I have a small tube that goes to a tuner but the number I can't find any info about it, 210302a, the 210 is above the 302a That's the way it's on the tube maybe someone has a book to figure out a real number like all others have. I'm trying to see if this set is worth doing anything with. So far I get a line across the screen looks like no verticle drive at all. Checked all the tubes . Would there be anything simple to check why the verticle is dead. I don't have a schematic yet until I know I will do something with it.

If the set it is in has Sam's coverage between 1950 and 1967 there is a 98% chance the tube chart is sitting 10' behind me and I could post a picture of the tube chart... I could probably post a pic of the vertical section too...you gotta post the make, model/chassis or preferably the Sam's number for me to look it up.

Well this set is a cbs Columbia and the only schematic is on eBay but until I can get a full screen I don't want to get it yet. ETF don't have the SAMs . The chassis is 22c38

I have almost every Sam's between 101 and 860 and a several drawers worth on either side...I probably could pull the folder from my files and post pictures of needed sections for you here free of charge...

That would be great, thanks

That would be great, thanks

It is listed in Sam's 214 and 255 here's the tube chart and vertical stage of both Sam's.

Is it possible to use a ceramic cap in the verticle to see if the caps in verticle are bad which I'm sure they are since they are 65 years old, I just want to see if I can get a full screen and how bright the crt is, just temporary.

Seems easy enough to just replace the electrolytics there and then troubleshoot if necessary. Really a basic vertical circuit.

Seems easy enough to just replace the electrolytics there and then troubleshoot if necessary. Really a basic vertical circuit.

Electrolytics were changed but not the paper caps. Thinking of trying ceramic caps to see if this is the problem in the verticle only in place of a paper cap. Because if the verticle output trans is bad then I'm done with this set, it would not be worth it.

You could sub in ceramic as a will it sweep test (results may not be as linear or on frequency as desired).
Personally I'd just ohm out the transformers and if it is within tolerance recap the vertical properly.

You could also connect the output grid to the heater line via a cap to force the output to sweep some.

Well I could check the ohms but I'm really going need the schematic because I can't make out the numbers for the transformers its Alittle fuzzy.

Well on T4 I get nothing from both primary and secondary which I feel is odd because when a transformer goes usually there is at least one half would have some sort of reading, I get zero on both. So I guess this is the end of the road for this set. Ok, maybe I measured it wrong, the SAMs shows a red but I have no red on T4 I have green and blue on one side and white and yellow on the other side so I checked for ohms on the green and blue and its zero the same for the other 2 but if I cross over from one side to the other I get a reading, the green and the yellow or white its reads but I'm not sure if this is correct like other transformers. Maybe I got ohms crossing over because maybe there is a center tap . I need some light on this one befor I do infact give it up .

Ok with the colors I have on T4 I measured 1.544k across the white and blue wires and 6.5 ohms across green and yellow. So is this how these transformers are checked using the wires in the corners rather the both wires on one side .

Sam's 255-3 claims vertical output trans has a red & blue primary with 1.6k ohms and a green & yellow secondary with 5.5 ohms that seems to jibe with your measurements/it being a good transformer...colors can fade and a transformer maker can place the lugs or wires anywhere on the transformer they please...you'd have to track down the design engineer that made this and ask them why it is laid out this way.

Theres also a vertical oscillator transformer in this set the grid winding of that is Yel Grn 920 ohms and the plate winding is Red Blue 170 ohms.

Would that oscillator trans be the small one, T2 if that's the case the one I have here has the colors red and green on one side and the yellow and blue on the other side so this seems like a really odd way to wire a transformer it looks like maybe one wire from one side and one from the other makes up primary and the other 2 make the secondary.

Yes.

Ok well here's the numbers for the verticle oscillator transformer, your number was 920 and my number was 1014k and the other, yours 170 and mine .184k those numbers seem ok compaired to yours. Back to the drawing board.

Tom is it possible for you to tell me what the brightness pot is listed as ,what ohms because someone had changed the pot and the brightness will not turn the screen down and wilth a bright line across it will burn in if I have it on checking voltages.

Brightness control is 100K. Ends are connected directly to 120V B+ and Ground, wiper connects to cathode via 270K resistor. G1 connects to ground via 1M. G2 connects to boost. Gun voltages should be 45, 0 and 440.

Brightness control is 100K. Ends are connected directly to 120V B+ and Ground, wiper connects to cathode via 270K resistor. G1 connects to ground via 1M. G2 connects to boost. Gun voltages should be 45, 0 and 440.

