http://suzaku.live-evil.org/340111391_6096089680475618_2152504603371490114_n.j pg
http://suzaku.live-evil.org/339738280_6017729581644573_5928032216830327671_n.j pg


I don't have it yet, but will try to get it, it's a bit far away however, about 100 miles. :(

This is a WEIRD one, been looking at the SAMS for a while, trying to make sense of it, not easy, it seems to be a hodge podge several makers, quite a bit of it is reminiscent of the Motorola_ts-907, including the use of 6HS8 for AGC , and dual horizontal outputs. :O
Color demod/amp is NOT RCA, it seems, using a compact tube 6LE8.

The CRT it seems is of the same type as used in my Hoffman Colorcaster, 23EGP22 (25SP22) (25GP22) (25AP22A) state of tube, unknown.

Hopefully I can get this one, and it looks to be a weird one!

I believe that's a remote set. Looks like the transmitter "hanger" in front of the speaker grille, also, the "S" in the model number may stand for "Sonar", Admirals name for their remote systems.

http://suzaku.live-evil.org/340111391_6096089680475618_2152504603371490114_n.j pg
http://suzaku.live-evil.org/339738280_6017729581644573_5928032216830327671_n.j pg


I don't have it yet, but will try to get it, it's a bit far away however, about 100 miles. :(

This is a WEIRD one, been looking at the SAMS for a while, trying to make sense of it, not easy, it seems to be a hodge podge several makers, quite a bit of it is reminiscent of the Motorola_ts-907, including the use of 6HS8 for AGC , and dual horizontal outputs. :O
Color demod/amp is NOT RCA, it seems, using a compact tube 6LE8.

The CRT it seems is of the same type as used in my Hoffman Colorcaster, 23EGP22 (25SP22) (25GP22) (25AP22A) state of tube, unknown.

Hopefully I can get this one, and it looks to be a weird one!
It's probably a G13 chassis. If it doesn't use a HV regulator, it was hard on flybacks. When replacing the flyback, Admiral recommended using one 6DK6 instead of the two 6JM6's.
If it has a 6BK4, it's a H12, which is doubtful!
IDK where they got that 6LE8 color demod circuit from. Many firms used it, not just Motorola. :scratch2:

It's probably a G13 chassis. If it doesn't use a HV regulator, it was hard on flybacks. When replacing the flyback, Admiral recommended using one 6DK6 instead of the two 6JM6's.
If it has a 6BK4, it's a H12, which is doubtful!
IDK where they got that 6LE8 color demod circuit from. Many firms used it, not just Motorola. :scratch2:

Correct, the schematic shows no shunt regulator circuit, they seem to be going about it in an odd way, using pulses from a separate winding on the FBT via a diode and pot to try and tamp down the signal on the grid of the horizontal output, not very effective I would think, that diode will degrade over time being hit with those horizontal pulses.

If its still got 2 HO tubes the FBT is original. The G13 & H12
had a massive FBT kit with tons of mods. If you knew one was in
line to do you called in sick & stayed home sucking down
Schlitz !
BTW if it has a 6EW6 vid amp change it ever few yrs. They get
weak & the details get lost, looks cartoonish. A fresh one brings
back things like hair, freckles etc.

73 Zeno:smoke:
LFOD !

If its still got 2 HO tubes the FBT is original. The G13 & H12
had a massive FBT kit with tons of mods. If you knew one was in
line to do you called in sick & stayed home sucking down
Schlitz !
BTW if it has a 6EW6 vid amp change it ever few yrs. They get
weak & the details get lost, looks cartoonish. A fresh one brings
back things like hair, freckles etc.

73 Zeno:smoke:
LFOD !
It reminds me of that lousy Magnavox hybrid 19" portable. The flyback kit came with a whole mess of components. It was like you had to re-engineer the entire set, change the HV rectifier to a trippler and change resistors and install diodes in some of the other circuits. Then people couldn't understand why I hated Magnavox products! :nono:

How on earth did RCA, etc get away with one horz output, but others needed two?

How on earth did RCA, etc get away with one horz output, but others needed two?

They ran the single tube with minimal 'headroom'. Like if the cathode current was running 220 ma instead of 210, the difference could shorten longevity bigly.

OK..
Awful news
It's already gone.
I was chatting with the owner last night, and it seems he did not know it was already sold. :(

"I have it in a little thrift store at that address and I reached out her this morning and she sold it last night.. Sorry."

SUCKS

Wasted $22 on a SAMS :/

good news (i hope) found another set in the same area.

Que the dramatic music... it's a magnet box!
http://suzaku.live-evil.org/329214014_5996972510360254_6310908628613604721_n.j pg

http://suzaku.live-evil.org/332119497_5916454771742655_5558289039044008980_n.j pg

I see cataract!
RCA style bonded safety glass it looks like.

I don't know much about it yet, hopefully THIS one won't be sold out from under me :tears:

OK..
Awful news
It's already gone.
I was chatting with the owner last night, and it seems he did not know it was already sold. :(

"I have it in a little thrift store at that address and I reached out her this morning and she sold it last night.. Sorry."

SUCKS

Wasted $22 on a SAMS :/

good news (i hope) found another set in the same area.

Que the dramatic music... it's a magnet box!
http://suzaku.live-evil.org/329214014_5996972510360254_6310908628613604721_n.j pg

http://suzaku.live-evil.org/332119497_5916454771742655_5558289039044008980_n.j pg

I see cataract!
RCA style bonded safety glass it looks like.

I don't know much about it yet, hopefully THIS one won't be sold out from under me :tears:

Yikes. I had something similar happen last year. I found a nice Motorola 23EGP22 set on Facebook marketplace (I really want and have been searching several years a first gen rectangular set both for history and to know how bad they really are) and they tell me too late we turned it over to an estate sale company. I contacted the company and worked out a deal and those utter morons sold it much cheaper to fellow collector Paul Abernathy because they "thought he was me". Took me a while to get over the frustration of a let down like that at the end of over a month of chasing it.

I have never seen a stand alone TV console from Magnavox that new in that form factor that wasn't a combo. That thing has to be a rare cabinet.

BTW I have a almost complete Sam's library (up to ~1979) if you want a some phone pics or maybe a small format scan of something to see if it's interesting you can message me before buying it from scam's technical publishing...

Also, I have much of the tuner subchassis from a similar set. (When I found it , it had an 80s LED channel readout Zenith System 3 where the CRT and main chassis used to be so I took the only tube stuff left)

The worst thing about it is, whoever DID get it will most likely commit “The Ultimate Sin” with it, and I don't mean Ozzy's 4th album! :(

Wow thats one odd ball Maggy. Probably is an RCA jug.

It reminds me of that lousy Magnavox hybrid 19" portable. The flyback kit came with a whole mess of components. It was like you had to re-engineer the entire set, change the HV rectifier to a trippler and change resistors and install diodes in some of the other circuits. Then people couldn't understand why I hated Magnavox products! :nono:

I did 2 of them. The whole set was a DOG. I hated them. Glad they didnt build many of them !

Zeno:smoke:
LFOD !

The cabinet is definitely ornate, that's for sure. And the layout is odd as well, with low chassis under the CRT, and tuner way above, perhaps on a sub-chassis.
Seller had it listed as TV/ Radio combo, but can see no sign of a radio in the pics, will know for sure when I see it.

Bit more info.
Been trying to find something about the set.

Found...
Thank you for the inquiry. Color unit built 1963-1964 in Plant #2, Greeneville, TN. Apparently it was not a popular seller.
Hope this helps.
Best Regards,

Magnavox Historical Preservation Association

Bit more info.
Been trying to find something about the set.

