looking down on 12by7 going counter if thats 7 its 145 volts

that cant be right, pull 12By7 the tube out and check that voltage again (with tube out), should be at least 300v

One thought on the HV regulation that only works without video issue: On my CTC-12 clone Silvertone, the HV regulator circuit has a lead (from it's control grid IIRC) that goes to the output of the luminance video amp through a high value resistor. I think that allows the video to have control over the HV, and if that line is bad on your set it could help explain the poor regulation with video present.

I asked him to look for that, think it was a 12meg. I know it was added starting on the CTC-15's

would be interesting to add it to an earlier set just to see if there is any noticeable difference.

I have him running down bias voltage on the CRT. they just seem way off.

I think the best idea is set it up for the decent brightness raster (not using the setup procedure since that does not work). with a solid 25kv from full bright to cut off.

then

get both the silvertones out, and compare one CRT lead at a time mainly looking for the bias between K and G1 and the required screen voltages, maybe even the horz out cathode current. set up both with rasters of approx equal brightness and HV both at 25kv.

tough dogs require really thinking thru the issue, in this case getting the HV under control (by having good shunts that do not short out) is just eh begining.
the hard part is determining just how bright max bright, how strong is the CRT, and whats going on as the controls are adjusted.

where was that 12 meg resistor ?

look around the junction point of the two 1.5 meg resistors, IF your set has one it will be there, but I don't think it is, if its a true clone of a CTC-12. I really doubt it could be the problem unless it has burned and gone down in value. Note it was not on earlier models.

i dont see it on the sams and i dont ever recall seeing anything else besides those 2 1.5 s . could the brightness pot be bad in some way, ill have to check it if it seems that this may be an issue.

with those voltages at the 12by7 not right im wondering even though the issue with the cap in the IF being shorted had anything at all to do with this latest problem by taking something out or a cap or resistor in some way even with the short only affecting a few filiments. and with this problem it does seem like it would affect the hv even in a small way would be a big deal by using up any surplus hv to be used when needed if the crt is being driven hard then there would be a loss of regulation, possible ?

c26 burned what are the odds of c25 leaking in some way or would it have an affect on these voltages?

I dont think there is anything wrong at this point with the HV, if you can get a decent looking raster and 25kv and it stays 25kv as you adjust the brightness up and down, then its working as designed.

The issue I think is a CRT bias prob, maybe a gassy CRT, something causing the problems getting the correct voltages to correctly drive the crt.

The HV holding steady from fully dark to full raster is key. The next issue is why the CRT cathodes (yellow) have to be so low to get the crt to conduct. That brightness range sure seems excessive I think you had -19 to +17 on the grid of the video out tube (based on the brightness pot). I don't recall checking that but it sure seems like a lot.

yes the 19 and 17 with the brightness at max and was able to bring the voltages near where they should be using the bright pot and raising the bias was ok and was also able to see the rgb lines in setup because the bias was up some and helped see those lines . but im sure the set was not designed to have the brightness halfway because if it moves then i would have to check voltages to get it back. almost as if the pot is raising to much, i dont know... as for the hv it starts out under 23kv and warming up it goes up but the key here is it dont jump like it did befor and sometimes it will go over 25kv and other times it wont so maybe there is something else going on here.

you should do some resistance checks of the 12by7 per the sams. the grid adjust the brightness pot while checking pin 2

ok ill do the resistance check on 12by7 per the sams, and ill run the set and monitor pin 2 voltage at the tube while lowering and raising the bright pot and note the differences. just want to make sure i got this, lol, lol.....

you could try this

brightness all the way down

service switch in service mode

advance screen drives one at a time to produce barely visable line

if any color can not produce line advance bias pot just until it does

adj all drives for barely visable line

back to normal mode

advance brightness pot just until normal viewing brightness

monititor HV and see if its holding.

if the above works then perhaps there is a problem with either:

brightness pot
grid emissions on video out.
check the plate voltage of the 6AW8 2nd video amp pin 3 per sams 30v with no signal present.