Thanks for this info, it will help.

Well I compaired the voltages, yellow 82 v bright down screen still lit, green 75 v red 472v , orange 285v I assume focus , black and brown heater. No 45v or 0 . The bright pot measures 135k but it's still lit no matter which way it's turned and the 270k resistor is good . I'm wondering if whatever is going on with the brightness has anything to do with verticle. :scratch2: the 120v on the bright pot is there and the other end has a wire from there to the verticle hold pot which is tied to ground.

G1 is supposed to be 0V. It should have a 1M resistor connecting it to ground and it also has a cap connecting it to something. It sounds like G1 has become positive with respect to cathode in your set....that will give you 150% brightness regardless of brightness control setting on cathode.

Check the 1M resistor on CRT grid G1 for open and the cap that goes to G1 should be changed or disconnected.

Well that was a good call I have never came across that in the past I haven't worked on these sets as much as you have. The 1 meg tests at 1.3 meg and I clipped the cap and now the brightness works it has one of those bumblebee caps I don't know the value because it has color bands. So I guess I'm on to hopefully find why this verticle is not oscillating. Is the g1 cap even needed .Thanks tom

Glad to help.
Regarding bumble bee caps. Can you read resistor color code? And are you familiar with modern capacitor rating nomenclature that uses 2 digits and a multiplier to express capacitance in picofarads (is 102 is .001uf(1000pf), 153 is .015uf, 224 is .22uf)?....a bumbel bee is the modern numbering system encoded using resistor color code...the first 3 bands are capacitance there is usually a 4th grouped with the capacitance bands that I believe is tolerance (I typically ignore it) then there's 1-2 more bands that are further away representing the voltage in hundreds. A single red band is 200V a pair brown and blue is 1600V.

Is this bumblebee cap even required at all ?

Is this bumblebee cap even required at all ?

I'll have to look at the schematic when I go back to the basement later...I didn't check what it went to only that it could cause CRT bias issues that you were experiencing. I think video was cathode driven so the grid cap could be something like a retrace blanking circuit... I'll get back to you.

I'll have to look at the schematic when I go back to the basement later...I didn't check what it went to only that it could cause CRT bias issues that you were experiencing. I think video was cathode driven so the grid cap could be something like a retrace blanking circuit... I'll get back to you.

Ok ,thanks

I'm coming up with 2 different numbers for this cap. .047 and 47.
Yellow
Violet
Orange
Grey And blue by its self.

Yel violet orange is 473 which is .047, and Sam's says it is a .047 600V. It couples the plate of the video output to the CRT grid so completely necessary if you want video on screen.

Last night I had the things backwards going from memory. The CRT gets its video at it's grid and there's a vertical retrace blanking circuit feeding the CRT cathode off the yoke winding of the vertical...here's some pics.

Ok so I don't know if I'm correct in thinking that the verticle circuit starts at the oscillator then to the output then to the yoke. So the tube oscillates the oscillator transformer then that oscillates the output transformer. I'm trying to get a better understanding of how this seemingly simple circuit works. There is supposed to be 90 volts at pin 6 and there is not and -26 at pin 7 and 22v at pin 3 is present. If the verticle is running then the voltages should be there . At R77 there is 300 v from the height pot up should show some voltage but nothing near 90 v. Even the worst caps I figured there would be something even a 1 inch high picture but there is not just a razor lines across. The horizontal I would have thought would have been the headache.

I'd change caps C2 77, 78, and C80. Especially C2. Check R6, 76 and R77 too.
Paper caps short or develop excessive DC leakage current and can absolutely kill vertical oscillation and coupling to the output...you already saw what the CRT grid coupling cap leaking did to mess up brightness bias on the CRT...If the osc or output gets mis biased from cap failure leakage current the osc can stop dead or the output can have it's signal cut off.

Any section that has original caps you should expect to find dead and be surprised if it still works.

Ok I'm going to recap the whole set and hope for the best at this point . there are to many old caps to dance around. I'll post the outcome when it happens. Thanks tom for the tech info.

Does anyone know of another company like moyers that sells capacitors, moyers may not be open this coming week and I need capacitors. Maybe a name and phone number someone good that someone here had used befor. Thanks

Sal's Capacitors. Great to deal with and fast shipping. http://www.tuberadios.com/capacitors/ Contact info at bottom of page.

