RCA CTC-7 Found! - Info Needed...

[classicradio]

Originally Posted by Steve D.

Here's a link, courtesy Ed Reitan's site, to a catalog picture of the "Anderson".

http://www.novia.net/~ereitan/Galler...nderson300.gif

Notice the legs are not very long. These brass tipped legs are available in most Home Depot type stores and can be stained any finish. There is some ventilation through the bottom of the cabinet so you might want to install legs before warming the set up.

Good luck with the restoration.
-Steve D.

Home Deopt? Seriously? I never would have guessed! I will definitely check them out this weekend as well! Thanks for the tip!

[classicradio]

UPDATE:

I was finally able to power up the chassis tonight, but so far the results were not good. The previously jumped fuses were not blown and of the correct amperage, so I thought I was in the clear. I checked all of the tubes (except the picture tube) and found 9 of them were bad, many of which had shorts. After replacing all of those I replaced the two 3-section electrolytic cans and powered the unit up on the variac.

I had read on various other posts that many of you do initial power ups without the high voltage section. To me this meant disconnecting the tube and removing the 6BK4 and 3A3 tubes from the high voltage cage.

Current draw was looking good up to 90 volts where I stopped for a second - only to watch the high voltage fuse pop with a nice blue spark. I assumed the high voltage section was isolated because I left the tubes out but obviously I was wrong. Any tips? Do I need to perform a short check around the flyback or was my leaving those tubes out a bad idea? Maybe I should have yanked the 1V2 and 6BK4 as well?

Anyways this is an early indication that something is wrong. Any assistance will be greatly appreciated as this is the most complicated radio I've ever seen!

[andy]

---

[classicradio]

Well if the cap for the 6BK4 was laying against the high voltage cage could that have caused a spark? There was no audible evidence of one.

I replaced a few suspect caps around the 3/4 amp fuse (BTW Radio Shack is the only place that stocks these anymore) and powered the set back up with the 3A3 and 6BK4 back in circuit, 6DQ5 and 6AU4 removed. One strange pop but no blown fuse up to 120V. I also got a strange knocking sound from around the high voltage cage - not the sound of a spark but more like the sound of an oscillator at around 5 Hz.

I put the set together and powered everything up on the variac. I reached 110V where I began to hear untuned station static from the speakers, and the high voltage scanning noise came up shortly thereafter. Within 10 seconds of that happening I began to hear a rush of static around the set so I powered it down. It sounded just like a sweater fresh out of the dryer if you know what I mean. Not thinking this is normal I powered the set back down but so far I can't find any problems. The flyback looks like new compared to some sets I've seen - so i don't think that is the culprit. Also, I never saw any static or picture.

Any ideas?

[classicradio]

Well okay apparently just not being a scaredy cat helps.

I powered it up again assuming the static was normal and after adjusting the tuner I did get audio and some raster:



Any idea where to proceed from here?

Also, thanks Steve for pointing me towards the legs - Home Depot doesn't carry them and Lowe's was out of stock, but I found them at ACE Hardware for less than four bucks apiece. I think they're a little narrower than the originals and the brass caps are definitely shorter but they're close enough for me!

[RetroHacker]

That HV static you're hearing is pretty normal on a lot of these old sets. You'll get what you described - static/audio on the speakers, scanning wine, and then a whoosh of static zaps for a second or two, then a picture. It just takes a while for all the tubes to heat up and start working. The static zaps should sound like you've just wiped your hand in front of a running tv set.

If you're getting more than just a quick woosh of static, check to be sure that the anode cap on the tube is clean, and the suction cup is stuck on decently. A dirty, dusty tube can cause some of this. A hissing, frying sound is quite possible here too. Double check that there isn't any crud in the connection to the top caps of the HV rectifier, HV regulator and horizontal output tubes.

If you run the set in a darkened room, you can see where the zaps are coming from.

You're making good progress!

-Ian

[Sandy G]

So close, so close...You'll be enjoying Glorious Lollipop Color in no time !! (grin)

[RetroHacker]

Ah, I see you beat me to it. Looks good. You're making great progress. HV is the first major obstacle.