forget getting the lines as i raise the bias and again the blue rides in with the red the hv is up then its down bias up with the bright up hv droops as it did. i was only able to see the lines befor when the bright was adjusted to the voltages at the 12by7 that were close but its nopt working that way same as befor.12by7 pin 1-392 ohm 2-.530 meg 3 .4- fil 5 -fil 6- fil 7-6.40k 8 -3.44k 9-.4 now the 6aw8a i have a sub in there 6lf8 or i could put the right one back in, pin 3 bright low 43.7v high 38.8 v 12by7 pin 2-bright screen 20.75 v dark screen 12.5 v

12BY7 pin 2 = 20volts? My 12 schematic shows -1.7 volts. Negative in relation to the cathode.

im sorry all you guys this set when its done will be for sure a learning experience for us all, this set i guess has been down the road a few times or someone at one time didnt know what they were doing and really messed it up and now it needs the pros, lol lol... maybe c39 slightly shorted.

dont know if this helps rule out a gassy crt but with the crt cap plug off the voltages at the 12by7 dont change they stay the same as i took the readings again, this time pin 1 has 0 volts pin 2 -12.5 low bright and 20.75 volts bright high pin 7 145 volts pin 8 134 volts. seems there is something else going on in this set because these voltages are certainly not right, since pin 1 looks like it should have 10 volts and #2 and #7 are the other pins with the wrong voltages.

it may take a few days, but hang in there.

I plan to make a video showing all the pin voltages on the CRT of my working well CTC-12 that will give you a good frame of reference.

Note sams voltages can be all over the place, they are way off compared to the RCA field guide as an example.

Esp CRT settings since they have to be tailored not only to the CRT performance but many other variables (not the least of which is individual taste of "correct" brightness).

i went back and double checked the pin 5 of the shunt voltage is 380 volts while pin 2 is 391 a difference of 11 volts compared with 370 and 385 is a 15 volt difference. just figured i would check to make sure nothing else happened there since i had some time to do so. i dont know if a few volts difference there would make much difference with the hv.

I assume you mean pin 1 and 5 the cathode and the grid?

you can run pin 1 up and down with the hv adj pot. this sets up the overall bias and determines the current shunted by the tube. bigger the difference the (cathode pin higher that Grid pin) the less current flows thru the tube (to a point until its cut off completely and no current will flow). Less current thru tube, the higher the unloaded HV will be (assumes CRT is blank and not drawing any). the voltages ref in sams are "prob" just a reading with the a blank raster as most of the time there is a statement about "no signal" and using a VTVM, setup for normal viewing etc...

things to consider, the type of test equipment used (in this case its prob supposed to be a VTVM)
line voltage
no signal (unless specified like in some of the chroma test points, which is typically color bars)
+/- tolerances ofter 10-20%
resistance and voltage readings are just the starting point and not the only thing to look at if something is not working right.

I assume you mean pin 1 and 5 the cathode and the grid?

yes , im sorry this test was with the tube in pin 1 and 5 to ground

i tried that hv pot up and down it dont swing much at all only a few volts on the grid. your opinion, about putting the 2 1.5 m resistors back in which are now 1.6 m would this just lower the hv overall or leave the 2- 1 megs in if it benefits the hv circuit.

I don't like to re engineer tv's so I would put the correct resistors in there.

That being said other that I think it will work the same, just with the HV pot in a different position to get 25kv. You will just be moving the math around a bit on the voltage divider requiring resetting the HV pot.

i have a bit of a problem the 6gm6 has c25 and c26 off pins 3&4 these caps go to ground the sams shows nothing else but 3-4 to ground but i am getting k readings on both pins to ground, this is not right as a .001 should not show anything to ground. this tube is ccw as the rest ? im seeing 81 k on both pins to ground..

i have a bit of a problem the 6gm6 has c25 and c26 off pins 3&4 these caps go to ground the sams shows nothing else but 3-4 to ground but i am getting k readings on both pins to ground, this is not right as a .001 should not show anything to ground. this tube is ccw as the rest ? im seeing 81 k on both pins to ground..

if the filament wires are attached to the board then you are seeing the resistance of the B+ voltage divider to ground that is used to float the filaments.

ok that makes sence but in your video the voltage you had at pin 1-2 showed 211volts mine shows 220 volts closer to the 225 v limit 211 v would be better i would think.

maybe i should have changed them both c25 and 26 to be safe. if the other cap was leaking just a little bit , would this affect the heater voltage or the voltage at the shunt, like the other.this other cap is on the side of the resistor divider.