Found...
Thank you for the inquiry. Color unit built 1963-1964 in Plant #2, Greeneville, TN. Apparently it was not a popular seller.
Hope this helps.
Best Regards,

Magnavox Historical Preservation Association

It couldn't have been built in 1963. The Motorola 23EGP22 the first rectangular color CRT didn't come out until around 1965.

It couldn't have been built in 1963. The Motorola 23EGP22 the first rectangular color CRT didn't come out until around 1965.

Weirder and weirder, if this set is even confusing an expert from the Magnavox Historical Preservation Association! :D:scratch2:

1967-68 brochure

1967-68 brochure

don't see a pic. :O

Sorry, it won't let me, says I need to resize it, never had to before.

Sorry, it won't let me, says I need to resize it, never had to before.

:tears: wahh! i wanna see, cause this is a weird one!

:yes:

I'll try again tomorrow. The brochure says it's model 6996 without remote for 698.50, or model 6997 with remote for 798.50. Measurements are 32.5 inches wide, 21 inches deep, and 36.5 inches tall.

How on earth did RCA, etc get away with one horz output, but others needed two?

Everyone else is like me, and how I live my life. RCA did cheap and easy. I am like Zenith, do it well, do it right, take no shortcuts. 100% opposite. I live my life like Zenith. I go my own way, no shortcuts. I take my own path, with 100% integrity in good design engineering. I do it the hard way every time. I am who I am. Respect this. I respect you, or I flat out don't care! :tresbon:

How on earth did RCA, etc get away with one horz output, but others needed two?

simple math

2 x 6JM6 tubes, at 17 watts each, which were most likely older tubes most likely BW tvs, or 1 6KD6 at 33 watts. which was made for color sets.

simple math

2 x 6JM6 tubes, at 17 watts each, which were most likely older tubes most likely BW tvs, or 1 6KD6 at 33 watts. which was made for color sets.
RCA came out with the 6LQ6 to replace the 6JE6. Later, they came out with the 6ME6, which was a real bomber! :thmbsp:

I do remember my grandma’s CTC-38 had an appetite for horizontal output tubes. Maybe by design…

That Magnavox is probably a T933 chassis, a vast improvement over the earlier rectangular color chassis U904, U920, T931.

What a strange cabinet, must have been special order to fit at the right spot in the customer's home.

That Magnavox is probably a T933 chassis, a vast improvement over the earlier rectangular color chassis U904, U920, T931.

What a strange cabinet, must have been special order to fit at the right spot in the customer's home.

If so, would make it SAMS folder 1005-1.

Ive seen those, part of a living room setting, a weird regional thing. T940 chassis maybe

Things seem to be on track to pick the set up this weekend, had to abandon last week's attempt due to way too much rain over the weekend. :(

I GOT IT!!!


http://suzaku.live-evil.org/0521232104.jpg UGLY cataract.. RCA style!
http://suzaku.live-evil.org/0521231638a.jpg neat speakers!

http://suzaku.live-evil.org/0521231638b.jpg Houston we have a T933 chassis

http://suzaku.live-evil.org/0521232104a.jpg wired up for test, got no emissions at first, WAKE UP!!

http://suzaku.live-evil.org/0521232106a.jpg 20 MIN later.
http://suzaku.live-evil.org/0521232107b.jpg found this this thing on the bottom of the cabinet, where did THAT come from :scratch2:

http://suzaku.live-evil.org/0521232108.jpg Who stole the tuner cover!?!?!

more later!

I recently restored a Magnavox T931, which is very similar to the T933. I think the T933 added horizontal centering circuitry and maybe horizontal size controls. Instead of using DC restoration via a diode clamper, Magnavox used partial DC coupling of the DC bias from the video detector. This makes the brightness less consistent than what you get with a diode clamper DC restoration design, but it is better than nothing.

The TV’s focus coil is a bit weird too. It can be locked into position, and unlocking it is sometimes a challenge. I wish they just kept it a normal screw type adjustment slug transformer. I am curious to see the state of your T933’s flyback.

If at any point you give up on that TV, I am interested in buying spare parts for my Magnavox. I need a replacement “clover” style dynamic convergence assembly, as mine is cracked due to over tightening. So I’d be interested in buying parts from you.

Just placed a order for a bunch of electrolytic capacitors for the set, as I'm sure they are no good as always.

The flyback transformer looks clean, shockingly clean, TOO CLEAN almost, it has had an easy life, or has been replaced, never seen one this nice before.
http://suzaku.live-evil.org/0522230602a.jpg

This is obviously a custom cabinet, because one dumb thing about it, there is no room to get to and open the side cover on the HV box w/o swinging the chassis out for room.

Another thing that was noticed was, all the screen controls were turned all the way up almost, this does not match with the rather decent emissions that were shown with the CRT tester, meaning some fault with the chassis to be worked out, likely a weak selenium boost rectifier like I had in the Hoffman Colorcaster, or some other fault in the CRT circuitry.

My T931 had screen cranked even though CRT emissions was good. It turned out that the horizontal blanker tube V19 (6GH8A) (http://www.videokarma.org/showthread.php?t=275476&page=4) was tired, and when that tube gets tired the DC bias of the picture tube G1 anodes becomes very low. So you should try swapping that blanker tube for one that is know to be good.

In fact, the only low emissions tubes in my T931 were the three 6GH8A tubes. Chroma demod didn’t work until I replaced the 6GH8A that was used for the chroma oscillator. The T933 chassis is almost identical, so consider swapping those 3 6GH8A tubes out for NOS.

All of the electrolytics were still within spec too, except the two on the convergence control board.

My T931’s flyback looks great too. I think it is due to the fact that the horizontal efficiency coil was tuned for absolute minimum horizontal output tube cathode current. Tuning that coil doesn’t just decrease wear of the HOT, since the HOT is in series with the flyback transformer, that coil’s tuning decreases the wear and tear of the flyback transformer.

http://suzaku.live-evil.org/0522231939.jpg

Very very dirty chassis, and smells of smoke, (tobacco)

http://suzaku.live-evil.org/0522232147.jpg
much better!

not gonna even try to power it up till the weekend, it will have plenty of time to dry.

Some of the coils are made out of magnet wire wrapped around a cardboard cylinder. Won’t water damage them?

Some of the coils are made out of magnet wire wrapped around a cardboard cylinder. Won’t water damage them?

No, the paper types are impregnated with a high temp substance that makes them water proof, just don't use harsh cleaners on them.

http://suzaku.live-evil.org/0523230557.jpg

you can see it in this bad coil from a BW set, it's sealed with some sort of enamel material.

I did my t933 some years ago. I also had the blanker tube make the picture tube look bad. Over the years of owning it the degauss themister/varistor failed, the high meg resistors in the vertical failed and one of the convergence coils on the clover opened up. Mine has all original power supply electrolytics and the original flyback. I adjust the HOT current whenever I replace the output tube. I use it an hour once a week.
They can make a good picture!

The blanker tubes went every few yrs. It may be why the G-2's are high.
TNR shield often missing or hanging loose in Magys. Tuners were constantly dirty
& messy techs just tossed them. Maggy even tried tuner pads, no joy. Dont
remember who built them but they were in other sets & didnt have problems.
Go figure:scratch2:
Part you found looks like its part of a coil form with the slug.
Look on the CONV panel.

73 Zeno:smoke:
LFOD !

The blanker tubes went every few yrs. It may be why the G-2's are high.
TNR shield often missing or hanging loose in Magys. Tuners were constantly dirty
& messy techs just tossed them. Maggy even tried tuner pads, no joy. Dont
remember who built them but they were in other sets & didnt have problems.
Go figure:scratch2:
Part you found looks like its part of a coil form with the slug.
Look on the CONV panel.