Does anyone know how to figure out the date code of a ge crt . The sticker shows code 6113 then under 188 is 50 and another number. A 103227

I vote for the 13th week of 1961 188 is the EIA code for GE. I think the A103227 is the serial number.

I've done good with mouser and digikeys websites for caps, resistors, diodes, terminal strips, etc.

Gotta, tick the filter by in stock box, and play with some of the filters to find what you need, but the price is usually better than more specialized vendors.

On a 21fjp22 crt , I'm trying to figure out what year this tube was rebuilt. It shows the word code and under that is the number one next to that is 82 then next to that is 9 . Would that be January 9 1982 ?

Ok so it's all recapped and still no verticle, I checked resistors around the vert oscillator tube and a lot of other places for the verticle and they are within range and also double checked the hold , height, linerety, pots all are good. I find that the vert oscillator tube is not oscillating because when I probe number one of that tube with my meter on ohms the screen wants to open so I'm at a loss as to why I can't get this to oscillate. I don't have a voltage chart for this set to check voltages.

Many years ago I ran into an RCA TV that had a vert osc that wouldn't run. The vert hold control read fine out of circuit, but I missed the part where it had about 100K ohm leakage through the case of the control to ground. When I lifted the vertical hold control off the chassis and let it float in the air, the vertical came back.

Long shot to be sure; in 50 years in consumer electronics I only saw this once.

John

Ok well now it's confusing, I got the SAMs for this set and it shows the sync phase inv tube to be a 6u8 but the tube lineup on the paper that came with the set shows a 12bh7 so weather this has anything to do with the verticle not working I don't know. If I try the 6u8 it may burn out but at the same time I don't want to burn up anything else by trying this tube.

There were 2 different Sam's for the model number you gave (I listed them I the initial post I made with schematic pictures) and the different Sam's had different tube compliments.

I should pull the two Sam's out later and see if either shows that tube...

Just for the heck of it, can 3 non polarized 100 volt capacitors be put in the series config to make a non polar 300 volt cap.

Just for the heck of it, can 3 non polarized 100 volt capacitors be put in the series config to make a non polar 300 volt cap.

Yes, not forgetting that they still follow the same rule of adding voltage but losing value in series. If the running voltage of the circuit is close to the total voltage of the caps, you might want to add some high value resistors across the caps to equalize the voltage across them so one cap doesn't approach the voltage limit.

John

Ok well I'll just put 2- 200volt 47uf caps together neg to neg and use the positives for the connections to make a 400 volt 24 uf non polar cap.

This tv is making me nuts it's all recapped and yet I cannot find anything wrong, resistors are not perfect but are still in the area verticle output and oscillator transformers check good ohms. The oscillator pins 6 and 7 have no activity at all . Pin 6 has 7 volts which should be 90 volts and pin 7 has negative .770 volts which should be negative 26 volts pin 2 of the same tube output side has 25 volts which is ok having 21 volts . So it seems there is a clear problem with the oscillator section and I concentrated on that area resistors and find nothing. Where there supposed to be the high voltages there is. I subbed the hold pot, height, and linearity pots still nothing just a horizontal line. I'm sure the voltages are simply not there because the tube is not conducting at least I think that's the voltages that are in the SAMs as a working set. The SAMs I have is a speck different but everything I checked already matches the SAMs I have if a resistor shows otherwise I check it anyway. I don't know if the yoke is needed for the oscillator to run but I just as well look into the yoke although nothing is burned visually.

With the yoke and CRT connected try connecting the osc grid to the heater line through a .1 if cap and if that doesn't give deflection then try connecting the output grid to heater voltage.

Transformers can have shorted turns...When that happens resistance can still be exactly normal but the transformer won't oscillate or pass signal normally.

Ok pin 2 with the .1 cap to heater the screen opens about 2 inches pin 7 it opens less then an inch. So there was Alittle deflection. So what might that mean, a bad oscillator transformer ?

If there is 2 different SAMs for this set then maybe the ohms would be different I really don't know because I have the SAMs that you posted in an earlier post and the part number for the oscillator trans I have here is A10106-1 but the SAMs shows PB10106-1 close but I don't know if I could use that one with the PB instead of the A if this trans is found to be bad.

