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-   -   ctc16xl roundie (http://www.videokarma.org/showthread.php?t=255016)

marty59 07-20-2012 08:42 PM

Not sure how high your line voltage is but there is another (unused) primary tap on the power transformer if B+ and filament voltages are too high.

timmy 07-22-2012 08:17 AM

does anyone know the specs on the 4 diodes on the sound board in the ctc16x chassis? they call them sr201 up to sr204.

ctc17 07-22-2012 09:00 AM

1 amp 600 volts.

timmy 07-22-2012 09:30 AM

would that be the same for all 4 diodes?

ctc17 07-22-2012 11:07 AM

Yes.
Most people use 1N4007s
You could use1N4005-4007
www.diodes.com/datasheets/ds28002.pdf

timmy 07-22-2012 11:27 AM

yes i think the ones i have here are the 1n4007 and are rated 1a 600 volts. ok great and thank you dan.

ctc17 07-22-2012 11:43 AM

Quote:

Originally Posted by timmy (Post 3042663)
yes i think the ones i have here are the 1n4007 and are rated 1a 600 volts. ok great and thank you dan.

4007 are 1000 volts, even better. Where the old ones shorted or something? I see them replaced in some of the sets I have but have never had to replace them myslef.

timmy 07-22-2012 01:21 PM

they test ok but just wanted to know what goes there because alot was burned in that area incase after getting it done and one fails i know what to put there.

timmy 07-24-2012 03:28 PM

ok i got the varistor and thermistor from mstation today but does it make much difference if the thermistor is 63 ohms cold where the original would be 100 ohms or more cold?

mstaton 07-24-2012 10:28 PM

No. it should be fine. I used those in my other sets with no issues

timmy 07-25-2012 06:03 AM

ok they are going in,lol,lol and thanks again for these parts.

dieseljeep 07-25-2012 12:48 PM

Quote:

Originally Posted by timmy (Post 3042546)
how would you know its from channel master?

Right under the U/L recognized logo there is a 1059, which is the EIA number for Channel Master. :yes:

timmy 07-25-2012 02:35 PM

oh, ok well i learned something new again,lol...

timmy 07-26-2012 04:46 PM

ok the rca new vista is done but i have one little problem when i turn it on its not tuned in like it was when i turned it off a minute earlier. but as it warms up about 40 seconds later perfect picture and sound and its like a tube in the tuner section of maybe IF section is taking longer then the others to heat up. i did sub a tube in the section just below the tuner i dont remember what section that is but is the first tube there, a 6jh6 i subbed to a 6bz6 and dont know if this is why but these sets come right on tuned and sound is there but this one is fuzzy sound and the picture is out of tune, then it comes in slowly and then its perfect. the section i subbed the tube has 1st, 2nd, and so on, i think its the IF section.

DaveWM 07-26-2012 05:02 PM

change the channel, then go right back see if the pic is normal then.

timmy 07-26-2012 05:32 PM

after its on for a moment and all is good ill change the channel then go back is good.

DaveWM 07-26-2012 06:36 PM

when the problem 1st shows up quickly change channels then right back and see if it's ok.

timmy 07-26-2012 06:55 PM

i had tried that in the beginning but no good so after about 40 seconds all is good but this is not right.

timmy 07-27-2012 06:24 AM

i think i may know whats going on here the thermistor i had put in is slow to warmup maybe because of the ratings as the rca should have a thermistor rating of 100 ohms or more cold and around 4 or less ohms hot. the one i put in measured 63 ohms cold and it states .47 hot so this has to be it. but about 35-40 seconds seems like a long time compared to my other sets about 15-20 seconds all on.

timmy 07-27-2012 11:04 AM

well its not the thermistor since i jumped it out and still the same thing.

mstaton 07-27-2012 02:14 PM

Not the thermistor! A few ohm wont make that much difference if any. Probably that subbed tube in the tuner. Subs don't usually work the same as the original. I suggest you buy the right one and try it. It looks nice otherwise. what is exactly slow to warm up? Sound, CRT or both, just the tuner?? If the picture is slow, probably a weak CRT. Do you have full line voltage on it or on a variac?

ctc17 07-27-2012 05:38 PM

I know exactly the issue timmy is talking about. I have several sets that do it, they come up with a blank raster then the sound and picture pop in a few seconds later. Or the set starts with the fine tuning way off then it fades in.