73 Zeno:smoke:
LFOD !

Correct, that mystery broken coil part does look like it is from the convergence PCB, but all of them are intact! :thmbsp:
one must have been broken and replaced in the past, no telling HOW LONG that piece has been in there!

DAMN! there is NO ROOM to reach under the chassis to change out C1, it's just too tight under there.

DAMN! there is NO ROOM to reach under the chassis to change out C1, it's just too tight under there.

Why did they design the chassis to tilt that capacitor? Was it to tilt it away from the isolation transformer’s heat?

Why did they design the chassis to tilt that capacitor? Was it to tilt it away from the isolation transformer’s heat?

I.m gonna have to do something drastic to replace it, cause I have noise in the B+ line :(

https://www.youtube.com/watch?v=QFl25sRnB0E

many weak tubes
most are still the original.

gonna have to check all the resistors as well

but FIRST video

I GOT IT!!!






\

http://suzaku.live-evil.org/0521232108.jpg Who stole the tuner cover!?!?!

more later!
Those Standard Coil tuners always needed cleaning.
They used to sell a kit that had a special cleaner and lube, plus a foam pad that went on the cover with the lube. After a while, the pad deteriorated and cruded up the tuner more. :thumbsdn:

Yeah, the tuner was very dirty, it was a bitch to get out because of the silly front screw in system they use that you have some odd key to unscrew.
Even after cleaning the contacts for chan 3, had problems getting a clear pic due to what I believe to be tired/ worn tuner tubes, only after hooking in a 15db rf amp was I able to tune in a clear video w/o snow.
Cause as mentioned, it seems that almost every tube is OEM and most likely worn/ tired.
I did try a couple of 6GH8As in the V19 socket ( h-blanker / bandpass) that were of unknown state, the first one made no change in the picture at all, the other must have been VERY bad, cause something smoked as soon as it was turned on, but STILL WORKED when the previous tube was put back, will no doubt find what it was when I check resistors, most likely many will be out of tolerance and need to be replaced.

Tubes ordered so far, based on what was observed, both tuner tubes, video output tube ( the video was being overpowered by color ) and the R-Y B-Y G-Y compactron, what color there was , is very off balance like one of the Y-amps was weak, though this could be bad resistors, but a 50+ year tube can also do it.

As mentioned, C1 is going to be a big pain to replace, C2 C3, are not so bad, but it looks like C1 was put in first, soldered in a very tight area, and then everything else wired in neatly and tightly in layers under it, there is no way to reach the bottom of C1 w/o ripping it all up.

What I may end up doing is attacking C1 with a dremel cutting wheel, won't be pretty but should work, cut around the base remove can and guts, work down to attach 3 new caps using solderable base of old C1 while leaving wiring to it under it undisturbed. ( idea anyway ).

But for now, gonna start with checking resistors on the chroma / luminance board.

Another annoying thing with this TV, is that “Instant On” was enabled, most likely for a very long time, which must have cooked the heck out of these poor old tubes.
Also, not seeing full vertical deflection, and linearity is a tad off, also a sign of bad caps and resistors in the sweep PCB.

I found out why that one 6GH8A made something smoke like it did, I really don't think the getter is supposed to upside down in there like that... it broke off!

Those Standard Coil tuners always needed cleaning.
They used to sell a kit that had a special cleaner and lube, plus a foam pad that went on the cover with the lube. After a while, the pad deteriorated and cruded up the tuner more. :thumbsdn:

Can you post a video and/or more pictures showing how to disassemble a tuner and clean it?

i did find what smoked.
http://suzaku.live-evil.org/smoke11.jpg

R164 went up in value R165 went down. :o

both replaced.

One thing about the PCBs used in this maggie TV, they are much more dense / thick than the ones used in RCA, GE and others I have worked on in the past, example, previously I have been able to take my work light (halogen hand lamp) and point it at the top of the board, and see light through the PCB, along with the shadow of the offending component from the bottom side, but not with this Magnavox :O no light at all gets though the board!

i did find what smoked.
http://suzaku.live-evil.org/smoke11.jpg

R164 went up in value R165 went down. :o

both replaced.

The cause was a short in the tube that causes excessive cathode current?

The cause was a short in the tube that causes excessive cathode current?

Yes, the getter completely come off, stand and all, and was loose in the top, I had not not noticed it, was only on for about 30-40 sec, before i saw smoke and shut it off, resistors may have already been weak, not sure.

Yes, the getter completely come off, stand and all, and was loose in the top, I had not not noticed it, was only on for about 30-40 sec, before i saw smoke and shut it off, resistors may have already been weak, not sure.

Are you sure that the metal getter didn't short the elements in the tube when it was flopping/flopped around? Short between elements might have caused the problem.

Are you sure that the metal getter didn't short the elements in the tube when it was flopping/flopped around? Short between elements might have caused the problem.

I'm sure it did, but it was only on for 30-40 seconds with the bad tube, how fast do resistors fry?
There was also heat marks on the PCB under these 2 parts already, I suspect they were already on the way out, and putting in the bad tube did not help it! :P

I'm sure it did, but it was only on for 30-40 seconds with the bad tube, how fast do resistors fry?
There was also heat marks on the PCB under these 2 parts already, I suspect they were already on the way out, and putting in the bad tube did not help it! :P

Half a minute is plenty long enough to fry resistors, given the right (wrong?) set of circumstances.

One thing about the PCBs used in this maggie TV, they are much more dense / thick than the ones used in RCA, GE and others I have worked on in the past, example, previously I have been able to take my work light (halogen hand lamp) and point it at the top of the board, and see light through the PCB, along with the shadow of the offending component from the bottom side, but not with this Magnavox :O no light at all gets though the board!

I noticed that too. I like my T931’s build quality. 2000s solid state TVs have PCBs that are as thin as two sheets of paper.

The one thing I do not lile about the T931 (and the T933 as the same design) is that it doesn’t use DC reinsertion, but instead uses partial DC coupling of the DC bias from the video detector. This causes inconsistent black levels, especially for super bright scenes, which cause black crush.

I am tempted to add a diode clamper to make brightness more consistent between scenes.

Well, all the others in the area seem to check OK, it was most likely being fed by the big 4w resistor on the triode plate P1.

Yeah, the tuner was very dirty, it was a bitch to get out because of the silly front screw in system they use that you have some odd key to unscrew. >>>>

The screws with 2 holes come out with long needle noses. They also
used 2 sizes of inside out nuts. I saw everyone fighting them so called
Maggy FS to get part ##'s & ordered 2 sets. I told the techs if they lost them they will build stands for 60 days:tears:

BTW many sets had a 'lytic on the conv PCB, causes bad V lin. IIRC
this had it ?

Zeno

Yeah, the tuner was very dirty, it was a bitch to get out because of the silly front screw in system they use that you have some odd key to unscrew. >>>>

The screws with 2 holes come out with long needle noses. They also
used 2 sizes of inside out nuts. I saw everyone fighting them so called
Maggy FS to get part ##'s & ordered 2 sets. I told the techs if they lost them they will build stands for 60 days:tears:

BTW many sets had a 'lytic on the conv PCB, causes bad V lin. IIRC
this had it ?

Zeno

It has two lytics on the convergence PCB. They tested bad on my T931, and so I replaced them with 105c lytics.

i replaced them on mine as well.

BOY the new ones are tiny!
http://suzaku.live-evil.org/0525232112a.jpg

also replaced the cap on the contrast pot, i don't think the old one is very good!

http://suzaku.live-evil.org/0525232112.jpg

i replaced them on mine as well.

