Rca?
 

http://orlando.craigslist.org/atq/2220903462.html

Picking this up today, free so I guess is better me than the scrappers

That looks like a delta gun CTC8x or 9x chassis from the late '70's. It could also be an inline gun CTC10x chassis from the early '80's, since the design didn't change much during the late '70's-early '80's. I don't think it's old enoough to have the upright CTC68 chassis in it.

At any rate, if the CRT is good, it should make a nice picture.

I am mainly just getting it for parts, I really don't have room for it, but I know its fate if it goes to the street...

I am hoping for a decent 25v delta gun.

Don't expect too much out of that tube, unless it's been replaced sometime in the sets life. Those "late" delta gun RCA tubes from '77-'80 didn't hold up that well. I saw plenty of these sets, when they were younger, with weak and/or shorted CRT's. And, rejuvenation didn't always help. At present, I have a 19" RCA delta gun colortrak from '79 that got a new CRT when it was less than a year old.

here it is. The CRT is a delta gun, the CTC number is rubbed off, all the guns tested ok, but the Blue setting had a much different cutoff, and it did not track well on that gun. I dont know that I want to mess with this.

there is a fuse and its ok, the degausser works, but thats it. I can hear a rapid ticking coming from the side where the fly is, beside that and the dial light coming on I get no sign of life.

oh the CRT is a 25vCZP22

late 70s colotrak?decent sets bit not as good as the earlier xl100s and the fold down chassis colortraks.seems crts went south on these sets.they will take a jolt periodically though.there is a diode in the power supply i can remember that was a problem.same characteristics of your set.good luck with this and i have a good crt if you need it

well for fun I checked the HOT, seems ok (.4v diode mode BC,BE nothign CE.

I will look around for that diode

from what I can tell the AC interlock connects to a board with a fuse, thru the degausser, then a bridge rectifier, I get lost after that. But there is this odd looking can, looks like a small can cap, about 3/4 wided and tall, has 3 thick metal legs. I dont think its a cap, just a guess but some kind of relay in a can?

what you need to do is use a variac and isolation transformer on that set. Pull the regulator board out. Jump out the coil (forget the number of it; it separates reegulated from non-regulated voltages). See if it runs. You have to put 27 vdc from an external supply to start the horizontal.

There is a electrlytic capacitor in the 27v supply that used to go bad. Also, a 680k resistor opens at the regulated coil leads. I made a living repairing those sets. RCA called that chassis the extended life chassis. I called them "no life sets". They did have a great picture.

well that was too easy. the only thing I did was pull the HOT and re-seat.

Also pulled what I think is was the sweep board (just to check some transistors).

decided to put it all back in to look for voltages, instantly got audio noise, (it wad dead silent before),

Bingo

That was so easy I am going to see if the orig owner wants it back.

there is a little bit of noise in the pic, I think its from the conrast control (touch it and the noise comes and goes) so I will go thru the pots and give them a quick cleaning. I was really kind of hoping this one would not work so I could just scrap it for parts. But the convergence is PERFECT, the color bars are PERFECT, I mean better than anything I own. Oy Vey.

the sweep board you mentioned...if it's a board 2inches by 3 or 4 inches mounted on the right side of the aluminum wing, that is the regulator board. Part # 142709

the board I pulled is in the 4th pic on my chassis shot, 3rd board on the right, just above the horz adj (long red pot shaft).

a couple other thins, the horz hold is super critical, it will flop one way then the other. You can get a stable lock, but it only has a couple degrees of rotation at best to hit the right spot (which is in the aprox middle).

The vert lock is strong so I doubt its a problem with the sync sepearater, I am thinking the AFC circuit in the horz. Maybe some drifted resistors or dual diode (I assume this is how its horz AFC works if its like tube sets), perhaps even a weak cap in the feed back pulse, just guessing. I am going to let it run for a while and see how it goes.

This thing would be a "green" tv by todays standards, its barely pulling 1 amp, my tube sets are amp hogs by comparison.

that is the horizontal drive board. Uses a count down circuit. Those adjustments were rock steady. Scope the 27 volt line for hum. Also, if you have a marginal regulator, it will fall out of horiz sync due to the horiz disable ckt. I may still have the training manual. Will give a look see tomorrow.

roger will do. Thanks for the input.