I have never bothered to look into it. It seems like a common issue because I have several sets that do it.

timmy 07-27-2012 06:03 PM

Quote:

Originally Posted by ctc17 (Post 3043088)
I know exactly the issue timmy is talking about. I have several sets that do it, they come up with a blank raster then the sound and picture pop in a few seconds later. Or the set starts with the fine tuning way off then it fades in.

I have never bothered to look into it. It seems like a common issue because I have several sets that do it.

yes your right that is exactly what its doing so im going to look into the video output tube and the tube for agc because if you turn the agc down everything fades and slowly turn it up and it will do the same thing. the 6jh6 is said to be an ok sub with the 6bz6.

timmy 07-28-2012 12:43 PM

does anyone know what an RCA 8 2v tube translates into. thanks.
ok i found out it was a 6gh8a...

timmy 07-30-2012 12:08 PM

Quote:

Originally Posted by ctc17 (Post 3043088)
I know exactly the issue timmy is talking about. I have several sets that do it, they come up with a blank raster then the sound and picture pop in a few seconds later. Or the set starts with the fine tuning way off then it fades in.

I have never bothered to look into it. It seems like a common issue because I have several sets that do it.

well heres one for you dan, i spoke to don lindsly and instructed me to check a few things and this tuner type problem is resolved so you can fix your sets that do the same thing. it was the second tube in the IF section in this case it was a 6gm6 but the kicker is the tube was new and tested excellent no gas at all but it took to long to come on and i also tried a used one that didnt work either so i put the sub in for the 6gm6 which is a 6we6 and it comes right on sound and picture, perfect. and all the sockets including the IF section sockets i soldered so its a weird thing but that sub tube did the trick.:D

ctc17 07-30-2012 02:49 PM

Hmm interesting. Try another 6gm6 if you can, just because the tube is new doesnt mean it doesnt have grid leakage or a short that opens when it heats up to a point. I have run into several tubes that test good and cause problems.

Substitution is the best test for tubes.

timmy 07-30-2012 03:26 PM

Quote:

Originally Posted by ctc17 (Post 3043337)
Hmm interesting. Try another 6gm6 if you can, just because the tube is new doesnt mean it doesnt have grid leakage or a short that opens when it heats up to a point. I have run into several tubes that test good and cause problems.

Substitution is the best test for tubes.

well i did try another 6gm6 and no good. cold or heated it made no difference nothing worked except the 6we6. unless there is maybe a resistor or cap within that circuit that is leaky or out of tolorance and the 6we6 while maybe alittle different in some why changed the needed value of what possibly might be wrong to the point of it correcting the problem. 6gm6 and 6we6 must have some small things that are not the same between the 2 because they both have different numbers. who knows except that it worked out fine.

ctc17 07-30-2012 05:54 PM

Is there static and snow if you disconnect the antenna???

I have a 16 that had a open 150 ohm resistor that fed the first IF its plate voltage.
The set worked fine with no voltage on the first IF tube but kinda acted like you are talking about.

A radical sensitivity to different tubes would indicate a fault in the circuit.

Why dont you do a dc voltage measurement check on the first and second IF

timmy 07-30-2012 06:08 PM

with the 6gm6 in and turn it on there is no snow without the antenna until that part of the circuit warmed up for 40 seconds. i would agree at a radical sensitivity between 2 tubes and your probably right about something in that circuit that is at fault. however i put the whole set together and it plays great for now but i will keep an eye on things for now and if something gets funky then i guess ill be looking for the culprit, with of course my questions,lol,lol..... i forgot what that second tube was listed as but it was the second one.

ctc17 07-30-2012 07:02 PM

The if is a bitch to work on, mostly because it has a plate soldered on the bottom and a cover on the top.
Working to your satisfaction is all that matters.
[I think we need a list of timmys working tvs

timmy 07-30-2012 07:09 PM

ok dan heres the list, and they all work, 1963 silvertone roundie
1964 rca color roundie am-fm phono
1965 magnavox roundie am-fm phono
1966 motorola 23 inch console
1965 or 66 rca new vista
1947 fada b&w

DavGoodlin 08-03-2012 08:26 AM

Hey Timmy,

If you ever get down to Lancaster, I will trade you something interesting for that Motorola 23". I had one, a TS914Y that I lost in the early 80's
Dave


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