BOY the new ones are tiny!
http://suzaku.live-evil.org/0525232112a.jpg

also replaced the cap on the contrast pot, i don't think the old one is very good!

http://suzaku.live-evil.org/0525232112.jpg

IIRC my Maggie roundy is still running original lytics on much of the TV chassis (the remote and amp chassis got full recaps) with the exception of the contrast lytics section of a can which was completely open. I just added a new cap at the pot and brought the set from weak unadjustable contrast to plenty of contrast with good adjustability.

The multi lytics in the set are as such.

C1-A&B (80uf@450) are impossible to reach cause of no room, (filters)
C1-C is 20uf @ 350 and may be able to isolate and relocate as it's for the grid of audio output.
C2A 80uf @ 450 filter
C2B 50uf @ 450 filter on vert output
C2C 30uf @ 450 filter
C3A 20uf @ 450 filter bottom of voltage divider
C3B 20uf @ 450 filter video amp 1
C3C 20uf @ 450 audio out xformer

Just can't do anything to C1 w/o destroying it. :no: :tears:

The multi lytics in the set are as such.

C1-A&B (80uf@450) are impossible to reach cause of no room, (filters)
C1-C is 20uf @ 350 and may be able to isolate and relocate as it's for the grid of audio output.
C2A 80uf @ 450 filter
C2B 50uf @ 450 filter on vert output
C2C 30uf @ 450 filter
C3A 20uf @ 450 filter bottom of voltage divider
C3B 20uf @ 450 filter video amp 1
C3C 20uf @ 450 audio out xformer

Just can't do anything to C1 w/o destroying it. :no: :tears:

For my Magnavox T931, I used an oscope to measure the ripple voltage on each lytic that is used as a decoupling capacitor. They all measured good. I also did in-circuit ESR and capacitance tests and all measured good except those 2 on the convergence PCB. I bet after reforming, most are still within specification.

Perhaps they are OK, but I don't know yet, in most sets I have done so far many were bad, C4 was definitely bad and leaky testing a 2x norm value, C5 was also too high @ 81uf, (cathode cap vert output ) , now has new TVA1414-E3 Sprague ATOM.

I don't have one of those old fancy vintage cap leakage testers, wish I did, but from what I have seen, if the testers I DO have (I have 2) show the value to be way WAY above the posted value, chances are it's leaky and not to be trusted, like the example of the 100uf testing a 208 on both testers.

If you want your restoration to look OEM on the inside, you can get newly manufactured multi section can lytics from CE Manufacturing. I bought a new capacitor from them to replace C1, just in case it failed to reform.

Only 2 new tubes have come in so far, the mixer/ osc for the tuner, and the video amp V6 12GN7A, no change in the picture yet, VERY weak luminance that is overpowered by color.

In grayscale setup it does not take much turning up of the screens at all to make a bright line on all 3 guns, but when in normal mode, nothing is seen on the screen cause luminance is so low getting to the CRT. You have to turn the screens up too see anything at all.

3 good 6GH8As are coming, as is the 1st video amp cathode follower tube 6LM8 (V6)
I have not found any other bad resistors so far, hopefully this is just a case of tired tubes, as mentioned, they seem to be all original.

12GN7A tubes are one of the most impressive vacuum tubes to have been mass produced. It has a very impressive gain, and its plate can handle 12 watts. Not bad for such a small tube.

I think the luma issue is due to the weak 6GH8A blanker.

12GN7A tubes are one of the most impressive vacuum tubes to have been mass produced. It has a very impressive gain, and its plate can handle 12 watts. Not bad for such a small tube.

I think the luma issue is due to the weak 6GH8A blanker.

some sources say that 6LM8 and 6GH8A are compatible, but i am getting a new one of each anyway.

The 6GH8 blanker and the 6LM8 video amp really need to be 100% in these chassis. Earlier Magnavoxs did use a 6GH8 in place of the 6LM8s. Also, unlike most all other brands, the brightness control on Magnavoxs has an effect on the set up service line adjustment. I always start with brightness, contrast, and kine bias controls tuned down. After set up and tweeking adjustments, if brightness is lacking check resistor R74, on the cathode of the 12GN7 ( shown on your post number 51). The resistor is usually underneath the tube socket on the foil side of the board. The diagram shows a 470 ohm, some sets used a 270 ohm. On sets needing more brightness range I replaced the 470 with a 270, made quite a difference.

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

2nd video

its pretty clear that the filters are not up to snuff.

http://suzaku.live-evil.org/magg1-cap.jpg

going to try and replace what Caps i can C2a C2c C3a

hopefully that will clear up that noise in the screen ( bar riding up )

USPS is living up to it's reputation of reliability and efficiency as always (heavy sarcasam ), as the new 6MD8, which should have been here today, decided to take a 1,800 mile sightseeing trip from the local PO 15 miles away, to Teterboro NJ, WAY TO GO, USPS!

USPS is living up to it's reputation of reliability and efficiency as always (heavy sarcasam ), as the new 6MD8, which should have been here today, decided to take a 1,800 mile sightseeing trip from the local PO 15 miles away, to Teterboro NJ, WAY TO GO, USPS!

Ya never know, it just might show up today!

Just sharing my frustration a bit with USPS. :D:thumbsdn:
30 May 2023 14:13
Arrived at USPS Regional Origin Facility. Your item arrived at our KEARNY NJ DISTRIBUTION CENTER origin facility on May 30, 2023 at 2:13 pm. The item is currently in transit to the destination. KEARNY NJ DISTRIBUTION CENTER ← Expected Delivery by 5/30/23 by 9pm, I DON'T THINK SO-- USPS!

USPS
29 May 2023 01:12
Arrived at USPS Regional Facility TETERBORO NJ DISTRIBUTION CENTER ← leaving on a jet plane, just for fun?
USPS
28 May 2023 12:58
Arrived at USPS Regional Facility AUSTIN TX DISTRIBUTION CENTER ← 15 miles away
USPS
28 May 2023 12:57
Departed USPS Regional Facility AUSTIN TX DISTRIBUTION CENTER ← it left before it arrived!

USPS
28 May 2023 03:50
Arrived at USPS Regional Facility DALLAS TX LOGISTICS CENTER
USPS
27 May 2023 11:27
Departed USPS Regional Facility CHICAGO IL NETWORK DISTRIBUTION CENTER
USPS
27 May 2023 01:37
Arrived at USPS Regional Origin Facility CHICAGO IL NETWORK DISTRIBUTION CENTER
USPS
26 May 2023 11:49
USPS in possession of item OAK PARK, IL, 60304
USPS
24 May 2023 15:52
Shipping Label Created, USPS Awaiting Item FOREST PARK, IL, 60130

If you think that's bad it's just a part for a hobby...
Our local state farm office was not getting mail into their PO box for MONTHS.... People's coverage was lapsing and their business was a mess because of this. For several months in a row our agent kept pestering them to fix it and getting ignored, the runaround, BSed, all the above until eventually someone noticed they had been dumping checks and sensitive legal documents into the wrong PO box for months! Can you imagine getting into an accident and discovering you don't have coverage because the post office wasn't delivering your check. :yikes:

I get that they are having staffing issues, but at some point there needs to be punishment...If they have to worry about the last 2 months of their paycheck deposits being pulled back from their account or SOMETHING other than layoff that hurts then they'll be more careful.

USPS is not the only carrier to engage in long odysseys. I ordered an A/C hose from Phoenix, AZ. I live in the Atlanta, GA area. Fed Ex Ground routed it through Idaho! Come on guys - just get on I-10 and head due east.

Today, I ordered another car part which is being shipped from a town 7 miles away. DHL says it will be here on Friday. Before you ask, the company won't let me pick it up in person.

