RCA console - Page 4 - Videokarma.org TV - Video

Jeffhs · #46 03-12-2012, 01:34 PM

Looks to me as if the TV is overscanning quite a bit. I have never seen a color bar pattern fill a round screen that much. Also, I did not see any burn marks on the CRT when I looked at your pictures of the set in operation. The ion burn must be very small, almost like a flyspeck. In any event, it isn't noticeable (at least, as I said, I don't notice it) on the pattern from the generator or on the pic of the ID screen from Syfy. It may be that the burn only shows if one looks at the picture in person and not on digital photos.

WA3WLJ · #47 03-12-2012, 01:43 PM

That's the Center of the JIG ??!! Not a BURN !!

It looks like somebody marked the CENTER OF THE JIG for you !!!

robdjf · #48 03-12-2012, 03:48 PM

The test jig has a burn in it. Not the 21fj

robdjf · #49 03-12-2012, 04:04 PM

I thought there was something wrong with the crt also. I forgot to plug the degauss wires in. Manually degaussed it and after about 10 min. I was able to get some purity. So with the degauss working I kept inducing a magnetic field every time I turned it on. Talk about shooting yourself in the foot 452 times !!!
Way back in this post the thermistor smoked on the initial fire up. So I replaced both the vdr and thermistor. I matched them up by value and part number with Moyers.
Well they are not the correct ones or no good because of age.
What are good part numbers that should work ?

Jeffhs · #50 03-12-2012, 04:11 PM

Quote:

Originally Posted by robdjf

The test jig has a burn in it. Not the 21fj

I just looked at the picture of your test jig and saw the burn -- as you said, it is right in the center of the screen. The TV picture on the set's own CRT is excellent, if overscanned. I guess I should have examined all photos attached to the post thoroughly before assuming that the burn was on the television's CRT, which was my first thought.

In any event, it's fortunate that the burn mark is not on the set's own tube, as I am sure 21FJP22 roundie color CRTs (or any other type of cathode-ray tube, even rectangular, for that matter) are becoming scarce, and are (or could be) very difficult if not impossible to find in this age of flat-screen TVs.

robdjf · #51 06-12-2012, 04:58 PM

Before I start in the ctc-15 I would like to work some things out on this chassis.
Could someone ohm their degauss coils ?
I haven't done any more adj on the purity or convergence since the crt needs a catarac job and will have to come out.
I wanted to see if I could the chassis right.
I the picture there is a black line between Brian and Stewie that runs top to bottom
half way down you can see it bends. It starts from the top to the bottom.
The whole picture does this slowly.
It does this on the test jig as well.
I swapped HOT and damper tubes and checked my work when I replaced the lytics.

robdjf · #52 06-12-2012, 05:01 PM

Forgot the pictures

DaveWM · #53 06-12-2012, 05:07 PM

is it very slow, like 11-15 seconds start to finish?

DaveWM · #54 06-12-2012, 05:14 PM

have you replaced all the filter caps or checked them. there are some on the vert xformer primary that are decouplers as well.

did you check all tubes for HK shorts

Did you reflow all ground stakes, on the PCB's

Generally speaking a slow moving vert wave (vert line has horz displacement) look for hum and vert osc rate beat freqency issues. I had a maggie like that turned out it had a poor ground connection on the sweep board that allowing heater ac interact with the sweep. The prevailing opinion was a beat freq of the 60hrz vs the 59.999 whatever of the vert osc somehow modulating the horz (the horz displacement). Anyway check out the above.

robdjf · #55 06-12-2012, 06:55 PM

Yes it is slow moving.
I will check some tubes again tonight first.

Thank for the info Dave

DaveWM · #56 06-12-2012, 07:39 PM

oh the way I found the offending part was to feed each section of the maggie with pure 6v DC to the heaters. I used a big ole gel cell battery, started by feeding the entire sets filaments, bingo wave gone, this confirmed it was a filament AC source issue. Next I one by one reattached each filament group until I got to the deflection board where it returned. Sounds drastic but I was a real newb and was totally frustrated by it so was determined to try anything. I almost was going to build a DC power supple just for the filaments but that would be a real cop out. Anyway once I narrowed down to that one pcb I decided to solder on a ground buss using some solder wick. the orig ground was nothing more than a pressure contact of the pcb to the metal chassis thru a screw. I prob could have gotten it going by just tightening down the screw (and cleaning up the contract point) but figured the copper braid would be a bit more secure. I had a more recent "hula" on a RCA ctc 16, I think it was just a bad filter cap but dont remember for sure. It was one of those deals where the filter can tested ok and worked for several months then failed.

Jeffhs · #57 06-13-2012, 12:10 PM

[QUOTE=robdjf;3038522
I the picture there is a black line between Brian and Stewie that runs top to bottom
half way down you can see it bends. It starts from the top to the bottom.[/QUOTE]

The line in the picture you are referring to is supposed to be there, but the bend isn't. There is probably 60-Hz hum getting into the deflection circuits at some point. I am at a loss to explain just where the hum is getting into the sweep circuits, as you said you replaced the filter caps. Elsewhere in this thread (I think directly above this post), DaveWM mentions other caps that could be defective and causing the problem as well. I would replace every filter capacitor in the set, since in a TV set of this vintage they are probably all either already defective or are getting there, slowly but surely. The CTC16 series is from the mid-'60s, so it is almost a certainty that every filter needs to be replaced; since those caps are now at least 47 (!) years old, a complete recap is in order.

DaveWM · #58 06-13-2012, 02:20 PM

the one I was thinking of is a 80uf that connects to the red lead of the vert out primary it decouples the strong vert rate pulses out of the vert circuit so they dont get into the B+. IIRC its a two section cap kinda in the middle of the chassis (3rd on from the end). Its prob open (if shorted you would have a lot of big time problems, starting with a smoked sand resistor) so just to a quick bridge there and see if it goes away. the other section of that cap looks a decoupler 2uf for the audio screens. If that fixes it you would want to take the existing cap out of the circuit, just in case it decides to short some time in the future. I would replace the 2uf as well (same can, if the 80uf is gone then the 2uf is prob not too far away) do you have any sound bars in the set (turn the set up loud and see if you see any interference patterns that seem to modulate to the sound).

robdjf · #59 06-22-2012, 10:18 AM

I found something out while working on the chassis. The wave that I have been fighting gets much better with chassis out of the cabinet and sitting on end (power transformer down). This is why it didnt show up much on the test jig (chassis same position). Last night I put it back in after soldering ground stakes on all boards except IF. I fired it up no difference (wtf). Pulled the chassis back out and sat it on end and the wave is almost gone. I tried gently twisting the chassis to see if there was a change no dice. It has to be a poor or cracked connection.