lift the all the leads off the junction of the 150k/180k resistors and read the voltage, should be around 180-190v

reattach the leads, it should not change. if it does then there is leakage, somewhere. could be those caps to ground (.001/.001/.1) or a KH short in a tube (the IF tube/shunt tube/CRT).

if it does not change you are good to go.

if it makes you feel more comfortable to change by all means have at it, just make sure the cap is rated at least 400v to be safe (double what it is likely to see)

i just want to cover all i can and not overlook anything. i took the 3 tubes out that use the z y connection but i would still have to remove the connection from the diode and the gound via the resistors then check those z y heater leads to ground there should not be anything readable, i hope. i will change the other cap .001 i will use a 102k 1 kv its supposed to be a .001

TAB BOOKS NO 496
RCA COLOR TV SERVICE MANUAL
BY CARL BABCOKE.

Timmy you MUST buy this book, often on ebay for $5-10$

it explains CRT bias and HV regulation the best I have ever read.

I was reading that book, the low side of the brightness pot should be -14 the high side +12. Check the peaking coils right by the 12BY7, the -14 is pretty close to what you have the high side seems too high (+20v not +12).

this could be an open peaking coil or a weak 2nd video amp.

check L12 and R61. What value do you have for R64?

ok ill check those resistors. and the 2nd video tube would be the 6gm6 at that cap that burned but i put another one in there. then there is the 1st & 2nd videotube which i also changed so i would think that rules the tubes out at least for now until i check the other components. ill check again but i have checked r64 several times in the past to find it was good. ill get back to you on the others.

ok this is what got here, L12 tests at 6.8 ohms compared to 6 ohms, c39 reads infinity, other .001 at the 6gm6 tube tests good so i left it in there, L13 however didnt test so good , 6.5 ohms down from 2200 ohms, ( 2.2k ) so i know now i need this coil 2200 ohms 120 uh . r 61 1185k ohms sams shows 2200 ohms , r 64 .732 meg looks good sams shows 680k

the L13 is fine they are giving you the value of the resistor not the coil another of sams errors of omission. I was taking a long shot trying to see if there is any reason the hot side of the briteness control was so high. I dont think there is a problem. More likely just some tube issue (weak) in the 2nd video amp.

that book I mentioned goes over much of this in great detail. I did not see one listed on ebay currently but if you check back I am sure there will be one, they come up all the time, remember it has to be the 1st volume by carl babcoke on rca color tv's.

so L13 measuring this is ok, ill put it back in, bty there is only 2 legs on the L13 so how could anyone tell if its bad. and the brightness pot measures 242k .

fyi for future ref, you generally do not need to pull peaking coils out just check them in circuit, you should see low ohms.

fyi for future ref, you generally do not need to pull peaking coils out just check them in circuit, you should see low ohms.

ok, good to know as these boards are so brittle and i hate messing around them, traces break, ect...

the 3rd video tube 6ej7 on my tester has the grid emission needle jump up in to the area of rejection but only when i press the button it then goes back down and also the neon light that indicates shorts flashes when the needle jumps. would the 3rd video tube possibly be responsible for the 20+ volts on the video out tube ?

nope dont think so.
I will be doing a video later to see what it normal

Hi Guys, sorry I was all tied up for the last few days.... I've read all the fun
since I was here last, and it seems to me you guys have not resolved the odd
voltages on the 12BY7A....? If that is correct, I was wondering if you checked
the following resistors.... R146, R148, and R139 See attached images so we are
all thinking of the same parts....

Just in case it's not an open feed to the plate, but biased to that 20V grid take a
look at C729, when you follow the path through R133 and L708 it runs over to
a 17V point on the Sync Sep 6AK8 and AGC control 6K 2W, that's got to have
a very influential amount of current.... So if'n C729 is being bad, that could
take the grid strongly to 20V..... Wadda-ya think....?

Heater and other stuff tied me up at wife's parents house, snow might do it
to me for tomorrow, let me know if you got that 12BY7A under control....'OK'

.

The .1 in the grid circuit could cause a prob, but none of the ones I have ever worked on have been bad (leaky). I hesitated bring that one up for that reason AND the fact that its in a kinda busy area of the circuit board.

I am pretty sure he says he has checked those power resistors around the setup switch. one easy thing to check is to see if the plate voltage goes away from the 12By7 in the service mode. It should not, but if it does one of those resistors is bad.