I'm just having flashbacks of when I tried to get a NOS vertical block transformer for my Arvin over 2 years ago or so from e-bay, the first one was lost when it got to the local PO, they never found it, the 2nd one was DOA, a bad one, used in a new box, which was lost on the way back RMA, the 3rd and final came from ETF, and I was very nervous tracking it all the way from Hilliard, OH, hoping that USPS would not mess it up as well.

C3 replaced

http://suzaku.live-evil.org/0530232043.jpg
http://suzaku.live-evil.org/0530232044.jpg

C2 is next.

one thing i noticed
most of the time when the set is turned on, there is no luminance at all, brightness cont has no effect, but if I switch it in and out of service mode several times, it will suddenly start working.
weird.


all it does it cut power to IF 1&2 and the pincushion amp.

still waiting for new tubes

"all it does it cut power to IF 1&2 and the pincushion amp."

Are you sure? I thought the service switch usually defeats the brightness adjustment also.

"all it does it cut power to IF 1&2 and the pincushion amp."

Are you sure? I thought the service switch usually defeats the brightness adjustment also.

you would think so, but they seem to do things odd in this one,

http://suzaku.live-evil.org/servi1.jpg

and that one line down goes to power the 12AX7 VIA L48
http://suzaku.live-evil.org/servi2.jpg

First step in greyscale setup is to set brightness, CRT bias & screens full CCW, so it's clear that brightness defeat was left out for some reason.

I just know that for now, it has this odd behavior which may or may no be tied to old tubes, hopefully new IF and 6GH8As, 6LM8 will be here by the weekend w/o a detour across the country like the 6MD8 did.

Will just have to see if they make any change, otherwise there is something very weird going on that I have not seen before.

Symptoms are as mentioned above, MOST of the time, not always.
First cold turn on, no luminance , very dark screen, brightness has no effect at all, but some chroma seen faintly on screen, sound OK.

After about 60-90 sec.
Flip service switch in and out about 5 times a BOOM! Luminance comes to life, and brightness cont now works, however does not have the full contrast it should have.

Weird.

So, you're saying S9 has only the two sections, A and B. Hard to see how it can kill luma without also killing chroma. Definitely weird.

Regarding low contrast, tube color sets rely heavily on adequate gain of the video output tube. For the old Magnavox I had, I bought 5 or 6 video output tubes and swapped them out until I found the highest gain one. It made a big difference.

So, you're saying S9 has only the two sections, A and B. Hard to see how it can kill luma without also killing chroma. Definitely weird.

Regarding low contrast, tube color sets rely heavily on adequate gain of the video output tube. For the old Magnavox I had, I bought 5 or 6 video output tubes and swapped them out until I found the highest gain one. It made a big difference.

The way they have the brightness control is a bit odd, at least I have not seen anything like it before, seems to be some odd feedback loop, it starts from point 30 on the linked schematic above, far side of the 2 peaking coils off the detector, and goes to the bottom of the brightness control pot, right before another peaking coil that feeds G1 of the video output.

c2 Replaced! :D

http://suzaku.live-evil.org/0531232009.jpg

it WAS borderline bad.

i could not cram any more under there if I wanted!
powered up OK, with horz disabled, no smoke!
will have to get some silicone this weekend to tack it all down neatly.
hopefully I can get away with leaving C1 as is, cause i just cant get to it. :sigh:

This maggie seems to have borrowed a bit from the RCA CTC-20 when it comes to the video amps and brightness control, including the cathode follower/ chroma sync amp and what looks like negative feedback loop circuit, where the Hoffman Colorcaster looked closer to a RCA CTC-16 (17 perhaps?)
Can't say which method is better. :/

Will post more schematics tonight.
More tubes are due by the weekend, in the meantime, will check peaking coils, seriously doubt any will be bad.

OK, the brightness control of this TV, something a bit new to me. :P

http://suzaku.live-evil.org/bright-1.jpg

The POT seems to adjust the bias of the grid on the video output V6, this is nothing new, seen it before, but what is new to me is trace 30, http://suzaku.live-evil.org/bright-2.jpg
which feeds in right after the detector and before the delay line line and first video amp and cathode follower, and seems to be some kind of negative feedback circuit i have not seen before in a tube set in the video area.
granted, I have worked mostly with RCA stuff.


on a lighter note one more tube came today, a NOS 100% tested 6GH8A, for the V19 blanker/ banbpass http://suzaku.live-evil.org/0601231819.jpg

just got my nails done today! :D

more tubes will come over the next 2 days, hopefully :yes:

2 more NOS tubes due today 1st & 2nd IF, (6GM6 6JH6), 3rd tomorrow, or so says USPS, as well as the 3 tested “good” used RCA 6GH8As, Tested At 88/88 Or Better, however the NOS 6LM8 won't show till next week. :(

But everything I'm seeing, says that the 6GH8A is a drop in compatible sub for 6LM8, so, since I do now have the one NOS 6GH8A in place at V19 blanker/banpass, new IF tubes, (hopefully), and 3 good tested 6GH8As to try in the meantime while I wait for the NOS 6LM8 cathode follower's place, I should hope to see some improvement I would guess.

OK, the brightness control of this TV, something a bit new to me. :P

http://suzaku.live-evil.org/bright-1.jpg

The POT seems to adjust the bias of the grid on the video output V6, this is nothing new, seen it before, but what is new to me is trace 30, http://suzaku.live-evil.org/bright-2.jpg
which feeds in right after the detector and before the delay line line and first video amp and cathode follower, and seems to be some kind of negative feedback circuit i have not seen before in a tube set in the video area.
granted, I have worked mostly with RCA stuff.


on a lighter note one more tube came today, a NOS 100% tested 6GH8A, for the V19 blanker/ banbpass http://suzaku.live-evil.org/0601231819.jpg

just got my nails done today! :D

more tubes will come over the next 2 days, hopefully :yes:

Brightness in the Magnavox T931 and T933 is just partial DC restoration where the brightness potentiometer controls how partial the DC restoration is. In more detail: the DC bias of the output of the video detector is the DC bias of the video signal, the actual brightness. The pot is used to create a new DC bias that is the average of the actual DC bias off the video detector and a constant DC bias of around 2.5 volts. You want to set cutoff of the CRT using the CRT G2 pots and CRT G1 pots so that you can dial the brightness pot as low as possible because that maximizes the amount of DC coupling of the original video signal’s DC bias, that is, this preserves the actual brightness information of the original video signal. The higher the brightness pot, the less brightness info you keep from the video signal.

slowly getting there

https://www.youtube.com/watch?v=Sd4y_47yX0o

I may have gotten a flaky or bad NOS 12GN7A video output tube, it's that, or there is something off, in that circuit, cause when I put the old tube back, the odd bit about no luminance when first turned on seems to have gone away, not sure, still waiting for the new 6lm8 and ordered yet another 12GN7A.

did have a bit of an accident today :tears:
when trying the tube wiggle test, got my finger caught on the flange on the Drive control PCB, SHOCKING! :yikes:
http://suzaku.live-evil.org/0603231855.jpg

I'm literally putting my blood sweat and tears into this set! :D :yes:
It's not really THAT bad, it's gonna hurt later, but i have it sealed with Cyanoacrylate, cheap and easy something an ER room would charge $300+ to do.

best result yet!
https://www.youtube.com/watch?v=kIqNFMaDMAE

Still have hum bar problem :tears:

may have to cut out and replace C1 after all, and it still had the odd problem of no luminance when first turned on, but after fiddling with it pops on, not sure why it does this yet.

the 6LM8 NOS it still on track to show up on Monday, will have to see if it fixes the strange brightness control problem.

still at a loss at what to do about C1, as replacing C2 & C3 did not get rid of the hum bars.

but as mentioned, there is just no room :(

I may try the unspeakable and do what many say not to do and tack in new caps in parallel to it, and hope it never shorts.

http://suzaku.live-evil.org/magg1-cap.jpg
R219 is very easy to reach and add a cap to, however the point of L56 and the bridge wont be so easy to reach, I have 82uf 500v caps now, but I think that will be a little too much to add in parallel to the existing C1, i was thinking of using 33uF 500v caps.
sound reasonable?