It looks like you have a full raster, that's a great sign. It's hard to tell, but it looks like your horizontal isn't locking. By twiddleing the vertical hold, you should be able to get the mess to roll top to bottom. But, I don't see a locked horizontal. Are you feeding in a signal - i.e. antenna? You should be able to get a clear snow, with no black lines through it. The picture looks a bit purple - could be a weak green gun, or could be a lot of other things. Don't worry about that right now. Concentrate on getting a clear, stable raster. The color circuits can come later.

What sections have you recapped so far?

-Ian

[classicradio]

The set is being fed from an antenna - just a pair of rabbit ears. Yes the screen is very blue although I see a red line thats maybe collapsed at the bottom of the screen.

I haven't fully "recapped" any sections yet. The thought of depleting my entire radio capacitor selection by replacing the 135 or so capacitors I counted on the schematic is frightening. So far I've replaced the two can capacitors, C122 which is across the primary of the vertical output transformer, C604 in the horiz. osc. circuit across the sine wave coil, and C610 on the cathode of the 6CG7.

This brings up a few questions:

1) What is the chance that any of the disc capacitors are still good in comparison to the failure rates of the paper capacitors? Also can these be replaced by the same 630V metalized poly film caps that I use for the paper caps?

2) Why doesn't the service manual have a parts list? This would be unheard of for larger tube count radio schematics.

3) Is there any way I can adapt my Eico 635 tube tester to check the guns on this color tube? It has the 8 and 12 pin 110 degree sockets but no 14 pin socket. I would hate to get any further with this set only to find that I do have a bad tube.

Thanks!

[classicradio]

Partial Success!!!

Well after realizing that I hooked the VHF antenna to the UHF connector and realizing that the blue connectors weren't even hooked up to the VHF tuner (duh) I decided that I didn't really give the set much of a chance! Here's some pictures in order of my adjusting them - thanks for the tip on playing with the vertical hold - its been years since I've used a tv older than I am.












The following one says Menards, 5%. You can really see how badly the red is skewed here:



The audio comes in loud and clear and sounds great, so I know I should expect a much better picture on this station.




Does anyone have any better suggestions for me now? The green is still nonexistent except in green streaks here and there when the channel starts to roll.

[eberts]

Check the "drive" controls on chasis, check voltage going to green screen, looks like an open resistor.
You need to converge the picture. The blue magnet should be on top, red on the right. Slide the pole magnets up and down till the colors are on top of each other.

[jpdylon]

can you adjust the fine tuning to improve the picture any? Perhaps you're missing video signal?

[bgadow]

Originally Posted by classicradio

1) What is the chance that any of the disc capacitors are still good in comparison to the failure rates of the paper capacitors? Also can these be replaced by the same 630V metalized poly film caps that I use for the paper caps?

I would totally ignore the disc caps. It is highly unlikely that any are bad. Down the road if there is a problem you can look at them.

This does look good! I know it is scary when you first power a monster like this up. This is the part when I would be doing some twiddling of various adjustments to see what improvements could be made. The AGC should be tweaked, for one. The convergence is way out but that isn't unusual.

I'm not familiar with your tester, so I can't say if it can test this tube. I would think any of them from the mid-50s on should be able to, but they might require an adapter that could be hard to find. At this stage the set is working enough that you can get a good idea of how well the crt will perform just by doing the setup, grayscale, etc.

[classicradio]

Well after replacing all 52 of the paper capacitors except the high voltage ones (1600 & 2000V) on the top of the chassis, I powered up the set again.

I now have much improved results:









I am surprised that the VHF section (1st 2 pics) has a much much clearer picture than the UHF section (2nd 2 pics). I am wondering if I have bad resistors somewhere in the tuner, or if my 6EA8 substitutes for 6U8 tubes over most of the chassis are causing problems. Unfortunately in all the tubes I had only one 6U8 was not short.

The green is definitely alive, but the picture is still collapsed on the bottom of the set. I also need to seriously work on the color convergence of the set - but I don't have any instructions for my Philco model 7100 color bar and dot generator, and so far no way of hooking it up to the TV has produced any results. Has anyone used a similar apparatus that knows generally what the procedure is?

I suppose ditching the rabbit ears and borrowing someone's VCR might help troubleshoot this set as well.

Slowly, but surely!

[sampson159]

looking good! its all downhill from here. do some basic set-up adjustments;purity,center convergance,etc and that should get it going. vertical could be resistor between centering and height controls. havent seen rca roundie that didn t need that replaced.keep posting pics!