Hopefully the problem will be resolved with as little need to remove parts as possible to test.

I am going to be making some videos later, and will be checking voltages both a the CRT pins and the video out.

what was the plate of the 12by7, #8 or 7 . ill check to see if the voltage goes away in service mode but yes i did check those resistor around the service switch all but one i didnt cut from the circuit because being very close to the service switch, but ill have to check it for sure. i did check it but all and all i may have got a feed back reading in circuit. the.1 cap is this the cap at the grid of the shunt tube ? im sorry im editing again, i guess the .1 you talk of is the one next to the 12by7 i check in my simple way by using the dvom and it went to infinity .

Anything short of a vintage eye type cap checker such as the Heathkit C3, is a lousy way to test capacitors. Most caps will fail from minute leakage currents that are too small to measure on a modern low voltage device. Caps need to be checked for leakage at full rated voltage for a test to be meaningful.

Did you change out that tube with one from your other set....?
You should not leave any item overlooked with this set, as it already
looks like no one here has yet to see a similar problem like the
ones you are having.... And it took quite a long time to make the
progress already made....

There has to be a reason that tube grid has +20 on it..... I would
focus on that first.... It means that tube is on - hard on.... And the
plate voltage should be low..... First cause is that +20.

I agree on those Heathkit Cap checkers.... I got a IT-11 I think it is....
smaller one than the 3.....

.

Did you change out that tube with one from your other set....?
You should not leave any item overlooked with this set, as it already
looks like no one here has yet to see a similar problem like the
ones you are having.... And it took quite a long time to make the
progress already made....

There has to be a reason that tube grid has +20 on it..... I would
focus on that first.... It means that tube is on - hard on.... And the
plate voltage should be low..... First cause is that +20.

I agree on those Heathkit Cap checkers.... I got a IT-11 I think it is....
smaller one than the 3.....

.yes i changed that tube for sure. and yes the focus now is this new problem with the voltages on the 12by7 and i dont want to overlook anything at this point at all.

L13 shows 2200 ohms in paralle with the coil so how is anyone able to check this if its inside the coil , it measures 6.5 ohms ?

right now no voltages go away from the 12by7 with the service switch in service mode. so now i am going to lift one leg on each of these 4 resistors, r- 60, 61 ,62 , 63 , and check them. why would a resistor show it as 150k but under that it shows 270k,are they saying it could be either one ?

ok r-60- 10k =12.40 k 61-2200 ohm =2335 ohm 62 150k = 156k 63 330k =.330 meg i guess they are all good, something is bad here, where the hell is it, lol,lol.....

any possibilty that the L22,24,26 coils may have anything to do with anything ? i ask because i once took one of these off the board to repair one wire inside thinner then hair and i was lucky i had a magnafying glass. who knows what was done to the set befor i got it maybe things were shorted out like the .001 cap and the focus coil got hot, im just grabbing at really small straws.

Hi Timmy, See posting #291, That capacitor C729, take one leg out of the circuit, or remove
it completely and turn the set on and see what the voltage is on the grid of 12BY7A, if
it's still around 20V then the problem is in another part.... Check that first please...

I don't have a Sams for this tv, just the ctc-12 schematic off the internet, so you
have to use the images I put up to see what parts I'm talking about..... And I can
only follow you if you refer back to those part items the same way....
Also you have to understand tube function.... -7V on G1 turns off the tube.
Anything above that begins to turn it on.... +20V It's ON really ON, so it is to
be expected that the plate voltage will be low because the tube is conducting.....
The only other thing I can see checking is R720, a 220 Ohm resistor in the cathode
of 12BY7A. to be sure it's not open....

On resistors in parallel, There is a formula to figure out exact value, but as a
general rule:

30 ohms || 4,000 ohms you will read close to 29 ohms
10 ohms || 20,000 ohms you will read close to 10 ohms.
200 ohms || 200 ohms you will read close to 100 ohms...

Coils, for the most part are going to be low ohms, 30 ohms or less....
a lot of times they are going to be less than 10 ohms....

A lot of times you can check some items in circuit, but it takes time to learn
what you can, and can't and what to expect. Capacitors block DC and pass
an AC signal, they charge and discharge. In the case of this problem, I am
looking for a reason for the grid to be close to 20V, I can see a path to
a 20V source IF that one capacitor is shorted.... So it is wise to check it and
get that possibility out of the way....


