Goodmorning everybody!

[Bobby Brady]

I am Bobby and I have been fool'n with electronics since I was a little kid. I think this place is a great way to spend some time! I am very pleased to find others with similar interests. I am in Florida now and I got a few old time TV's and stereos I am going to restore. Currently I am working on a project to serve senior citizens but I have extra time for this great hobby!
I love the info here on the rebuilding of those early round color tubes and the photos of stuff like the '64 NY fair and the many older sets. I hope to get to the next TV convention. I am still looking for the photos from the last one.
Soon I'll post a list of some NOS RCA parts I need to get rid of for shipping costs. Amoungst the many things I seem to have in common with you guys is that I am in need of more storage space!
This photo is of a RCA ctc-15 that I believe has had somewhat little usage judging by the amount of original tubes and lack of dust on the CRT and chassis. I think the flyback is an original RCA replacement because of the HV cage missing a screw from being removed at some point but seems to be running well and cool so far. I put new electrolytics in the main power supply and still have to get that special stuff to clean the controls etc. The CRT has a week red and blue gun from rejuvenate'n when it should not have been done(another long story) but I think it will produce a good picture whenever I get this vertical problem solved. I subbed the main electolytic near the 6GF7 (C4 50mfd) but no difference. It could be the 6GF7 but my tester is on the fritz and my gut says it is some resistor, so, I checked most of them and found a burnt(open) 1/2watt 150k that connects a tab of the vert height to a tab of the vert lin(R105). I was feeling good at that point telling a friend we would likely see a full picture but I was wrong! No big change but maybe the picture height went from like a half inch to 3/4". I can see snow or the broadcast signal so I do have a short picture but the photo may sort of look like lines. If I disconnect the yoke it goes to lines. I read somewhere here that someone had put a new vert output trans in a ctc-15 and I just hope I don't need one. I think it would be just a line if the trans was bad. I have started to check voltages but my extra digital meter only goes to 200vdc. My main RCA senior voltohmyst is also on the fritz.
It is exciting and frustrating to be so close to a full picture but so far as to wait to repair the test equipment to get it done! Meanwhile my living room may never be the same. I bet many of you can relate! LOL.

[Manitoulin]

Welcome to AK.

[bgadow]

Welcome! Glad you're here-the more the merrier!

I had trouble with a short pic on my -15, but it was not that short. There was a bad resistor in the circuit with the vert lin/vert size controls but it was larger than what you found burnt, I think 1M or more. Seems to be a common problem for some reason.

[Sandy G]

Oh, Gawd !! ANOTHER old TV nut...I tell you, them guys is gonna take over...<grin> Welcome, pal, to AK- There's ALL KINDS of us "Old TV Nuts" here...Meself included !!

[Steve D.]

Bobby,

Welcome to the AK fourm. Here is a link to the 2006 ETF convention pictures.

ETF - 2006 Convention
Address:http://www.earlytelevision.org/2006_convention.html

-Steve D.

[Bobby Brady]

I was going to give up til I get my test equipment repaired but I checked a couple more resistors and found an open 1/2 watt 82k(R110Sams). I told my friend I would almost bet money it would work now and it did. It was a greta feeling to see the screen come on full! This resistor was not burnt as the other one was. I wonder if one was fried from operating the set previously with the original hot electrolytics? Maybe the other just went out from sitting a long time? Vertical seems good now. I now think the flyback is likely original because the HV cup has been changed probably caused that cage to be loosened.The flyback got fairly hot to touch after being on for like 30min or so. I will soon get all set up to verify the currents. I guess I'll make a bunch of resistor checks. I hope it's just a resistor causing the brightness to be very low. I think the CRT should produce a bright picture because when I shut the set off the screen shows lines coming to a close in the center and they are very bright. I'll post photos as it gets better.
Thanks again to all.

[Dave S]

Originally Posted by Bobby Brady

I hope to get to the next TV convention. I am still looking for the photos from the last one.

Bobby,
Welcome! And here's a bunch of photos -- some unseen until now -- from the 2006 Convention: [link to photos]. Enjoy! Hope to see you there next year.

--Dave

[Keefla]

make sure to keep us up to date on the progress and post plenty of pictures! There can never be too many pictures in a thread as far as im concerned (and im sure others will agree).

[blue_lateral]

Welcome!

John

[Bill R]

Welcome,
You need to check the horizontal output current draw since the flyback is running hot. You don't want to toast it. It looks like there is still not quite enough width and the pic is not all the way to the bottom. Likely you will need to replace all the electrolytic caps and any paper caps in the set. A leaky cap may have caused the death or the resistors. Check the high value resistors in the sweep and high voltage section. I would carefully change all the caps first, then see how things looked.