So, for lack of any better idea to try, I will order 2 of these to put in parallel to C1A & C1B this weekend, 661-EKXJ501ELL330MK4.
And hope it helps with the hum bars, if it does not, then there is something else causing it, :(

Due to my unfortunate shocking adventure in protruding electrified edges this weekend, something I've not had the joy of experiencing since High School with a vicious Zenith hybrid, I won't be pulling the chassis for a while in this till it heals a bit. :/

“R219 is very easy to reach and add a cap to, however the point of L56 and the bridge wont be so easy to reach”

Why not add the 82 uf caps downstream, at the circuits that are supplied by the 400 and 390 A sources? :scratch2:

jr

correction: C1 B is on the 270V source not the 390 A source.

“R219 is very easy to reach and add a cap to, however the point of L56 and the bridge wont be so easy to reach”

Why not add the 82 uf caps downstream, at the circuits that are supplied by the 400 and 390 A sources? :scratch2:

jr,


yes, I do have access to R112, the only point that seems to be hooked to 400v can't find the 2nd that is mentioned on the distro chart, won't putting in the 82s w/o being able to reach in and unhook the old C1 cause undue stress on the diodes? or will the termistor dampen this? this was the only reason I was thinking of using 33uf.

“won't putting in the 82s w/o being able to reach in and unhook the old C1 cause undue stress on the diodes?”

I suspect C1 sections are now effectively much less than 80 uf, and wouldn’t worry about the diodes. Also, thermistor should limit inrush current.

jr

“won't putting in the 82s w/o being able to reach in and unhook the old C1 cause undue stress on the diodes?”

I suspect C1 sections are now effectively much less than 80 uf, and wouldn’t worry about the diodes. Also, thermistor should limit inrush current.

jr

will try sat.

http://suzaku.live-evil.org/0605232106a.jpg

best pic so far!
6LM8 NOS did seem to help

found why I was getting such a snowy pic
I am missing a tuner bias!
http://suzaku.live-evil.org/tuner111.jpg
bias source 1 is not there, which powers the RF amp. problem with R240?
in the mean time till i can pull the chassis, i took a 18 ohm resistor and hooked it to the B source 2, and it now has a clear pic.

will try sat.

http://suzaku.live-evil.org/0605232106a.jpg

best pic so far!
6LM8 NOS did seem to help

found why I was getting such a snowy pic
I am missing a tuner bias!
http://suzaku.live-evil.org/tuner111.jpg
bias source 1 is not there, which powers the RF amp. problem with R240?
in the mean time till i can pull the chassis, i took a 18 ohm resistor and hooked it to the B source 2, and it now has a clear pic.

Have you tried substituting a 6GH8A for the 6LM8? I am curious to know which performs best.

Have you tried substituting a 6GH8A for the 6LM8? I am curious to know which performs best.

did not like it at all :P

I found out why I lost B+ source #1 on the tuner. :(

when I was first poking around trying to reach in there to get to C1, I broke R240!

http://suzaku.live-evil.org/0609232225.jpg
it's just so dang packed in there!
it USED to go to that orange wire, you can see C! way down in there.

http://suzaku.live-evil.org/0609232243.jpg

the fix!
all tacked down with silicone

seeing a little bit of color echo/ ringing to the right, mostly on reds.
http://suzaku.live-evil.org/0610231942.jpg
can be seen on the V on their shirts.

have new V20 color demod, and V22 killer burst amp ordered, these are also old original tubes.

Replace that 6GH8 Video blanker tube. It's a common problem with dim pictures on this chassis and several relatives. It's not unusual to see these weak or bad. It makes a major difference in how the set functions. I always replaced weak/bad ones when I was a grunt technician in my younger years.

Replace that 6GH8 Video blanker tube. It's a common problem with dim pictures on this chassis and several relatives. It's not unusual to see these weak or bad. It makes a major difference in how the set functions. I always replaced weak/bad ones when I was a grunt technician in my younger years.

V19 blanker/ bandpass was replaced with a NOS early on when i had weak brightness, but it was the V5 6LM8 that mad a big difference as well.

now I wanna try and clean up the color echo a bit.

All I see is the L blue conv is way off. Otherwise it looks pretty normal
for an aged Maggy. On Maggys there is what we called a "Brownulator"
switch. Turn it OFF if its on. It gives the pix an overall brown to it.
Always turn off any auto color schemes while working on a set.
One last thing is ground lugs. Where the PCB's are soldered to the
steel frame resolder them. Can cause strange int problems on most
brands of TV.

73 Zeno:smoke:
LFOD !

All I see is the L blue conv is way off. Otherwise it looks pretty normal
for an aged Maggy. On Maggys there is what we called a "Brownulator"
switch. Turn it OFF if its on. It gives the pix an overall brown to it.
Always turn off any auto color schemes while working on a set.
One last thing is ground lugs. Where the PCB's are soldered to the
steel frame resolder them. Can cause strange int problems on most
brands of TV.

73 Zeno:smoke:
LFOD !

I'm aware of the convergence issues, have not really tried to mess wit it yet, cause when I pull the CRT later this summer on a 100+ day to try and fix the cataract, the convergence will be messed up all over again! :tears:

Hopefully the new 6MK8 demod tube will clear up the slightly bleedy red, another symptom is, when color pot is turned up all the way, all color is lost, flashes to greenish tone for a bit, then BW. Backing off, color pops back on strong.

Hopefully the new 6MK8 demod tube will clear up the slightly bleedy red, another symptom is, when color pot is turned up all the way, all color is lost, flashes to greenish tone for a bit, then BW. Backing off, color pops back on strong.
The 6MK8 is a selected 6HS8. I had a GE branded one that had the 6HS8 number sand blasted like GE was famous for, but had the 6MK8 number printed on like the logo. :scratch2:
The last Warwick Sears hybrid used a 5MK8.

New tubes did not help the color shadow much, it's still there, chroma bandpass may be slightly off alignment, not much I can do about it, as I don't have the rig to adjust it, fine tuning has no effect on the shadow.

V22 must have been weak, ( color killer/burst amp) 6KE8, because when the new one was put in, color intensity levels were MUCH lower then with the old OEM one, I thought this very strange at first, until I found that the color killer pot R10 had been turned up almost past 2/3s past max, turning it way down got strong colors back with the new tube.

As someone said before, this chassis is picky about tubes, especially the 6GH8As it seems. :O

Can you post a picture of the "color shadow?" I'm not picturing it in my mind.

Can you post a picture of the "color shadow?" I'm not picturing it in my mind.

I will try to get better examples tonight, but you can see it in the V on his vest, a bleed to the right with reds, its there on all colors, but seen most on red.
http://suzaku.live-evil.org/0610231942.jpg

What is the source? If it's a VCR, ignore it, as the poor bandwidth of the tape chroma can mask any effects of the TV alignment.

Source is a Sony DVPSR210P DVD Player, playing videos from blu-ray videos that were converted down to DVD format.

