RCA 630TS scored

[bandersen]

I'm planning on using some wood glue.

[bigaudioal]

I was wondering what type of glue to use. Know some cements can be damaging to some materials - especially vintage stuff. THANKS!

[bandersen]

I've never actually glued one of those coils back together before, but I figure wood glue will work well on that material without harming it.

I'm just about done down in this cramped corner. The original 0.005 mfd cap across the audio output transformer had been replaced with a 0.01 mfd.
I put it back to 0.005 mfd but didn't have any more nice yellow Aerovox caps to restuff.

[bandersen]

I'm finally finished with the recapping!


Next came testing all the tubes. I found quite a few that were weak or had shorts and the 1B3 HV rectifier had an open filament.

I also found two 6BC5s and a 6AU6 in place of 6AG5s. Maybe those are valid subs? I'm not sure so replaced them.


I'm going to go through the resistance test chart to double check my work then try powering it up.

[bandersen]

First power up was a mixed bag.

The good news - nothing blew up, the voltages seem reasonable and I am able to hear our LP VHF channel 6

Bad news - HV very weak at around 2 KV so no chance of a raster. Drive control had no effect

Odd news - I'm receiving some FM radio stations loud and clear on VHF 2 and 3

[Geist]

Hi Bob;
I have the same thing, because, of the Sound being on a different set of IF circuits than the video, the sound when it is out of alignment, can pick up some of the FM stations.. In fact, when I first powered my set up, that was How I know I had B+ was that I had picked up a local FM station.. As, I didn't have any picture either.. but, mine was mostly all of the adjustments all out of wack.. But, I do remember a time when I had low HV at about the same as you 2KV, I don't remember though what it was.. I think largely adjustments..
THANK YOU Marty

[bandersen]

There's not much to adjust in the horizontal section. All the resistance and voltage readings are within spec. I'll try swapping out some tubes then fire up a scope and check waveforms. I can the the three or four mica caps in that area too.

[wa2ise]

Originally Posted by bandersen

Odd news - I'm receiving some FM radio stations loud and clear on VHF 2 and 3

You're likely picking up an "image". As the IF in your set is likely around 22MHz, and the local oscillator being higher than the desired reception frequency, if the FM radio station is strong enough, and located 44MHz higher than channels 2 or 3, the FM station will be heard.

[bandersen]

I finally caught the station ID and it's 107.9 FM which is a very strong station. Subtracting 42.5 (21.25 MHz audio IF carrier) results in 65.4 or almost the 65.75 audio carrier of channel 3. Thanks for solving that mystery

The waveforms on the cathode of the HOT and damper are dead on both in frequency, shape and amplitude.


So even though I had previously tested the flyback, etc. inside the HV cage, I decided to take another look. Right away I noticed this mica cap between lugs #1 and #4 which does not appear on the schematic.


I compared it to another 630TS chassis and there's no mica cap here but a paper cap has been added. Hmm, I think I'll remove that mica cap and recheck everything.

[bandersen]

Removing the mica cap had no obvious effect so I tried replacing the HV cap. All I had on hand was 1000pF rather than 500pF like the original. That seemed to help a little and I'm up to 5.5 kV now.


I figure that should be enough to see some glow on the CRT. Then I remembered that the ion trap electromagnet would mess up these test CRTs and removed it from the neck.


Still nothing until I rotated the focus control fully CCW. Finally, a trace!


Swapping out the 6J5 vertical oscillator tube got me some height.


Finally, I feed in a signal and after a lot of tweaking got stable image and decent sound

[Geist]

Hi All;
Bob, I Knew You could do it.. Congratulations..
THANK YOU Marty

[bandersen]

Thanks, but I haven't really fixed it yet, HV is only half of what it should be and FM radio reception is overpowering on channels 2-4.

I tested the mica caps in the horizontal circuits and they're fine. I also replaced the 1 Meg and 3.3 ohm resistor under the HV socket. No improvement. That pretty much just leaves the flyback.


When I first got the set, I tested the flyback using an EICO 944 and Sencore VA-62. I got odd readings on both indicating there might be an issue. However, I got identical readings with another 630TS fly and I figured the odds of them both failing in the same way were unlikely. Also, since I do get horizontal deflection on the CRT it seems to me the fly must be OK

[Geist]

Hi All;
Bob, Do You have a B&K 1077 or something similiar ?? With the B&K unit, you can both Test and insert Signals from the Picture Tube back.. As well as test your Horizontal Section.. Also, since you mentioned your Cathode on your HOT, You should look arround there to see If you have it wired up correctly, just a thought..
THANK YOU Marty

Another great tv coming back to life in your skilled hands!

This is kinda like watching a suspense movie...you know it's going to turn out good in the end, but it's exciting to watch as it goes along.

[bandersen]

Originally Posted by Geist

Hi All;
Bob, Do You have a B&K 1077 or something similiar ?? With the B&K unit, you can both Test and insert Signals from the Picture Tube back.. As well as test your Horizontal Section.. Also, since you mentioned your Cathode on your HOT, You should look arround there to see If you have it wired up correctly, just a thought..
THANK YOU Marty

Yes, I have a 1077 and VA62. All the resistance, voltage and waveforms match the service info within 20% or so.

Originally Posted by egrand

Another great tv coming back to life in your skilled hands!

This is kinda like watching a suspense movie...you know it's going to turn out good in the end, but it's exciting to watch as it goes along.

Thanks. I must admit this was one of my least favorite sets to recap but now that it's coming back to life I'm liking it more and more

I think I might be on to something regarding the flyback. I dug up a crusty old fly from an Admiral 30A1 which crosses to a Thordarson FLY-1 same as the RCA.


I cleaned it up and did a ringing test with a VA62 and got 12. The manual says 10 or above is good. The best I can get with the RCA is only 3 Perhaps that has something to do with why the original 1B3 filament was burned out.

The resistance readings are slightly different, but they are physically identical. Also the 30A1 horizontal circuitry is nearly identical to the RCA so I'm pretty sure it's a legit substitute. One way to find out for sure