Bill R

[Bobby Brady]

Hi Bill,
Thanks for the advice. I did change all the metal canned electrolytics and I have the wrong value resistors in the vertical circuit. I am only having the set powered up for short times til I get set-up to check the 6JE6 current draw. The flyback seems to get very warm but not hot. The width may be effected by a temporary wirewound resistor in place of the horiz centering control that was burned. I have another on the way but I am presently stumped with the low brightness problem. Maybe I'm wrong but I thought since the screen lights up very bright when the power is turned off and the picture goes to vertical lines closing to the center that that would mean the CRT can produce a bright picture. So, I am hoping my CRT is not the cause of low brightness. The CRT tester says 2 guns are weak but even turning up the strong gun seems not too bright. I found about 8volts on pin 2 of the 12BY7 where the Sam's says it should be -5volts. Is that why it's dark? I tried changeing the .1 cap and a couple resistors so could it be the 12BY7? My tube tester is not working.
Bobby

[oldtvman]

looks like a demodulator problem, those sets had problems with the chokes in the demod circiut going open, and don't forget that on those old sets one of the first things to do is use a good silicone based controls cleaner and clean all the pots and also the service switch, too many problems seem to be major, but also check the simple stuff first. you may save yourself a lot of headaches.

[Bill R]

I agree with oldtvman don't overlook the basics. Controls switches and tube sockets must be clean. Check for bad solder connections at the tube sockets, and the circuit board ground points. Try to do a gray scale setup. Turning up the strong gun probably will not tell you much. If you can not get proper gray scale, the crt may be to week. I don't think the horiz centering is the problem with the width. Width is effected by the horizontal efficency adjustment. In other words you may have given yourself a couple of clues. If the flyback is running hot, you are drawing to much current in the horiz output. This will cause insufficent width. You will verify this when you check the je6 cathode current. This could also cause low high voltage (dim picture, bad focus etc). You need to get that test equipment up to par. You will definately need to measure over 200 volts when working with tubes. Also be sure to check all the power supply voltages. 405 volt source could be low. Does the brightness control work? What about the service switch? I would expect a negative voltage on pin 2 of the 12by7. This comes from the grid of the blanker tube, a 6gu7 whose other half is the g-y amp in the demodulator circuit, through a 680k resistor.

Bill R.

[Bobby Brady]

I had purchased NOS electrolytics that are exact replacements for the 4 cans in the set. They were "reformed" and checked by a pro. So, I thought I should have a good chance to have good voltages from them. I have been wanting to get a picture on this set for some time because I practically dream about it working like a ctc-15 in another thread owned by Charlie. He posted a photo of it working with the beautiful Endora in living color! I keep telling myself I can get this one to look like that. Just having it work as good as it does gives me a great feeling of accomplishment. Now, if only I could convince others that I am not crazy! The set is basically unwatchable so far but shows great potential.
I am waiting to get that Deoxit for the controls and swithces. The tuner works well as it is. Some other controls are dirty but seem to function. The service switch works but I have to have the kine bias to the max. I looked at the solder connections which all look good and usually I can see the cracks. Gray-scale seems to be very good. The width becomes more full after a couple minutes and the flyback stays rather cool. I reported it got hot but it seems that was only when I operated it for a short while with the hi-voltage adjustment changed so I put it where it was. I had the chassis on it's side for much testing and the main power transformer got so hot I could not hold my hand on it. I guess that's normal? I need to check the voltages at those NOS cans but it'll take me awhile to get my meter working. I am tempted to jump the caps with others to see if it puts the picture brighter, etc. I have an AC hum going constantly from bottom to top like a water wave so I think it is one or more of those new caps but I hope I find something else. There is that one on the vertical board but I suspect it is good.
I pulled the 2 6gh8's to put another two in while the set was on and when I was putting the chroma bandpass amp I had it a pin or two off and the screen lit up very bright. I also smelled a resistor burn a bit too. I hope that smell was not a coil. I am usually much more careful than that! At least I admit my mistakes! It did not seem to make a difference but I must have one or more burned parts now.
I had expected to buy those RCA parts on ebay but I missed the end time. It had the NOS horiz centering control I need. I will write the guy who got them and hopefully he will sell me it. Does anybody here have a burned out flyback that I could buy the red fiberboard with the centering contol from?
Thanks

[Bill R]

I would not trust "reformed" NOS capacitors. I would either wire new ones under the chassis and leave the old cans for looks, or restuff the old cans with new capacitors. The key is NEW not NOS. The hot transformer could indicate capacitor leakage, and that would be confirmed by the hum bar in the picture. Looks like the 3.58 oscillator is not running from the color bars in the pic. You could have burnde something with the misaligned tube. I wouldn't worry to much about that now, I would just turn the color control all the way down and work on getting a good b&w picture. Do you have a CRT tester? You said you had to have the screen bias on max, that would indicate that the may be just weak. Again though if the power supply is not up to par that may be the problem

Bill R