Ok so I located a verticle oscillator transformer and hopefully this will cure the problem since spending days checking resistor , voltage sources, is making me nuts without finding anything. I have good sound and it has a picture that I can see changing in the horizontal line so at this point it's verticle or nothing. :scratch2::smoke:

Ok so by adding a .1 cap to the heater source to pin 2 grid of the verticle oscillator gives me Alittle verticle deflection, what does this mean, a bad oscillator transformer or a missing voltage source because I am out of ideas on how to get the verticle running. I do have the oscillator trans coming but I'm still looking around for other possible causes in case I put the trans in and that don't work, so I'm trying to be Alittle ahead of it. Any little help would be appreciated.

Ok well another dead end got a nos verticle oscillator transformer and of course still no verticle. I have went over a lot and I do know I'm missing something here and it should be obvious but I'm not finding what's going on here. So now I'll check voltages on neighboring tubes tied to verticle.

Hi Timmy,
Do you have an oscilloscope ? If you do check for the waveform at the grid of the vertical output portion of the 12bh7. If you do then your blocking transformer should be O.K. If there is a correct waveform at the grid then check for a wave form at the plate of the 12bh7 vertical output. If you get a wave form , then disconnect one of the leads from the vertical deflection coil. then test for a waveform on the secondary of the vertical output transformer. If you do get a waveform then you may have a problem with the yoke.
Ed

Hi Timmy,
Do you have an oscilloscope ? If you do check for the waveform at the grid of the vertical output portion of the 12bh7. If you do then your blocking transformer should be O.K. If there is a correct waveform at the grid then check for a wave form at the plate of the 12bh7 vertical output. If you get a wave form , then disconnect one of the leads from the vertical deflection coil. then test for a waveform on the secondary of the vertical output transformer. If you do get a waveform then you may have a problem with the yoke.
Ed
No I don't have a scope, I'm flying solo here, lol.

Hey tom, could you please tell me what the SAMs set and folder number is of the schematic with the 12bh7 tube, v8 , if you have it , the SAMs I have is with the 6u8 , v8 , there are obvious differences and I'm not getting anywhere without the right SAMs. Maybe I can find it with the right number. Thanks. Tim

Hey tom, could you please tell me what the SAMs set and folder number is of the schematic with the 12bh7 tube, v8 , if you have it , the SAMs I have is with the 6u8 , v8 , there are obvious differences and I'm not getting anywhere without the right SAMs. Maybe I can find it with the right number. Thanks. Tim
I did give the set number that contains it before...See link for full number.
https://www.samswebsite.com/en/photofact/search?t=model&o=0&k=22c38+&submit=Search&s=Search


The Sam's sites search function is something every collector that uses Sam's should be familiar with...I use it instead of my paper copy of the index because it is faster. You now have been taught how to fish (for Sam's numbers).

...... You now have been taught how to fish .......

Just like the old saying goes "Give a man a fish and he'll eat for a day , , , ,

, , , teach a man to fish and , ,

:mad: and , AND , AND he'll sit on his ass all day on the boat drinking beer with his buddies and not get anything done around the house :mad:

Oh , wait , that was the X who used to say that , nevermind ..... :D

Just like the old saying goes "Give a man a fish and he'll eat for a day , , , ,

, , , teach a man to fish and , ,

:mad: and , AND , AND he'll sit on his ass all day on the boat drinking beer with his buddies and not get anything done around the house :mad:

Oh , wait , that was the X who used to say that , nevermind ..... :D
:lmao: LMAO...the bad X's version of a proverb about knowledge and self sufficiency. :D

Ahh , ok , I don't fish anyway , lol

Oh and tom, there seems to be 3 versions there are 2 214 that is listed they have different item numbers so I'm not sure but I guess start with the one that hopefully has the right tube.

Oh and tom, there seems to be 3 versions there are 2 214 that is listed they have different item numbers so I'm not sure but I guess start with the one that hopefully has the right tube.

There's only one version of Sam's folder 214-2 in my paper library....The monkey/intern/temp they had scanning the paper to PDF probably goofed and scanned it twice (especially given the item numbers for the pdf files are sequential).

Personally I'd check eBay for a cheaper original paper copy of Sam's 214-2 before I'd buy a mediocre scan or photo copy from Sam's website....the only reason I visit the Sam's site most times is to use the search function to tell me exactly where in my file cabinets I can find the schematic...

Yes I'm looking into eBay but your version you posted on page one shows the right tube but my set has a non polar cap that your 214 don't show so there may have been changes along the way. The problem I may have is there is no grid voltage to set the oscillator running but I have to wait to see if I get the 214 SAMs.