.

ok i have in this circuit a .1 but the rca shows a 0.1 so ill lift one leg and see what happens. then ill look into that 220 ohm resistor off pin 1 .

in circuit the 220ohm resistor measures 216 ohms and lifting one leg of the .1 cap made no difference. dont forget i have the chassis out not plugged up to the yoke. there are 2 disc caps 390mmf in between that resistor , dont know if this may be of any concern. it is a royal pain in the !##$@#$$ ass but if i have to left legs out all over to find this problem well then i have too.

Ok, coming off pin 2 R759 do you have 20V on both sides of that resistor...?
What voltage is on center pin of brightness control..?
What is on R733, either side...?

You are running the set with what no HV...?

No one is asking you to lift every cap, just ones that may lead to an answer...
Sorry you are the one stuck doing it all..... :)

Found cool little website while looking up 12by7a to be sure pin numbers are
right.... Pretty neat..... http://www.intio.or.jp/jf10zl/index.html


.

r733 is the 2.2k 38v one side and 25.5 other. no hv hot out. r759 close to the same. bright max 30.32 volts low 23.04 volts. i have a funny feeling this excess voltage is coming from somewhere else further down the pike .

Not quite what I expected.......

Can you check the AGC pot, 6K 2W.... Be sure it's good....

And can you check the voltages around the sync sep. tube....

Images included....

.

6ka8 pin 1 86.7 v pin 2 24.65 v 3 25.42 its high even by the sams i have here. agc pot 2601 ohms end to end wiper 6.18 varys.

Ok Timmy I got a funky project for ya-
I need you to find ground points on the PC boards where both of these tubes are, and
do 2 things.... With the tv turned on, measure voltage from the PC board ground to the
metal chassis ground, and see if the grounds on the PC boards where these two tubes
are have and voltage on them..... Second, that AGC pot, 2.6K is not the 6K my schematic
says it should be.... You may need to see what's going on there.....

For the 6KA8, cathode ground should be directly through the AGC pot...

For the 12BY7A, C750 - one side goes to ground... Now you have to use a part,
not the metal lugs that the circuit board is attached to, these are clearly grounded,
but just in case there is a trace broken, and it's a long loop far away from the
circuit board connections to the metal chassis.....

It's really strange for so many voltages to be off and the set still works - kind-of.
So we gotta look for some sneaky thing.... And high voltages like that,
especially on items that should be going low, kinda make me thing bad ground.....

.

the agc on my sams says 6000 2 watt which is this set. the grounds of the 12by7 and the 6ka8 from chassis to the ground of the tubes with tubes in ?

Yah, don't take them out...

The tubes won't have a ground, you gotta find parts on the PC boards that go to
ground on one side, and just check to be sure electrically, they are really grounded.
One way is to check the grounded part, to the metal chassis for any voltage....
It sounds strange....

Take a look at C750, it's one example of a part with one side going to ground.

On that AGC pot, disconnect the two legs that do not go to ground to test it....

AGC pot, pins 1 to 3 should be 6K thats 6,000 ohms.... The wiper will
change as you turn it you know, from the wiper to either pin 1 or 3....

.

on mine 2 legs tied together go to ground and has one wire on one tap.

yes I have it too.... Just be sure it maxes out at 6K, and trims down all the way to zero... as it is in the circuit....

.

Ok, more goofy stuff for ya-

Please check the voltage at pin 7 of 6BZ6 V301. Schematic says it should be
around 35V.

Please check the voltages on both sides of R307...

Please check the voltages on both sides of R312, and pins 7 (165V)
and 2 (0V) of 6EJ7 V303....

Is that AGC pot mounted on the PC board or is it mounted on the metal chassis....?

.

ok pin 7 of 6bz6 38.7 v both sides r307 38.2v and 0 v r312 4.17 and 0 v 6ej7 pin 7 155v pin 2 0v

ok pin 7 of 6bz6 38.7 v both sides r307 38.2v and 0 v r312 4.17 and 0 v 6ej7 pin 7 155v pin 2 0v

Gotya - Are you sure - absolutely sure R 307 1500 ohms 1 Watt resistor has
38V on both sides of it.......?

.

no the last post says 38.2 and 0 v .