I just happen to like using Lost in Space because of the loud gaudy outfit colors, and it's period correct for the set! :)

pics of color echo

paused DVD lost in space

http://suzaku.live-evil.org/0616232041.jpg

color off
http://suzaku.live-evil.org/0616232042.jpg

pro DVD
Futurama paused
http://suzaku.live-evil.org/0616232047.jpg

http://suzaku.live-evil.org/0616232049.jpg

fine tuning has no effect

fine tuning has no effect

That indicates it's not due to IF misalignment.
So, it could be a misadjusted 4.5 MHz trap or the color bandpass alignment, etc. - something following the video detector.

That's what I thought, where I can adjust the 4.5 MHz trap by eye, but as of yet, I don't yet have the tools to adjust the color bandpass alignment, and I'm not foolish enough to try THAT by eye, cause it would only make it worse. :tears:

I have done all I can do with this Maggie pretty much chassis wise, next step would be CRT cataract repair, I'm still not sure what tube it even has yet, as the number is blocked by the x-ray shield, I just know it's a heat removal type, and it's risky with this tube. :(

All I can say is I like this chassis type the least so far, due to it being so finicky about the tubes you put in it, change any tubes in the color section, and you almost HAVE to go through the color AFC procedure for best results, or keep swapping tubes till you get optimum picture.
Not something I have seen with RCA and clones.

From everything I've seen, this CRT type has the most risk with cataract removal, due to the RCA type of bonded safety glass and the rectangle shape, hot wire method does not work, like on the green gooey Zenith type, unfortunately heat is one of the few things to get it to let go, but can also cause uneven stress on the tube.
It's not like there has not been a lack of very hot days to leave it out in direct sunlight to warm it up, but most likely to get it off a heatgun will be needed, and there is always risk with that no matter what especially with these rectangle tubes. :(

While I wait for a free weekend for my friend to help with the cataract repair, I have been working on the cabinet the best I can, UI have no exp in wood working, so there is little i can do, and there is a nickle sized hole in the veneer on the top i cant fix, but i have done the best i can so far.

http://suzaku.live-evil.org/0628231929.jpg

What fixed the lack of contrast range?

The date is now set for the attempt to fix the cataract which will be next Sunday 7/23.

has anyone else done these rectangle types with the RCA type bonded safety glass before?

it's due to be another 100+ day that day, gonna start by leaving in the blazing sun for a while, but still worried about this one, being a rectangle type.

The date is now set for the attempt to fix the cataract which will be next Sunday 7/23.

has anyone else done these rectangle types with the RCA type bonded safety glass before?

it's due to be another 100+ day that day, gonna start by leaving in the blazing sun for a while, but still worried about this one, being a rectangle type.

I will be watching carefully, this thread. I have an RCA CTC-28 with a weak CRT and a new rebuilt Channel Master CRT... which has cataracts unfortunately. I live in Florida so sun should not be an issue!

now I know the type of tube in the set!

http://suzaku.live-evil.org/0722231253a.jpg

I think the date code is 1969 :o

My original tube is a 25XP22. My replacement is a Channel Master 25AP22 and according to the cross reference, that is the proper sub. Fingers crossed...

Cataract repair successful!!! :banana::D

http://suzaku.live-evil.org/0723231535.jpg
http://suzaku.live-evil.org/0723231648b.jpg

Thus was a LOT easier than expected, after an hour in the sun, and sticking spudgers in under the safety glass, it almost came off on it's own W/O hardly any need of the heat gun.

http://suzaku.live-evil.org/0723231651.jpg
gunk came right off.

http://suzaku.live-evil.org/0723231748.jpg
glass back on
http://suzaku.live-evil.org/0723231916.jpg

tube back in
http://suzaku.live-evil.org/0723232206a.jpg
http://suzaku.live-evil.org/0723232206b.jpg

hard part is over!

Looks great! Now, I have to get off of my fat @$$ and work on my tube.

Now, all that's left to do is to get everything all back together and bolted down, chassis & tuner ETC, and get all wires tied back where they were, get the set to where it's going to be finally kept, and do final fine adjustments when it's there.

latest video.

http://suzaku.live-evil.org/0811232252.mp4

pretty much done.

tuner and chassis back in

minor adjustments left when moved to final location, Height /lin
the color echo is still there, but not much I can do about it, I dont have the tools to do a bandpass alignment

http://suzaku.live-evil.org/0821232202.jpg

Maggie moved nest to the Hoffman Colorcaster television.

Will do final adjustments this weekend.

As I expected, rotating the set at a right angle to move it to it's final location made a slight change in the convergence alignment, not so much with purity however, spent over 2 hours going round and round with the convergence to get it close as I could, still not perfect, never is, problems as always on the right side, un-even lines that refuse to line up, I have NOT changed the diodes on the convergence PCB yet, that may be the reason, will most likely replace them with Mouser part 637-MUR160.

The slight color shadowing is still there, barely noticeable, but there, may look into that at a future date.
One thing that makes this set even MORE oddball is it does not have an AFT defeat switch as shown on the SAMS, but has a 2nd weird color switch, I wish it did have the AFT defeat switch, cause it's rather annoying.

The auto color switch is the AFT defeat switch.

Unfortunately, I don't have a B&K 415, or really exp with one. :(
I did play with a Heathkit IG-57A in HS, but it was built by an amateur and I'm sure it did not work correctly.
I could no doubt use one, cause I have sets that could benefit from alignments.
The Magnavox T933 for example, as mentioned the color shadow is most likely from a chroma bandpass problem, adjusting the 4.5 MHz trap has only a slight impact on it, what seems to have the biggest effect is to turn color to max, tune to max color w/o interference (oversaturation), and then pull back on color killer to minimize color with color cont at max, this does not get rid of the shadow completely, but greatly reduces it to where it is hardly noticeable.

This damn Maggotbox has a strange habit of refusing to turn on with any color lock once in a while, just rainbow screen, like the burst amp had failed or something. I don't like the tube they use, 6ke8 seems very unstable, then suddenly it starts working again, solid as a rock.

perhaps I should get MORE than just the 2 6ke8 tubes to try in it?

to see what makes it happy all the time?

Oh, these intermittent PITA issues... if this tube don't reached audiophile prices, is worth to try.

Looks like I'm not the only one who has been though the Maggie hell! :tears:

http://www.videokarma.org/showthread.php?t=269466

It's still tending to act up sometimes, turned it on last night, color came on OK, then after 10 min, barber pole effect was back for 30-90 sec, then it locked in again for the rest of the night.

On / off a few times, stayed locked.
Very annoying.

MORE NOS tubes on the way,
2x 6KE8s (burst amp / color killer ) , for a total of 4, 1 original, 3 nos, ( no sub listed for this )
Yet another 6GH8A , used in 2 areas ( 3.58 osc & cont / chroma bandpass & horz blanking) I already have many of these.

Other suspect, 6LM8 (video cathode follower-chroma sync amp / 1st video amp) 2 on hand, original , 1 NOS, it's stated that 6GH8A is a direct replacement, but not sure how this silly thing will react to it.
Will just have wait for the new tubes and play musical chairs with tubes to see if anything changes.

It works MOST of the time, but the 10-15% of time that it does NOT, is aggravating! :tears:

I'm not sure if this is of any help or not, but it sounds almost like your TV is electrically similar to my 1968 Sylvania Color TV that I'm currently restoring and my Sylvania TV is having similar issues to your TV (barber poleing, color not locking in correctly, etc) and the interesting thing is that my TV has no paper caps in it to speak of mainly mylar or ceramic disc caps, and a lot of carbon comp resistors, of which the 1/2W or smaller carbon comp resistors all measure within specs yet, but the 1W or higher carbon comp resistors all measured 10%+ high, and I've also replaced many tubes in my TV and still have issues similar to your TV, but I think the issue might be mainly related to the resistors that have drifted high, I'm not sure if that might be the case with your TV but it might be worth looking into.