On a 5u4 rectifier tube the plate terminals are 4-6 this set had a 5u4 in it but numbers 3-5 have the ac so a 5u4 may only work on one side so is there another rectifier tube that uses 3-5 ? It may be the 5x4 since I don't have the right SAMs. Ok here's a weird update the transformer has output on 3-5 but the filiment source is 2-8 but the 5x4 the filiment is 7-8 so both these tubes won't work unless a jumper is put in place, so I don't know what's going on here I don't think there is another tube that would have 3-5 for the plate and 2-8 for the filiment.

Are you sure you're not reading the tube the wrong way around ? 4-6 would look like 3-5 if you count around backwards.

Are you sure you're not reading the tube the wrong way around ? 4-6 would look like 3-5 if you count around backwards.
Well yes you are correct I had the chassis on its side and I did count the pins backwards so that's good , but still cannot get the verticle running .

Hey tom, how much do you want for a copy or some sort of scan of the SAMs you have that has the 12bh7 tube not the 6u8.

Presently due to covid19 I'm not allowed to go to any public location with a good copier (my folks won't let me back in the house if I do that or anything similar). If I could do that like normal I'd change you the cost of the copy and postage.

The only scanner in the house is a 8x11 unit my folks own (and I have never used)...if you don't mind 17x11 sheets being fragmented into multiple 8x11 scans I can try that later...If I can scan it and find a way to get the files to you then you can have the scans gratis.

If my employer had only made work from home voluntary instead of mandatory like they did I'd try to scan it there...

Presently due to covid19 I'm not allowed to go to any public location with a good copier (my folks won't let me back in the house if I do that or anything similar). If I could do that like normal I'd change you the cost of the copy and postage.

The only scanner in the house is a 8x11 unit my folks own (and I have never used)...if you don't mind 17x11 sheets being fragmented into multiple 8x11 scans I can try that later...If I can scan it and find a way to get the files to you then you can have the scans gratis.

If my employer had only made work from home voluntary instead of mandatory like they did I'd try to scan it there... oh hey tom anything at this point would be a huge help this set is driving me absolutely crazy, you can even email me with what ever you can do and again if there is a charge let me know. If you need the email just send me a pm and I'll give it to you. Thanks a lot. Tim. Ps I don't need the whole thing mostly just the main page and the cap or parts list that should be it.

Well my folks informed me their scanner does not work. I downloaded a scanner app for my smartphone and while it is not as good as using an actual hardware based scanner I think it is better than the pictures I have taken so far....my PM box is full so I can't send any. Click on my user name and select the 'send email to Electronic M' option and send me your email address and I'll email you back the PDF of the schematic and parts list.

Well my folks informed me their scanner does not work. I downloaded a scanner app for my smartphone and while it is not as good as using an actual hardware based scanner I think it is better than the pictures I have taken so far....my PM box is full so I can't send any. Click on my user name and select the 'send email to Electronic M' option and send me your email address and I'll email you back the PDF of the schematic and parts list.

Ok tom I sent the email address. Thanks again for your help.

No problem. You should have the file in your email.

No problem. You should have the file in your email.

Hey tom I got it thanks again, but amazingly that SAMs is different Like the one I have but your SAMs has the right tube and comparing to the chassis I have here is clearly different. Different values on resistors as well as voltage differences even the way things are wired. There is a cap or 2 in this set that is not on either SAMs .I had recapped this set one cap at a time so I know I didn't put a cap in the wrong place. So I guess there is more then 2 SAMs for this set so at this point I'm not sure where to go from here. There are several 470k resistors that are in the verticle measuring .540m and .539m so I don't think that is so bad but if there were changes maybe these resistors in a given circuit cannot tolerate a rise in value. These resistors in both SAMs show 100k , clearly different. And the chassis didn't look like it was ever touched. :scratch2::smoke:

Is there any chassis that had 2 or more SAMs for the same chassis ? I had gone over 2 SAMs for the same chassis and they are wired differently and it's frustrating to find the right one since it looks like there maybe 3 or 4 of the same folder number and one different. No wonder cbs Columbia never made it up there like RCA and others. This set has all the power supply caps ground to the chassis so how is it possible to get over 300 volts from a cap that is grounded to the chassis and the positive to the verticle height pot to the plate of the oscillator with only 15 volts, pot turned up, it's not possible. There is 300 volts befor a 470k resistor but after there is 15 volts and the resistor is good. These original caps were one cap with 3 caps inside or 4 inside , the multi caps, so I don't know if these caps had some sort of internal connection, I don't know how that could have been done. The oscillator plate needs over 100volts.