Ok.... Dammit got excited for a minute....

Ok, So please check the voltage on pin 3, 6, 7, and 9 of 6KA8, V503A.

So Timmy, When you watch TV and the scene changes and goes from light to dark
and the picture blooms out, this is a problem you can easily replicate by turning
the AGC on a normal working tv.... Poorly adjusted AGC often make for a really
bad picture - especially makes them look like they have too much contrast, or
not enough.... It's possible, you have a AGC circuit problem here.... I have not
had that much experience in the AGC area.... Not sure entirely how the circuit
works, so outside of looking at known voltages I'll have to get out one of my
books and do some reading....

I was hoping for a bad ground, but there may be something funny going on
in AGC, and it's driving the 12by7a nuts too.... Gotta do some thinking...

Maybe someone with some smarts on this area has something to say....

So when you take the signal off this tv do you get snow....?

And is that AGC control mounted on the PC board, or metal chassis...?

.

well the agc appears to work properly and so does the contrast. 6ka8 pin 3 22.95v pin7 21.73v pin 6 .702v pin 9 36.2v

this whole thing is just nuts and besides im sure these voltages are dependent upon the chassis being all plugged into the convergence and yoke and the voltages im sure may depend on where a certain adjust pot is, like contrast ect. these voltages on the schematic , does this mean a working set, with all hooked up ? as crazy as these voltages are it still gave a watchable picture.

Does that pin 6 voltage match your schematic....?
Mine is not that clear for that pin.....

Yah, I'm not too crazy about the chassis being out and not hooked up to all it's support crew....


.

my sams show 2 volts on that # 6 of the 6ka8

i kind of thought maybe i make a mistake when i recapped maybe reveresing 140v for 160v , i dont know but maybe i should take the time and check, i really dont know.....

ok heres the latest now, i checked the source voltages and all the voltages are good with the exception of the 160v source and the 140v source. the 160v is testing 129v and the 140v is testing 129v also. i also checked all the high wattage resistors between the different voltage sources, all good . checked the caps and connection for the both voltage sources, cannot find anything wrong here. these voltages are on the IF board, chroma board, and verticle board, all the other voltages are ok. there is a 140v source going to the 6gy6 z demodulator pin 6 but when i pull the tube i then get 140v back in it drops 10 volts. maybe this is all correct and places on the board consume voltage like it is just idling with no yoke or crt connected but i thought i would check my work on the recapping. i am so lost here as to why nothing has been found bad yet.
maybe at this point i should figure the right voltage at the 12by7 by setting the bright pot then check resistance on the pot and make up the difference so that the pot can be at max because if i leave the bright in a specific spot after the voltage was set by the pot and it gets turned then its back to square one. this is so not right to do but what else is there to do, obviously there is something wrong here that is being overlooked, and its got to be a simple but yet a criticle thing going on here.

the hv starts coming up really high and fast almost the way it is supposed to with the hv pot alittle over the half mark but at the same time the voltage comes around on the 12by7 where it is not right suddenly the hv drops low. so with the 140v and 160v sources not right but low it almost seems that the 2 are related , seems like a short of some kind pulling hv and the 2 sources down together.

It must be the re-materialization buffer override computer..... I'll get Scotty on it
right away.... He should be able to fix at before 12-Midnight !

.

when a disc cap shows on the sams as a 150mmf but the spot for the voltage is blank what voltage would this component be. 150 mmf , would this translate into a .0 something ? if this is 150pf what is a suitable sub..

Hey, been nursing our old cat for the last few days. Don't have the ability to do much of
this stuff recently.... pf I believe is 12 zeros.... uf is 6 zeros. I would have to check the
book, but I'm pretty sure I can remember that little bit... So yah, if you have something
written 150 mmf then it's the same as pf. 150 X 10 - 12.

Those disc caps are pretty cheap, so I bet most are 600V or better..... Unless marked...

.

brightness range video

see better link below. Not sure why I keep doing that (google sign in), thanks for fixing that for me SB.

Anyway I wanted to start with a video showing how my brightness pot works, will follow up with one showing pin voltages and HV regulation. The idea being to see how the range of voltages behaves on my set as a ref to what timmy is getting.