Oh I did find the year made 1977, still could not find the CTC number anywhere else, it was stamped but the stamp is too far gone to read

do you have the model number off the back? A pix of the front of the set? serial number? chassis # is stamped on the chassis in blue print. also, in the front of the chassis near the small ckt board there may be a small label with the chassis number. The video board ..is it a 001 or 002?

oh well that was fun. Back to ticking. I heard it try to start up, then is shut down and not ticking again. I am trying to find the 27v souce to check. More pics coming and model numbers as well

I always plug it into a variac set at about 90 volts and see if it will start. Possibly, it will be easier to trouble shoot.

CTC-86 (it was on a pasted on sheet). It will come on for a second then cut off (you can hear the audio).

well other than the pilot light and the deguasse its dead as a door nail now.

it was coming on for a few seconds then shutting down, but now I seems to lack any B+ anywhere. Guess I will pull the chassis out and check around again. The fuse off the power supply board (right at the interconnect is still in place but seems to have sagged a bit in the middle.

I would be nice to be able to work on the chassis on the bench to at least work out the PS issues, but I dont know how to prevent any damage to the circuits with it disconnected from all the CRT grounds and anode.

Oh and that can on the power supply board (again I think its some kind of relay in a small round can was warm).

very 1st thing I checked is a RCA 142603 sand resistor, 100k, checked around seems like it should be a 3.9 ohm 10 watt (its not marked but I checked on line and with moyers and that seems to be it). Soooo I think I will check my stash and see what I have.

got a 3.9 7w, should be a 10w so I am just going to jump it in later and see if that does it, will get a proper larger wattage resistor later.

well that promply smoked, check the HOT, shorted, Not sure if it uses a bipolar transistor or the SCR in that model. This thing is not long for the curb...

it's a regular transistor ECG238 will work. you have to remove the regulator board, jump the capacitor on the wing by the regulator board, put on isolation transformer with a variac and bring up slowly from 90 to 95 volts. You were going into shuit down mode. If the 3.9 ohm is gone, check the diodes on the input power. The start diodes are on the small board in the front of chassis.

Put a spare HOT in it, dinked around with it some more, replaced the 3.9 again. Its workign again but dont know for how long. leaving it play for a bit to see.

ECG238 man that rings a bell...The 6JE6 of horz transistors.. That was the part that would break the set and send it to the curb when I was working on these sets in the 90s. That cost like $9 and lots of people would say trash the set when you told them there was a chance something else could be wrong that caused it to fail.

you have to read the regulated B+ while it's running. Place the neg lead of the meter to Hot ground and positive lead on regulated B+

there were some test point on one of the boards,(the one in front of the defection board) 21v 27v and 11v

they were very close (+-.5v if i recall correctly). I will check again for exact numberrs and scope as well for ripple.

It ran for hours last night with not issue. I take it the startup is where the problem presents?

turned it on this am, came right on.

:yes:

Got the rifleman on now (B&W), grey scale looks very nice. These set's make a very nice pic.

Just curious, I see on the regulator board the warning about not fixing but replacing. Anybody know what the deal was with that?, I dont see any parts that look special, unless there is something special about some of the transisotors. I did not look to see the PN's on them.

...

critical 32 volt regulator

Are you still planning to deliver it back to the original owner?

They dont want it, just glad it went to a good home. I wish they would as I dont have room for it as is.

I tested the voltages

27=26.73
22=22.08
11.8=12.38

there was a 210 but it tested at 20.92 so maybe that was a 21, maybe I was misreading the board.

on a different board I found another 210 it was 200vdc

I am truely not a fan of the cab style, so maybe a good one to try out my wood working skills on. I have a few others in need of wood work, this could be a test case. I would just make a ply box, fit the front in, laminate some veener to it and add some screw on legs.

Its too bad no one is interested in this era, like I said before it rivals any pic I have seen.

ok maybe a dumb question, but am I suppose to be able to a door behind the tuner knob to setup the tuner? I can't seem to see if there is a latch or something. I will get a close up pic of the front later.

you lost drive to the output and that is what shorted it. i used to just solder the legs of the output to the socket it sits in the base and emitter. that would sole the problem the majority of the time 90%. steve btw i sold a lot of those sets. this was good chassis

Here is a pic of the front