Well I finally got verticle running but I do have a horizontal line that is bigger now but I now have lines from top to bottom like retrace lines and still no pic so without the proper SAMs I'm taking a guess on certain things. Video output and horiz and vert sync next.

Any ideas where to go from here, I hope it's not the yoke, I'm sure you guys have seen a lot of this but I haven't, I'm lost, lol. I am wondering if the flyback may be responsible here since I checked the ohms on the flyback and compaired it with a flyback I got from early television museum and pins 2 and 8 on the new one reads like 3.2 ohms but on the fly in the set don't read anything. I don't know if the flyback would do this.

It looks like you have dim non-linear deflection in the upper half and possibly more above. Do you have a scope?...If so I'd check the vertical waveforms against Sam's.

Well I don't have a scope so it took longer to track down the problem here's the result. This IPad does this all the time upside down photos. :no:

Looks like you got it working? What was the problem?

Looks like you got it working? What was the problem? a few stubborn 66 year old mica caps which some still say, oh they don't go bad, oh but they do. :D

Well I don't have a scope so it took longer to track down the problem here's the result. This IPad does this all the time upside down photos. :no:

My android does the same. Here's a free on-line tool that will resize the image, crop the image, and rotate the image the way you want:

https://resizeimage.net/

Easy to use and doesn't mess with the resolution as far as I can tell. I used to use MS Paint and other photo apps on my computer, but this works as well and is far simpler.

Here is a pic that I converted using that link. This image was both cropped to show mostly screen and rotated 90 degrees:

https://i.imgur.com/hDwmMKm.jpg?1

John

EDIT: here's your pic cropped and rotated using that on-line tool:

https://i.imgur.com/D5p80q1.jpg

My android does the same. Here's a free on-line tool that will resize the image, crop the image, and rotate the image the way you want:

https://resizeimage.net/

Easy to use and doesn't mess with the resolution as far as I can tell. I used to use MS Paint and other photo apps on my computer, but this works as well and is far simpler.

Here is a pic that I converted using that link. This image was both cropped to show mostly screen and rotated 90 degrees:

https://i.imgur.com/hDwmMKm.jpg?1

John

EDIT: here's your pic cropped and rotated using that on-line tool:

https://i.imgur.com/D5p80q1.jpg


Interesting choice for a test subject to display. :D

Right side up certainly is much better, lol

My guess is since plenty of dummies think Corona beer is somehow associated with Corona virus they aren't getting any business and are advertising hard to try to stay alive...
Back during WWII Japs potatoe chips changed their name to Jays (and stuck with it) to deal with the business hit they took when Pearl Harbor made much of the country hate the Japanese... Corona may have to do something similar to disassociate with the virus in people's minds...

My guess is since plenty of dummies think Corona beer is somehow associated with Corona virus they aren't getting any business and are advertising hard to try to stay alive...
Back during WWII Japs potatoe chips changed their name to Jays (and stuck with it) to deal with the business hit they took when Pearl Harbor made much of the country hate the Japanese... Corona may have to do something similar to disassociate with the virus in people's minds...


so, grab up all the Corona beer you can now! It will be a collector's item soon!

I'll stick with collecting tvs, I don't drink. So I'm back to square one now , the horizontal took a dump it became very unstable and with the afc used as the horiz hold its got to be right, there is no hold in this set. The picture went black then came back so it's off to the Micas in the horizontal now. :sigh:

I'll stick with collecting tvs, I don't drink. So I'm back to square one now , the horizontal took a dump it became very unstable and with the afc used as the horiz hold its got to be right, there is no hold in this set. The picture went black then came back so it's off to the Micas in the horizontal now. :sigh:

As annoying as it is for a set to have a failure post restoration it is always better when it happens on the bench where you are set up to fix it instead of reassembled in your living room or more frustratingly RIGHT as you are tightning the screws on the back like my CTC4 did last week. http://videokarma.org/showthread.php?t=252909&page=5

As annoying as it is for a set to have a failure post restoration it is always better when it happens on the bench where you are set up to fix it instead of reassembled in your living room or more frustratingly RIGHT as you are tightning the screws on the back like my CTC4 did last week. http://videokarma.org/showthread.php?t=252909&page=5

OH yes I agree I am glad it happened when it did although it has happened to me befor. But I knew something was not right when the afc couldn't stop the pic from going crazy and the geometry of the pic kept changing, so it's good because I'm kind of certain it's Micas , there are 4 responsible for horizontal. Even the rings couldn't set the centering correctly.

so, grab up all the Corona beer you can now! It will be a collector's item soon!

