admiral 24c15 with 20b1 chassis attempt at restore
 

Recapped powersupply section separate chassis and thought Id see if it had life by variac. Absolutely nothing. My shaver cheater cord is making contact and power switch working. Thought Id check fuses and discovered holder for both fuses was/is/ in the process of failing. Hunting for screws/nuts to fix this then see if tubes light.
Fixed fuse block with screws and nuts. Now power supply tubes light up but tv chassis filaments seem to be not lighting. dont know yet if this is a series string tube chassis. power supply does have a 6k6 instead of a 6v6 tube in it. Not sure thats good for testing or not.

It is not series string. You need to make sure that connector from power supply to TV chassis is making good contact on all the pins. Put some pressure on it and wiggle a little while it's powered up and see if the TV tubes light up

I created a YouTube series on restoring this set you might find useful.
https://youtube.com/playlist?list=PL...eouW5jJSvC1YQM

ok y es had thought you made a video of this chassis. also found it on schematic. so yes not series string. coudnt find your video series on it so yes thanks for that.
Update: wiggled and reapplied radioshack tuner cleaner and lube with my finger to the main power supply connector pins and reinserted several times and got all tubes to light. Bonus is picture tube raster so its recapp time of the rest of it. Ratheon picture tube. ON back on back of hv cage in pencil crtube 2-9-52 so thats very cool. Maybe thats why inside of tube doesnt look very burnt at all near element like high mileage crt's do. Tested awesome on the cr70 sencore tester assuming the tester is accurate. going to have to watch the banderson 20b1 chassis series I found one of them but they didnt autoplay as Id hoped. Raster picture is at 90 volts

Fantastic!
By the way, after you upload an image you can wrap the resulting URL in '[img] your image URL [/img]' and it will display in the comment.

http://www.videokarma.org/attachment...9&d=1719061318

http://www.videokarma.org/attachment...0&d=1719077139

Ok I had forgotten that img thing posting pictures, since its been a super long time since I had even messed with radios/tvs.

https://www.youtube.com/shorts/xU_c2sI6upU
Also trying to figure out how to get raster more twards the bottom of tube currently. Picture looks like its maybe rolled over?
After 3 caps installed to replace multisection cap,(1st 3 caps in main chassis I had done!), I lost raster, had to figure out why! Translation: I had decided after the complete tube test and pin straighten(daughter helping so maybe too much extra tube wiggle widened socket pins) with dabs of deoxit on tube pins, I took the chassis over to friends house, did the 3 caps and bam no raster! discovered yet again tube filament problems. 6bg6 wasnt lighting. I even tested the 2 and 7 pins to discover no voltage. I dont know if I tested wrong pins or wasnt supposed to test for ac but no voltage. Decided to tighten tube socket pins because it just didnt feel right and bam tube lit after that. Tube gets same voltage as other tubes so its not like that tube had its own special voltage.

I really do need a readable schematic. I think I got mine off the etf but I cant seem to download new eyeballs to read it.
Wow! In beginners guide to tv restoration part 4, I noticed your ion trap, the screws are totally horizontal. Mine are not! Different picture tube maybe, Makes me wonder if My ion trap is way out of adjustment. For the pie dual 40 micro farad caps I used 47uf at 450 volts.

For your re cap do it one stage at a time. Recheck as you go every few caps.
Order is: power supply - HV & horz - vert - then the rest......
Many sets never work again after a re cap so go slow.

47 mfd is fine for 40's. Off the shelf caps come in 1, 2.2, 3.3, 4.7
10, 22, 33, 47 etc. SO use a little higher in mfd, voltage & heat.
Tolerance is high ( 20%) anyhows.

good luck
Zeno:smoke:
LFOD !

Ion trap magnet position is going to depend on the CRT electron gun structure and how the CRT is positioned on the chassis. It won't be the same from set to set.

I didnt recap by stage but I think I did by area of chassis. 3 to 4 caps at a time and test fire it. I dont have enough experience to recognize a stage just by looking at it from underneath just because Ive never tried to identify a stage but maybe I should try to figure out exact stage beginnings and endings with this tv. Raster is close to bottom of screen now. still not at bottom though maybe less than 2 inches. Trying to remember what adjusts total vertical position up and down or maybe there isnt an adjustment for that and something else is off. I didnt try to crank up voltage above 90 volts I forgot. picture faded dark when I went over 90

Hi,
I am entering your discussion late.
ACCORDING TO YOUR VIDEO YOU HAVE TO CHECK RESISTORS!:yes:
The fault in question could be a problem with caps, tubes and resistors!
Just when you pull the old caps, it is a chance to test resistors, with one end
in the air!
There are not so many in the vertical section.
From my experience I like to say, your issue is a combination of caps and resistor(s)!
They are aging fine...:thumbsdn:

Regards,
TV-collector:stupid:

Right now Im having problems with the 6bg6 tube. I thought the pins were loose because its not lighting again. Either the socket is really that bad or voltage isnt getting to the tube or the tube is some how being affected by something dont know yet

Is yours a TV only or combo unit? The combo unit cuts filament power to the 6BG6 when in radio or phono mode.

television only as far as I know. if theres a radio hook up to it I dont know. chassis says 20b1.. maybe me cleaning and tightening the tube socket is just coincidence that the tube lights sometimes. I did get to test the voltage at bottom of socket once and it was like 4.98 volts......thats low!
Just looked on front and I do not see any indication or printing of the word radio or phono on front of cabinet
https://www.youtube.com/shorts/15qjJ2yhfvk

Yep, TV only for sure. All the tube filaments are wired in parallel. What's your line voltage going into the set? Should be at least 117 VAC. These sets draw quite a bit of power. Could be your line is sagging.