:banana::D:thmbsp:

HA!
I caught it this time!
ran it for a few hours, the first hour no problem..
then it did it again. :tears:
shut out all lights took a look REAL close, V22 was out cold! (6KE8 burst amp / color killer ) , wiggle tube, lit up again, color came back! dirty socket? perhaps?

I did clean them, perhaps it's being stubborn!

:banana::D:thmbsp:

HA!
I caught it this time!
ran it for a few hours, the first hour no problem..
then it did it again. :tears:
shut out all lights took a look REAL close, V22 was out cold! (6KE8 burst amp / color killer ) , wiggle tube, lit up again, color came back! dirty socket? perhaps?

I did clean them, perhaps it's being stubborn!

Or the PCB ground lugs to the main chassis.

Zeno:smoke:

Or the PCB ground lugs to the main chassis.

Zeno:smoke:

Those were touched up, and looking at the diagrams, the ground traces to that area would have impacted substantially more than just the loss of color sync if that area lost it's ground, so far it seems that it is just V22 losing heater power due to a weak / socket connection, or a missed broken solder joint under it.
But , at least now I know the source of the annoyance!:D

Those were touched up, and looking at the diagrams, the ground traces to that area would have impacted substantially more than just the loss of color sync if that area lost it's ground, so far it seems that it is just V22 losing heater power due to a weak / socket connection, or a missed broken solder joint under it.
But , at least now I know the source of the annoyance!:D

That's good to hear, now I know what to look out for on my Sylvania TV that I'm restoring when I start losing color and what not, because like I said my TV is more or less a copy of your TV (an RCA Clone perhaps?) more or less the same tube complement.

It's not exactly an RCA clone, I DO see some RCA in it, but also some Motorola and perhaps even some Zenith, it's like they took some from all, and headed out in their own direction.

It's not exactly an RCA clone, I DO see some RCA in it, but also some Motorola and perhaps even some Zenith, it's like they took some from all, and headed out in their own direction.

Interesting, I'm kind of surprised that's the case, so I wonder if Sylvania did the same thing then because when I was following your thread I saw a lot of similarities between your TV and my Sylvania I've been working on, although I guess that wouldn't be too surprising if that was the case considering Magnavox and Sylvania both ended up getting eaten up by North American Philips in the 1980s... :scratch2:

This set is sort of like the the RCA-CTC 20 with the cathode follower after the video det, but uses a demod I have not seen in RCA before, but does seem to have the RCA color ref osc and horz circuit.

This set is sort of like the the RCA-CTC 20 with the cathode follower after the video det, but uses a demod I have not seen in RCA before, but does seem to have the RCA color ref osc and horz circuit.

Interesting. Can you post a schematic of the demods?

Interesting. Can you post a schematic of the demods?

I will later tonight when I'm home, at work, I'm limited with what i can do. :tears:

I will later tonight when I'm home, at work, I'm limited with what i can do. :tears:

Darned work! Always getting in the way! :D

Here it is! :P

http://suzaku.live-evil.org/maggie-video.jpg
http://suzaku.live-evil.org/maggie-color.jpg

The video section really does remind me of the CTC-20 :O

The demods and color difference amps are very much like RCA too, except for using the 6MK8 dual pentode instead of separate X and Z demod sections.

Would have to do a detailed analysis to see if they had different color difference gains and angles than RCA.

Well people were blasting the "crappy Chroma demoduator" used in the "magget box" When I posted about this on FB vintage TV forum, with stuff like ," I hated the Magnavox tube sets! Chroma demoduator was crap, could not get good flesh tones."

I cant really say, but i DO like the CTC-16XL better, and this is the only and first set i have seen using a 6MK8. :scratch2:

Well people were blasting the "crappy Chroma demoduator" used in the "magget box" When I posted about this on FB vintage TV forum, with stuff like ," I hated the Magnavox tube sets! Chroma demoduator was crap, could not get good flesh tones."

I cant really say, but i DO like the CTC-16XL better, and this is the only and first set i have seen using a 6MK8. :scratch2:

Yes they had that reputation. There is a switch we called the brownuator SW.
If on it gives gives a brown cast to the color.You have to also watch the
plate resistors to the demods. Motorolas & Sylvanias too ! Bottom line
is turn off the auto color switches, AFT is the only one to use IMHO.

To be fair Zenith did something similar. Early " Custom" series sets
( 9-181 main board ) that replaced the S3 ( 9-160) had a puky orange pix.
Then better sets came out & had a great pix. A few minutes in the
manuals gave the reason. Better sets had auto color, cheap sets did not !
Turning off the auto color gave the good pix, turning it on gave the orange
pix. So from that point on we modified every one without auto color we sold
& the pix was as good as any.
Told the Boston service rep about it & he told me "this conversation never
happened" and DONT tell Chicago !

enuf fer now
Zeno:smoke:
LFOD !

... Better sets had auto color, cheap sets did not !...
Zeno:smoke:
LFOD !

Do you mean the cheap sets had no switch but had autocolor permanently on?

Do you mean the cheap sets had no switch but had autocolor permanently on?

Exactly ! Cheap sets it was always on, better sets had a SW to turn it off.
IIRC it used a Hitachi IC & the same era Hitachis had a displeasing color palette
also. IIRC the original IC was a 221-### later was a 221-###-01
and the color problem went away.

Zeno

So far, knock on semi-fake wood, the Maggie has been behaving after the tube wiggle, I try it about twice a week, and so far, the loss of color sync has not come back, weird!

Dare I put the back cove on it and tempt fate! :O

I have finally found the source of the loss of picture (brightness ) that happens once in a very great while with this set, all this time I have been keeping the back off in hopes of nailing it down, this week I did, the brightness pot, R2 is on the front, like the color and and volume, but unlike being hard wired in the RCA and GE sets that amused bandersen a bit, :) this one can be unplugged, and THAT is the source of the problem, weak connection in PL3, the connector to the brightness pot on the front, I DID clean them, but this one is still giving me trouble, when I lose picture, I grab the wire, move it a bit, and it comes back.

I have finally found the source of the loss of picture (brightness ) that happens once in a very great while with this set, all this time I have been keeping the back off in hopes of nailing it down, this week I did, the brightness pot, R2 is on the front, like the color and and volume, but unlike being hard wired in the RCA and GE sets that amused bandersen a bit, :) this one can be unplugged, and THAT is the source of the problem, weak connection in PL3, the connector to the brightness pot on the front, I DID clean them, but this one is still giving me trouble, when I lose picture, I grab the wire, move it a bit, and it comes back.

Its not uncommon for the pins in the plug that have wires in them to develop bad solder joints...It's especially common in CRT heater pins to the point that they made a special repair tool to crimp the pin onto the wire...If there isn't a service reason to have it unplug you could hard wire it...last year I had to hard wire one terminal of the chromatic switch socket because it was less of a PITA than replacing the whole thing (not like I had a replacement either).

Just replaced the 150K ohm in my Maggie T-933. It went up to almost 300K ohm.
Back on and bright picture and terrible retrace. Loose 6LM8. Pushed it back in and good picture and vertical again.
Like you said, "Maggie Hell".
When I get a chance I'm going to check the 100K resistors in the back control board. Just don't trust them..

Just replaced the 150K ohm in my Maggie T-933. It went up to almost 300K ohm.
Back on and bright picture and terrible retrace. Loose 6LM8. Pushed it back in and good picture and vertical again.
Like you said, "Maggie Hell".
When I get a chance I'm going to check the 100K resistors in the back control board. Just don't trust them..

R101? Yeah, I replaced that w/o question cause I knew it would be bad, along with R85 & R108, a spot check of other resistors in the set found that others were still good.