I'll stick with collecting tvs, I don't drink....


:thmbsp: Timmy your not supposed to drink them , your supposed to collect them , so that when they become a collector's item you can sell em and buy a CT-100 with the pile of dough they'll haul in .

Ok then :D

So with doorknob capacitors, how can you tell if they are going bad , like symptoms, since you really can't tell by just checking them without hv running threw them. Do they become intermittently problematic ?

So with doorknob capacitors, how can you tell if they are going bad , like symptoms, since you really can't tell by just checking them without hv running threw them. Do they become intermittently problematic ?

I've seen doorknobs dead short on a dime and I've seen them go flakey where the HV will fluctuate between almost normal and dead (horizontal will act flakey due to the extreme load fluctuations)....

If there is dag on your glass CRT and it is grounded then you can remove the doorknob and power the TV to test it (the doorknob is likely redundant). If the set opperation improves substantially the doorknob was bad.
If you disconnect it put a glass or ceramic ( a jar or coffee mug often works) insulator in place to prevent the disconnected end from arcing.

In the early 50s many sets that didn't need a doorknob would have one.... many TV makers would have one chassis drive a wide variety of CRT sizes and if one of those CRTs was metal then every chassis made would have a doorknob.

So more then likely this set may be able to function without the doorknob ? The crt does have factory dag and has a ground tab and the crt is aluminized with the ion trap really bright. Well I changed the Micas which were way off in value and the horiz is cured but had a line in the middle top to bottom which was with the new Micas it changed the horiz frequency and the hv was to high, adjusted , done. Then again the doorknob would have to be there because I think it provides focus voltage.

Ok now more trouble I have 4 mica caps 3 are rated 2500 volts and one rated 1500 volts, where the hell am I going to find those caps. I think the only ones made are 300 and 500 volts. :sigh:

Ok now more trouble I have 4 mica caps 3 are rated 2500 volts and one rated 1500 volts, where the hell am I going to find those caps. I think the only ones made are 300 and 500 volts. :sigh:

what uf value?

598-CDV30FK302J03 $20 each? :o

2 - 10 pf and 1- 22pf and 1-5 pf the 22pf is 1500 volts the others are 2500 volts.

that's really high , :o you may have to go film, for lack of being able to find anything else :/

that's really high , :o you may have to go film, for lack of being able to find anything else :/

Those cap values are pF so really low...

If micas are not available C0G ceramic caps would be a viable alternative.

Those cap values are pF so really low...

If micas are not available C0G ceramic caps would be a viable alternative .

cog ?

C zero G it is a temperature coeficent rating for ceramic caps...that specific rating means they don't drift with temperature changes....old ceramics were hard to make temperature stable so micas were used instead.

cog ?

https://www.allaboutcircuits.com/technical-articles/x7r-x5r-c0g...-a-concise-guide-to-ceramic-capacitor-types/

Oh ok I should have know, npo marked on some ceramics the temperature stability. Ok I just have to find them now. I can get my hands on 12pf to take the place of the 10pf caps would this make much difference ?

Oh ok I should have know, npo marked on some ceramics the temperature stability. Ok I just have to find them now. I can get my hands on 12pf to take the place of the 10pf caps would this make much difference ?

Where in the circuit is the 10pF cap? This will determine if the value is critical.

It's in the horizontal but I don't think it's in the oscillator since I just changed 3 Micas in the horiz multi. The 2 10pf caps one comes off the horiz drive adjustment to the flyback along with a 5pf in series and the other 10 is across 2 680k resistors to one side of the vert output transformer. And ties to one part of the yoke.

Well, the schematic image that was posted is almost too fuzzy to read, but if I am reading it right, the 10 pf is the one on the right and the 5 pf is in series to the left and then goes to the horiz drive adjustment variable cap. I can't make out the range of the variable cap, but I suspect it's great enough to handle a change from 3.33 pf to 3.53 pf, which is the series combo of 12 and 5 pf vs. 10 and 5 pf.

