs omitted an important piece of data. :D

jr

Cataract repair complete!

http://suzaku.live-evil.org/1008221106b.jpg
http://suzaku.live-evil.org/1008221132.jpg
http://suzaku.live-evil.org/1008221137.jpg
http://suzaku.live-evil.org/1008221147.jpg
http://suzaku.live-evil.org/1008221137a.jpg
http://suzaku.live-evil.org/1008221522b.jpg
http://suzaku.live-evil.org/1008221541.jpg
http://suzaku.live-evil.org/1008221556.jpg

https://www.youtube.com/watch?v=PblT6q0aQOc

cleaning the crap off the safety glass took much MUCH longer than it did to get it off the screen with the hot wire. :scratch2::tears:

Nice work.

TV now n final location.

https://www.youtube.com/watch?v=Wj0a2_-IFVY

It looks good, but I can't stand the Communist News Network.

It looks good, but I can't stand the Communist News Network.

Its one of the FEW things i can show that wont get a u-tube copyright hit T_T.

I did try to put in a NOS 6BK4C, but it FAILED fantastically, throwing sparks as soon as I powered it up, the grid exploded and fried a resistor.

so I'm back on the old smoky glass tube.

http://suzaku.live-evil.org/1015220040.jpg

Here is a reminder as why one should never trust weird no-named electrolytic capacitors.
This is out of a dead 6 year old LCD monitor. A ( TAICON) branded part.


http://suzaku.live-evil.org/1117222242.jpg

they don't make em like the used to! :)

Preaching to the choir here of course, but all the more reason to test components before using them. This is a note to myself as well. I have the equipment; I need to use it.

Thanks.

Preaching to the choir here of course, but all the more reason to test components before using them. This is a note to myself as well. I have the equipment; I need to use it.

Thanks.

My rule is if it's a used part check it...I typically only use used on stuff I don't care about. New never installed parts if I'm familiar with the brand I typically don't check.

it WAS a new part at one time, but hardly lasted 2 years b4 it went to crap, point is, there are STILL fake parts out there :O

The set is starting to act up a bit already, not sure why, not sure if its cause the CRT is on it's last legs, or perhaps that bad 6BK4C damaged something, I swear I saw some smoke, but could not find the source.

But right now, brightness is inconstant, tends to change a lot, but the blue gun is the weakest, AND pin 11 was broken off, and is hanging on by a thread.

So before I do something crazy like try and find a new tube and pay insane shipping charges, OR , work some kind of bodgetastic miracle and fit the 25Vxx22 in this TV from the RCA CTC-90 that I hate! ( only 1.681 inches wider, super glue fixes everything! )

Gonna replace a few more stuff.
http://suzaku.live-evil.org/hoff-hv111.jpg

X5 with a pair of https://www.mouser.com/ProductDetail/78-BY228-15-TAP in series.
I don't like the look of the selenium rectifier in there now, and it's kinda smelly, so boost may be low or unstable, causing me to turn crt bias up, that will be the first thing replaced.
also, R139,,140,141,142. with new 10kv w1 rated parts.

Not sure if this will help anything at all, as the picture tube is clearly a weak point, and every time it's touched is a risk, but not much I can do, as replacements are so far away, :sigh:

If a selenium is making smell it's gone bad.

Keep an eye out for junk 70s SS sets with delta gun 23VxxxP22 CRTs. They show up a lot out here (I'd bet there's still tons in Texas it you keep your eyes open) and the tubes are typically drop in bolt in replacements with the advantage of black matrix technology.

http://suzaku.live-evil.org/0303232312.jpg
this is what I mean by I don't like the look of the boost selenium rectifier, it seems rater cooked!

that 100k resistor looks rather toasted as well.


http://suzaku.live-evil.org/0303232315.jpg

I am 1/2 serious however, there IS room to fit a 25v in there :scratch2:
it would take some serious mods, and it would lose some on the sides, but it COULD fit.

it just depends on how much trouble this gives me, and if another tube ever shows up in the area here.

Update worked!

https://www.youtube.com/watch?v=Dt13mz-tRCQ

I was able to turn CRT bias way down after replacing that ugly diode, and screens came up by quite a bit, but of course, this DID change the vertical linearity a bit, which in turn upset the convergence, this was not unexpected, but over all, things seem better, I will re-do the convergence for the 1000th time at a later date :) :D

Congratulations. This reminds me of the first roundy I got in college....That Silvertone RCA clone fought me... First power up had raster, but after recap it was dead. Damper had shorted, but it tested good before it shorted and I gave up on it for a few months before another set with the same tube had intermittent shorting, I borrowed the presumed good Silvertone tube and it killed the other set..
After that I got HV back but had no raster, and only got light for a split second on power off. After a bunch of tracing I found the selenium boost diode dead and that got me raster.... Somewhere in there I learned that set would eat dampers like candy if the horizontal osc was far enough out of adjustment, and had other problems along the way....It's the fighters that teach you the most.

...It's the fighters that teach you the most.
Yeah. I had a fighter that was kicking my butt royally. Maggie 25", hybrid chassis with transistor IF strip. No luma signal whatsoever, but chroma was unattenuated. Gotta be H-K short in the CRT or dirty service switch, easy peasy. But it wasn't. Chroma subcarrier was coming out of the video detector OK, but no luma. Replaced the diode but no diff. Can't be IF related or the chroma would be gone too, right? Wrong. Finally found the 2nd IF transistor was open. Replaced it, and prollem fixed.

http://suzaku.live-evil.org/0304232245.jpg

it was certainly in a Princess Bride state, as in being " Mostly dead", it was not completely shorted, but WAY below the level it should have been working at. :O

http://suzaku.live-evil.org/0310232247.jpg

after touching up the convergence last night, the picture looked a bit, gamey! :D