Other tube filaments do not dim. Only the tubes 6bg6 and 1b3 get dim when screen goes away if i turn up voltage past 90. Screen faded once when i had it at 90 too.will check line voltage at tv chassis but dont think voltage is dropping

Must fix weird 6bg6 filament works/then doesnt work issue...I wonder if its arcing making filament do that

You are running the set on only 90 volts? Use 117.

Ok then run on 117 and test....i guesss alll caps are replaced except for the single wire can that just says a part number on it...no value on it..havnt looked it up on parts list yet.
I do still hear vertacle buzz when picture is faded out and or 6bg6 isnt lit. Can also vary the buzz with front control knob. Makes me also wonder if a resistor is getting hot and opening. Restors are next anyway.
Fascinating! I just figured the high voltage was going away when I cranked it to 117 volts. Its not. Screen lit about 100 volts measured and high voltage is about 7k. When I crank it to 117 volts the high voltage goes to 9k which is what schematic says. Weird its like somebody cranks down the brightness to zero with in 5 seconds after I crank up line voltage to 117.
I did manage to check the 6v6 audio output tube to see if somebody biased it differently because it had a 6k6 installed. Seems wired for 6v6 so I popped in a 6v6.

I decided to mess with ion trap magnet. and adjusted it for full brightness. Low and behold 117 volts and I got a screen! So, because I only know that the magnet redirects the electrons back to the screen, very fascinating that with the ion magnet off... screen is affected by line voltage level almost like line voltage affects when screen electrons hit screen.

Line voltage will affect the current flowing through the focus coil which interacts with the ion trap magnet. It's all connected.

Still trying to wrap my head around ion trap being off and raster showing up then fading out the second i turn up line voltage to 117 volts. Would have thought raster would still be visable just not as bright. So the second i turn up line voltage i guess the warm up of tubes changed something the same amount of picture raster fade time

As bandersen mentioned, they are interactive, the fields for the focus magnet AND the ion trap, the tube was designed to work with a combination of both to deflect ions away and electrons to the front, as bias is slowly raised, this will cause a respective ramp up in the electromagnetic field of the focus coil, and w/o the ion trap in place, you can expect weird stuff to happen as it rises to full power.

Absolutely. The magnetic fields interact. Always run the set at full line voltage, adjust the ion trap magnet and carry on :)

yeah the only reason for power up was recapping and checking like old radios. The ion trap was in place and close eyeballing where it had been when I took it off but not exact. When I saw it dim out as voltage passed 100 volts, I thought something was shorting out or burning up.

I do not have a 4 mfd capacitor that c207 is and its on pin 5 of the 6al5. Im going to guess a 10uf may work. I might have a 4.7 mfd somewhere but dont remember the voltage of it. max volts on parts list shows 50 volts. WELL I just found it. 4.7uf at 450 volts. Installing it now.

Well I have recapped the 4 mfd cap and replaced my dual caps 153k and 333k that made .05uf twisted together with actual .05uf mpt caps. Focus adjustment used to work, now it doesn't focus or seem to focus.
More possable problems is the 1b3 filament seems way too bright at 117 volts. I know this tube is powered off the flyback so whats up with that? Adjustment way out of whack causing it to draw more filament current or a bad 1b3?

is this tube too bright. I have read that a 1b3 is barely able to throw enough light to be detected unless room lights are off!!!!http://www.videokarma.org/attachment...4&d=1719696058

http://videokarma.org/attachment.php...4&d=1719696058

looks normal to me!:D

you want to see abnormal...
​​http://suzaku.live-evil.org/0317201339a.jpg

gassy 1b3??? I had a philco 80 tube do that untill it failed. I guess I will go back to figuring out what makes focus work. cant get horizontal to lock yet.

Check the power resistor in series with the focus rheostat.

r332 I think your reffering to and that says 3000 ohms on schematic. Checking now. The 25 watt power resistor 8500 ohms in the hv cage is open.
trying to come up with an 8500 ohm substitute in the mean time. 25 watts is definetly a huge one

Yep, they're always open.
You can use a 10K - 20W (or better) in parallel with a 56K - 5W resistor.

the sand resistor measures 1.867k ohms.

I found two 12k ohm 20 watt resistors which would make 6k or just use the one 12 k ohm itself.

The 8.5K resistor in the cage has a big impact on the horizontal linearity. Try both and use the one that looks better, but I suspect you'll need to get closer to 8.5K to get good results.

Was I lucky then that mine was OK? :scratch2:

I guess I will just put the 12000 in for now as I dont have anything smaller or a 56k that will work. Going to order a 10k adjustable 50 watt one.

Im wondering since focus is just voltage supplied from the power supply to the focus coil that a connection issue is up because focus rheostat is good as well as the sand resistor as well as the focus coil itself. I had the tv on its side and ok yeah I got some focus adjustment back, put the tv right side up no focus. Gotta be a connection issue and I suspect that power socket plug rear of tv for starters.
Messed with the horizontal linearity adjustment because it was screwed most of the way out like an inch and almost a half of threads sticking out. I can get picture to stop rolling and almost sync up but not sure what to adjust next unless controls on the back are still way out of adjustment. I tried flipping around the ionmagnet and that made centering a nice bright picture much worse only half the image showed up so I put it back the way it was.
I figured well maybe they messed with the magnet and screwed that up too.
Not sure how the 12k ohm resistor is affecting me getting an actual picture. but focus is still no go.
https://youtu.be/4_xPEqhBqdU