The 10 pf across two 680k resistors goes to a connection that goes off the page to the right, so not sure what it is doing or how critical. I guess you could try 12 pf, or you could put a 56 pf (or 68 pf) in series with 12 pf to bring the total closer to 10.

The variable cap is 25-280 pf the other 10 pf runs to both side of the verticle output transformer like a circle. With a tap coming from the flyback.

... the other 10 pf runs to both side of the verticle output transformer like a circle. With a tap coming from the flyback.

I'm not following that. I see the right side connected to the horizontal yoke winding and flyback, but where does the left side circle back to the vertical? Does the left side go off to a video or AGC section? In that case, it is probably just a pulse shaper for input to the circuit it goes to and the the connection that goes back from there to the vertical may be carrying an unrelated pulse. (??)

I'm not following that. I see the right side connected to the horizontal yoke winding and flyback, but where does the left side circle back to the vertical? Does the left side go off to a video or AGC section? In that case, it is probably just a pulse shaper for input to the circuit it goes to and the the connection that goes back from there to the vertical may be carrying an unrelated pulse. (??)

Ok you should be able to see the rest of the circuit.

Here's the pic.

Here's the pic.

blury :o

Here's the pic.

It's the lines that go vertically off the top of your picture next to the CRT that I'm wondering about. Is that where the "circular connection" to the vertical output transformer occurs? What is up there?

It's the lines that go vertically off the top of your picture next to the CRT that I'm wondering about. Is that where the "circular connection" to the vertical output transformer occurs? What is up there? hopefully this shows more.

hopefully this shows more.

OK, so it's going to G2 on the CRT. Can't read the value of the cap attached to G2, but if it's much bigger than 10 pF, then the 10 pf and 680ks appear to be loading the horizontal yoke winding. You can go ahead and try 12 pf, and if it does something weird like change the width or retrace time slightly, you can add 82 pf in series to bring the total back close to 10 pF.

Ok the g2 cap to ground is a 22pf I guess that's the cap you are referring to. If the yoke is being loaded what am I going to see, is it the difference in the width or retrace lines.

Ok the g2 cap to ground is a 22pf I guess that's the cap you are referring to. If the yoke is being loaded what am I going to see, is it the difference in the width or retrace lines.

Well, I have reached the limit of my knowledge. The 10 pF going to a 22 pF looks like a pulse voltage divider, but I don't know why you would want a pulse on G2. My guess is that the value of the 10 pF is not super critical, so if you only have 12 pF, give it a try. Still surprised you can't find 10 pF caps.

Maybe someone else can figure out what's going on here.

Just dawned on me that it may be a negative pulse, providing horizontal retrace blanking...not sure.

What would be the closest match for a 4.7nf cap . Got a bumble bee cap with this low value but I don't see a 4.7nf on the list of caps from just radios that is available.

What would be the closest match for a 4.7nf cap . Got a bumble bee cap with this low value but I don't see a 4.7nf on the list of caps from just radios that is available.


https://www.mouser.com/ProductDetail/Panasonic/ECQ-E6472JF3?qs=sGAEpiMZZMv1cc3ydrPrF4aGm1X0erhBWPELGY iw8B8%3D


just 1 of many they have

you did not mention the voltage, i just picked 600 at random

Does anyone know if there is an allowance for a mica cap to drift, like no more then a certain amount above the face value of the mica ?

Anyone ever seen one of these and or what would be the benefit in using it ?

Anyone ever seen one of these and or what would be the benefit in using it ?

prob something like...
https://www.universal-radio.com/catalog/hamacc/2914.html

Yup it looks like the same thing only modern.

Unless you are or live close to ham radio operators that thing is probably most useful as a paper weight or dust collector...

This cbs Columbia has got to be the worst set I have ever worked on but then again it's 66 years old so it was expected. First the verticle, no sweep, then it looked good then the horizontal, no sweep, then after replacing Micas in the verticle and the horizontal I got both back but the picture was very unstable pulling to the left and right and the horizontal lines coming and going and the verticle rolling and unstable. Finally I realized the problem was in the IF so I spent about an hour and a half adjusting it out since I couldn't do a real alignment not having the proper gear it looks like I finally got it. You never know what anyone has done to an old TV set befor you get it or what screws or adjustments were touched. So now comes running it for a certain amount of time to make sure there are no more surprises that creep up. :scratch2:

Ok, finally got this cbs done.

Ok well this iPad did it again, upside down, sorry.