One of the points I was trying to make was there is only really about 1/4 turn of useful range. I finds some sets have better range, I think it has to do with how strong the CRT is. This one takes a couple minutes to get to the level seen in the video. This CRT wil have decent emission per the CRT tester BUT the cut off is just barely ok, I can just barely get it to the cut off line. Perhaps the lack of good cut off control limits the effective range of the brightness pot.

Same video minus the google sign in...


https://www.youtube.com/watch?v=CEux-SWHgvs

.

is a n150 the same as a 150 pf disc ? i dont know what the n is for..

ok heres an update, and this will likely be the end of this silvertone saga. i will post screen shots tomorrow. but now the 12by7 would not shut off , driving to hard, so pin 2 of the blanker tube was at -80 volts and thats good but getting to the video tube it still would not shut down . it turns out that the -80volts used to shut the tube was not showing at pin 2 of the video tube, since this voltage is needed to work the tube via the bright pot it was still to high. so i checked that path and looked good all resistors to from and around still nothing wrong. so i went back to the sams and went over my work, all was good, all but one cap in the b+ , the 140v source, the chassis cap showed on the old cap as 250v 20uf so it is said to put back what was in there in the first place so i did. but i put a 250v 33uf cap since that looked like it would cover it all. but looking at the sams it showed 250v 100uf so this kind of explained why the 140v source was low it seemed that there may not have been enough capacitance to allow all circuits that used the 140volt source to work properly. so all i had was a 450v 150uf cap and thats what i put in place and it seems that half of the 12by7 didnt have the push behind the 140v source, and not having enough to go around. this is my thought because after changing the cap these voltages all fell into place. the sams says pin 2 of the video tube is -5 and its right there now and no drive lines, just the blue faintly because the blue is up alittle high to get a good black&white picture but ill readjust that tomorrow befor i post the screen shots. as far as the hv , well the adjustment pot is maxed and all i get is just shy of 23kv, not enough but enough to handle white scenes and the kine bias is ccw. good focus and the hv shunt after watching my other silvertone that when the hv is varied the heater would get bright and get dim so now with the bad silvertone at times the heater will do the same when varied but not all the time so something there is still wrong and it just might be a gassy crt and nothing to do about that. so as far as i am concerned the hv regulation is working now but if the crt is infact gassey then ill have to live with that. with the service switch in set up mode the red up and had to increase the bias to see it then the others came up good but i didnt leave the bias up because if i did the hv dipped and bloomed but i was able to raise the bias more this time then befor and this is why i feel the hv is working and that it may be the crt. its not super bright but has a much better picture whites are white and it dont pull in from the side anymore when befor it did. so it looks like this is what im left with, low hv possibly because of the crt because there is nothing else that seems to be pulling the hv down and the shunt tube is not very hot at all. i will try another new shunt tube in the near future just to completely rule that tube out.

well im probably wrong about alot here since i compaired the rca with sams and rca also uses a 20 uf cap for the 140v source so i checked the cap i had in there it was a 250v 33uf and it tested 32.96 uf, so that cap was good so now i am at a loss as to why the voltages all came into place after changing that cap.:scratch2::smoke:

ok here are a few screen shots it wont be better then this, since this is the best its ever been. even with the hv at just touching 23kv thats all i can get but it is steady.

Put a fork in that, its done.

Put a fork in that, its done.

lol, i thought about putting a bullet in it,lol. hey thanks alot again for all the time trying to figure out what was going on with this set. does it look like its lacking anything ?

looks good to me.

Hard to complain when they are working that good.

Nice work!

-WOW- That has a good picture.......

Yah a week ago I might not have wanted to put a bullet in it, But If it did catch fire
I would have suggested just roasting marsh mellows over it..... You and Dave
did a great bunch of work on it ! !

.

hey i do thank all you guys for the amount of patients with me and my crazy problems with sets i know i would not have got this working as good as it does now had it not been for everyone here that pitched in and helped me, thanks again. the next one is the maggie but after all of this i may be able to handle this one on my own, ill see, lol,lol...

well just for the hell of it i took the 1.6 resistor out for the hv adjust pot and replaced it with a 1meg and now i got the proper hv adjustment via the pot bright down 25kv bright up stays steady and now i can set it at close to 30kv if i wanted, works perfect. and dave how you managed to locate that burned cap even not here around the set amazes me even me having this set for close to 4 years and i never knew that bad cap was there. again thanks:thmbsp: