Hi everyone,
I hope I'm not breaking any unwritten rule by posting my question here as well as the Antique Radio Forum. No disrespect intended to the helpful members there. I'm only hoping to have more eyes look at my problem to help me solve it.
Alright, so here goes. The television had a dry rotted power cord, so I only tested the low voltage power supply after getting a new one and having replaced many resistors as well as all capacitors minus the micas. The power resistors in the bleeder network were replaced, but the candohm checked out fine, so I left it. The secondary transformer's center tap voltage measured at pins 4 and 6 of the removed 5U4G tubes was only 196 volts, when it should have been about 320 volts. I don't have proper voltage at the primary winding. Prior to turning the set on, I have 120 volts at the .01 uF safety caps, the terminal strip that connects the safety caps line to the on/off switch line, and the on/off switch. When I turn the set on the safety caps voltage drops to 62 volts, the terminal strip drops to zero along with the on/off switch. I have 62 volts at the primary winding. I've spryed Deoxit in the on/off switch, and exercised it. Its resistance readings are correct (infinite when off and about zero when on). By the way, there are quite a few caps and resistors that I changed in the volume control circuit attached to the on/off switch. That corner of the set is a jungle of components jammed into a very tight space. Could the problem lie in there? I'd appreciate any help you can give.
Thanks,
Mike

http://www.earlytelevision.org/pdf/rca-8ts30-rider-tv2.pdf

Maybe what I might do is trace from the power to the transformer and if the power branches off to a resistor befor reaching the trans then check it or anything else in between. I would think its the power in to the on- off switch one wire then look for the other power wire where that one goes. Unless maybe you are using an outlet that has a dimmer on it maybe. :scratch2: either way the primary should be 115 or 120 volts unless the transformer is bad. Ok I looked at the schematic, did you check for any output on the secondary? And those caps at the transformer c 183 and c184 don't have anything to do with the power going into the trans, if they were holding back in some way they would explode so that's out. Check the secondary for output. The 62 volts you speak of sounds like half the line voltage.

Any chance you're using a dim bulb tester with too low of wattage bulb, or a Variac set too low? Definitely seems like something is dropping line voltage before it enters your set. Caps and resistors in the set could not do that, unless you've inadvertently wired a component in series with one of the AC lines before the transformers primary.

Are you measuring safety cap voltage and winding voltages to the chassis, perhaps. :scratch2:

jr

As I posted on the ARF, the chances are that it is a bad cord/chassis connector based on the information provided. I would also reflow all associated solder joints.
Best way to get down to the bottom of it is to take a line cord, strip the ends and connect it directly to the power transformer. If that works then connect it across where the safety caps connect to prove the switch. Process of elimination would leave the line cord/connector as the last possibly bad item.

There is nothing to powering this transformer up.
https://i.imgur.com/SCv0nwX.jpg

I'm with Kevin Something is miswired and "added" to the circuit. I wouldn't force ac mains power across the primary leads quite yet. The circuit is too simple. Carefully trace it out and verify the primary leads to the transformer.

With the power switched on and set unplugged, measure across the AC plug. should be 0.6 ohms.

I'm happy to report that the fault was not with the television, but rather my dim bulb tester. All voltages are present and accounted for. Thanks for patiently working with me to find the solution. I'll be back with more problems as they arise. I'm so glad the initial tests are good. I was starting to think I had wasted a lot of time and money on something that would never work. By the way, does anyone have any experience with a company called Amptech Systems, and the work they do repairing detent assemblies for the tuning shafts of early model RCA televisions? Mine doesn't click correctly when channels are changed. It seems like $80 is a reasonable price to pay to have it repaired.

By the way, does anyone have any experience with a company called Amptech Systems, and the work they do repairing detent assemblies for the tuning shafts of early model RCA televisions? Mine doesn't click correctly when channels are changed. It seems like $80 is a reasonable price to pay to have it repaired.

I'm not real familiar with your sets specific tuner, but I'd suggest before going to all the bother and expense of removal and shipping, that you post some close up pictures of the mech which may help us better diagnose what the problem could be. It's possible someone had it apart and left a part out. By removal you're inviting more potential for damage and wiring errors.

Here's some info I found on the web:

http://evilfurnaceman.tripod.com/tvsite/rca-victor-model-8ts30.html

"THE TUNER DETENT ASSEMBLY IS EASILY BROKEN. REPLACEMENTS ARE IMPOSSIBLE TO FIND. WHEN CLEANING THE TUNER IN ONE OF THESE, DO NOT USE CONTACT CLEANER WITH ANY KIND OF LUBRICANT. IT WILL SEND THE SOUND CARRIER INTO OUTER SPACE. I USE COTTON SWABS DIPPED IN ALCOHOL, OR A NON-LUBRICATING CLEANER. ALSO, THIS SET HAS CHANNEL 1."

http://antiqueradios.com/forums/viewtopic.php?f=3&t=10886

"Some old tuners have a springy strip anchored to the tuner shaft. This has a cutout for a ball bearing which clicks into little depressions in the front plate of the tuner. If the spring breaks, the ball falls out and you have no detent - the switch will just glide from channel to channel. If anyone has ever found a repair for this, I'd like to hear about it;"

"I have a fix for the tuner detent problem. I ran into the same problem on a 630TS which I recently restored, which of course uses the same tuner. Luckily, it is fairly easy to dis-assemble the shaft from this particular tuner; I don't have it in front of me at the moment but there are just a few screws accessible from the front around the shaft, which when removed allow the shaft and detent mechanism to be slid out the front. Be careful not to disturb the positions of switch sections when you slide it out!

As was mentioned, the problem is usually caused by a broken spring clip and a missing ball-bearing. I drilled out the rivet holding the old spring clip and fashioned a replacement from a piece of scrap plastic with 3 drilled holes: one for the shaft, one for the rivet (replaced with a small nut and bolt) and one for the ball bearing. I replaced the missing ball bearing with an ordinary brass BB. It works great, though probably not as "crisp" as the original since the plastic is more flexible than the spring steel. Luckily there's plenty of extra room in this tuner to make these mods.<P>I agree that this is an excellent chassis design and well worth the restoration effort - I also have a restored RCA 9PC41 projection TV which as mentioned uses the same circuitry. The picture is amazingly sharp and clear, despite being blown up from a 5" CRT to a 25" diagonal screen. This chassis also has all of the required adjacent-channel traps to get a good picture direcly off of cable."

Hello again,
I've made some progress since my last posting. I'm able to get a distorted image, which makes me very happy believe it or not. I don't have any sound though, and the fine tuning shaft seems to need some attention. I've attached pictures that show that I'm able to pull it out and spin it freely. I'm not sure if this is to be expected, or something to be concerned about. It doesn't seem to do anything. Also, I mentioned in a previous post that the channel selector needs work on the detent assembly. It's missing the ball bearing. I appreciate the advice given so far, but I'm still not sure of a plan of attack. Any other thoughts on how you would take this on?
Thanks,
Mike

The fine tuning shaft connected to the actual fine tuning control via a belt. Your belt probably rotted off..Time for a new belt.

I didn't know there was a belt. Thanks for letting me know. Any idea what I can use for a replacement? I'd love to see a picture of what it looks like. That would probably go a long way in improving my lack of audio.

I didn't know there was a belt. Thanks for letting me know. Any idea what I can use for a replacement? I'd love to see a picture of what it looks like. That would probably go a long way in improving my lack of audio.

Use a string and make a belt install it then take it off and get a rubber O ring but it has to be smaller then the diameter of the string you just made so that you can stretch it on.

The 8TS doesn't use a belt, if I recall right it has the friction drive.

The 8TS doesn't use a belt, if I recall right it has the friction drive.
I could be wrong, but I've had a 8TS30 and a total of 3 630TS's through the years and never heard of a belt on the fine tuning. I've also never had one where the fine tuning did not work and none had any type of belt replaced.

Thanks for the thoughts on this problem. Are you able to tell from my pictures whether or not it is belt driven or friction drive? Any suggestions on how to increase the friction, so it works correctly. Like I said mine just seems to spin freely having no affect. I'm not clear on how it operates and how to test it.

Isn't the plate (green) supposed to be inside the space (red) between the two drive discs?

http://www.videokarma.org/attachment.php?attachmentid=197469&stc=1&d=1532878827 http://www.videokarma.org/attachment.php?attachmentid=197470&stc=1&d=1532878827

That's correct. The green plate should go between the two red discs.

Thank you Wisco Jim and Tom9589. I didn't see that before you pointed it out. I went down and popped it back in. There doesn't seem to be stopping points, so it will fall out again unless something is done. I really appreciate you taking the time to help me.

Thank you Wisco Jim and Tom9589. I didn't see that before you pointed it out. I went down and popped it back in. There doesn't seem to be stopping points, so it will fall out again unless something is done. I really appreciate you taking the time to help me.
That seems like the problem. I believe the fine tuning should have stopping point which keep the flange from coming off the wheel. Those early RCA's usually have a precise "sweet spot" that you will not need to stray far from. Once you set it, the most you'll need to adjust it is a very slight amount.

Thanks, decojoe67. I'm at a standstill until my tubes come in, but am encouraged to hear the fine tuning is so precise once set. My picture is still too far off to notice any improvement when it's adjusted. I'd love to hear some ideas I could use to prevent the flange from falling off the wheel again. Also, I have time to work on the cabinet, which is in pretty good shape. I'd like to improve it though, and preserve the finish by spraying some Mohawk lacquer over it. I'm looking for advice on how best to do that. I don't have much experience, and don't want to mess this up. I've added new control decals.

Hello again,
I've made some progress since my last posting. I'm able to get a distorted image, which makes me very happy believe it or not. I don't have any sound though, and the fine tuning shaft seems to need some attention. I've attached pictures that show that I'm able to pull it out and spin it freely. I'm not sure if this is to be expected, or something to be concerned about. It doesn't seem to do anything. Also, I mentioned in a previous post that the channel selector needs work on the detent assembly. It's missing the ball bearing. I appreciate the advice given so far, but I'm still not sure of a plan of attack. Any other thoughts on how you would take this on?
Thanks,
Mike
Even though you said you don't have sound yet but the picture is there in your first photo , adjust the horizontal hold and the pic should straighten out, it looks like the hold is off just Alittle.

Hello again,
I can't seem to improve this television's picture using the control knobs and the phase control screw. It won't lock on horizontally or vertically, and images appear washed out. The brightness control has stopped responding. The audio is decent, but intermittent. I have to tap on the first audio IF transformer, T-111. I must have made a mistake somewhere along the line, but don't know where the best place to search first would be. I've changed many tubes hoping for an easy fix, but that made no difference. I sure would appreciate any help you could give me.
Thanks,
Mike

Does the Picture control do anything? If not, I think you should trouble shoot that first. The washed out picture and lack of sync could be due to not being able to turn up the picture control.

If you can get the brightness/contrast adjusted to normal levels and it is still rolling look at the sync separator stage.

Thanks for the quick responses. There are two mica caps that I see in the sync separator circuit. They are C145 and C147. These are 270 uF mica caps between V118 the first sync amplifier and V119, the sync separator. I didn't change those, because I thought doing so would then require me to perform a full alignment which is out of my comfort zone. Are those two possible culprits? If so, I'll get rid of them.

Thanks for the quick responses. There are two mica caps that I see in the sync separator circuit. They are C145 and C147. These are 270 uF mica caps between V118 the first sync amplifier and V119, the sync separator. I didn't change those, because I thought doing so would then require me to perform a full alignment which is out of my comfort zone. Are those two possible culprits? If so, I'll get rid of them.

First thing is first, make sure you can get correct contrast.
The sync separator depends on video amplitude being within a correct range. If the video level is too low or too high then even a properly operational sync separator will not provide the right output (garbage in garbage out).

The sync separator has no relation to alignment. (And if you chopped off all the IF systems and injected audio and video you would still need the sync separator stage to allow H and V to sync.)
If the video level into the synch sep is correct per-original design, then yes those capacitors could be a problem...As could any resistors in the circuit or the tube.

General roll troubleshooting advice: in a set where all else works correctly if both H and V roll (and user controls allow you to adjust which direction it rolls) then the issue is almost always in the sync sep stage.
If only one axis rolls (direction controllable) then the issue is probably in the axis rolling though could be a separator issue if the other axis has weak sync with a very small lock in range. If contrast is excessive or insufficient at normal screen brightness (assuming good CRT) and both axes roll the problem is likely to be video level. If an axis rolls, but you can only get it to roll one way that axis has problems/is operating off frequency. If only one axis rolls (other has a solid lock) then that axis or it's connection to the sync sep is at fault.

This is a case where it is best to find the problem through diagnostics rather than throw parts at the wall to see if they stick.

Also do not rule out a bad connection on the tube sockets , wiggle tubes if possible to see of it makes any changes

Thanks for the quick responses. There are two mica caps that I see in the sync separator circuit. They are C145 and C147. These are 270 uF mica caps between V118 the first sync amplifier and V119, the sync separator. I didn't change those, because I thought doing so would then require me to perform a full alignment which is out of my comfort zone. Are those two possible culprits? If so, I'll get rid of them.

Please don't take this wrong, but you did not answer the question about the picture control that was trying to help you, and instead asked about some parts in the sync separator. It's not possible for others to help diagnose at a distance if you do not answer questions that are trying to isolate the symptoms.

You're right, old_tv_nut, I did do that, didn't I. I guess I'm looking for a quick solution to a problem that requires deliberate troubleshooting. Sorry about that. It's not easy trying to help someone from a distance, and I appreciate the effort. Now to answer your question. The picture control does seem to work correctly. It's the brightness that had been working, but stopped. The syncing problems have been consistently present.
Also, I did replace and wiggle the tubes, Kramden66. That doesn't have any effect.
Thanks for the troubleshooting advice, Electronic M. The controls do affect the direction of the vertical and horizontal lines. Can you tell me if I would need an oscilloscope to check the video levels, or can it be done using a multimeter? I've got one, but it's been a while since I've used it.

OK now - if the picture control goes through a range of weak picture to too strong, and there is no change to the sync, then it is likely the sync separator circuit that is the problem.

An oscilloscope would be helpful if you have a reference telling you what amplitude the waveforms should be. If not, you would just be guessing. I can only make this general statement, but maybe someone else here can give you a reference.

It sounds like you need to know the normal signals at the input to the sync separator and in various parts of the sync separator. Before you do that, though, a check of DC voltages in the sync separator circuit may point to something.

Edit: I see Riders has waveforms, so there you go.

Here are the latest developments. It turns out that I already had replaced those mica caps, so that rules that out. I had the brightness control working correctly for about five minutes after turning the set on while on its side this morning. Then I lost it. I thought I'd let everything cool down, and try it again but no luck. Regarding voltage readings on the sync separator tube there are differing results expected on the Sam's Photofact and the Rider's voltage charts. On the Sam's chart pin 4 should read -2.6 vdc. On the Rider's chart pin 4 should read -5.2 with the picture control set to minimum, and -9 volts with it set to maximum and depending on the noise level. I'm reading -4.6 volts and the picture control is not changing it. I'll continue trying to find a mistake I may have made along the way. Thanks for the help.

Sometimes if one of the pins on the CRT is not making proper contact you won't be able to control brightness , that would explain the sync but maybe you have two issues not related , you could wiggle the the CRT connector to see if that's the brightness issue

Hello all,
Sorry for the delay in responding, but I grew very frustrated at my inability to solve the problems with this set, and had to walk away for a while. I wish I had half the ability of many on this site. Well anyway, I'm back at it. I've taken pictures of signals at various points, and need your help in determining where to go from here. You'll find pictures of the signals I'm referring to in the link that follows. The brightness and contrast are working, but most of the time I don't have horizontal or vertical lock. I hope you're able to help me out of this rut.

Photo #1: Video signal to first video amp. Scope is on the 2 volt scale.
Photo #2: Output of first video amp. Scope is on 2 volt scale, probe at X10.
Photo #3: Input to kinescope. Junction of C141, R148, and green lead to kinescope. Scope is on 5 volt scale.
Photo #4: Cathode of D-C Restorer. Scope is on 5 volt scale.
Photo #5: Plate of D-C Restorer. Pin 2 of V114-B. Scope on 5 volt scale.

fine.http://www.earlytelevision.org/pdf/rca_8ts30_rider_tv2.pdf

It looks like the video amplitude at the kinescope is about right (schematic says 38 v p-p, If I'm reading the scope scale right you have about 25 v, but that should vary with contrast setting). I think you should measure the signals in the sync separator. Schematic says input to sync sep, pin 4 of V119 6SH7 should be 35 v pp, output (Pin 8) should be 75 v p-p. Check the output first, if it's not good, check the input. If it's not good, check the signals around the 1st sync amplifier.

I'll check those signals soon. I chose to focus on the areas before the synch circuitry, because the signal does not consistently look like it does in the pictures. The signals vary in voltage and noise levels quite a bit.

I'll check those signals soon. I chose to focus on the areas before the synch circuitry, because the signal does not consistently look like it does in the pictures. The signals vary in voltage and noise levels quite a bit.
If you are feeding it a live TV signal and not a test pattern the signal will vary.
The Synch pulses should have a constant tallness and never be swamped by noise...Changes in areas of the signal other than the synch pulse typically are not noise (unless your screen gets snowy with signal sometimes) but rather changes in video content. If you want to make sure the signal and the circuits amplifying it are stable feed the set a test pattern from a test pattern generator or feed it signal from a DVD player that is paused on a frame that gives a nice waveform.

Interesting. I don't have a test pattern generator. Can I continue using the VCR hooked up now, or do I have to use a DVD player?

Yes, if you can pause a DVD on a frame with a blank grey screen that would result in the least confusing scope trace because the picture signal is constant. That may cover up a problem however if the picture information is effecting the sync, but it is a good start. Next best would be a scene with just two levels of grey, maybe the credits on a movie.

VCRs (if playing tape) would be the least recommended signal source for troubleshooting...Especially sync troubleshooting.

VCRs record the complete signal on tape and play it back...As such the most minute lack of precision in the mechanical systems results in sync errors in the VCRs output. Sets made before 1970 were not made with VCRs in mind and will have a harder time correctly syncing to tape than say an 80's TV set, but even the newer sets will show some errors if the signal is bad enough.

Use a DVD player, OTA DTV/cable/sat converter or test pattern generator for troubleshooting.

If your DVD player lacks RF output then you can plug it's A/V output into the VCRs A/V input, tune the VCR to it's A/V input and use the VCR to RF modulate the DVD signal. The VCR should not cause sync issues as long as you do not use it to play videotape.

Hello again. I used a DVD player, and ran it through my VCR to get these signals. Sorry about the extra trace in the pictures. I couldn't figure out how to make it disappear. I appreciate all the help so far, and could use some feedback as to where to go from here.

Photos #1 and 2: Output of first sync amplifier. About 60 volts. Probe X10, Scope X2 scale.

Photo #3: Input to sync separator. About 25 volts, which would be low. Should be 35 volts. Probe X1, Scope X5 scale.

Photo #4: Output of sync separator. About 80 volts. Probe X10, Scope X5.

Can you explain why you have two waveforms for the output of the first sync amplifier? H and V rate? Neither one looks very much like the waveforms on the schematic. The first one, that appears to be H rate, appears to be inverted compared to the schematic.

Picture 3, input to sync separator, seems to have a lot of video. (On the schematic, it shows mostly sync pulses with a little video leaking through.) As a result of the excess video, the output of the sync separator has a lot of video also - it should be purely sync pulses.

I would start by checking the first sync amplifier. Check DC voltages. Check component values. Do you have a known good tube to substitute?

I must have been rushing. I hope these pictures are more helpful. I'll follow your advice and look for the problem in the sync amplifier section. I'll look for another tube. I bought a replacement for that already, but didn't check it on my tube tester. I'll do that today. Here are new pictures taken today.

Photo #1: Plate of D-C Restorer. It's 15 volts, and should be 9 volts.

Photo #2: Output of first sync. amp. It's 75 volts, and should be 35 volts.

Photo #3: Input to sync separator. It's 32 volts, and should be 35 volts.

Photo #4: Output of sync separator. It's 90 volts, and should be 75 volts.

By the way, I enjoyed looking at your webpage, especially the World's Fair section.

Did you download the Rider manual? In case I wasn't clear, that's the one with the waveforms I have been referring to.

When you say output of first sync amp is 75 volts, is that 75 DC or peak to peak?
Schematic says the plate (pin 8) DC should be between 163 and 185 v dc depending on picture setting. Peak to peak should be 40 volts pp horizontal or 58v pp including the vertical pulse.

I don't see where you got "should be 35." Is that a typo from the input to the sync separator (which should be 35)?

You're right. I misread that part about should be 35 volts. I'm getting 75 volts peak to peak, and yes, it's the Rider's Manual. I tested my recently purchased 6SK7 tube, and it was barely good. The original was a little better, so I popped it in. The stability has improved to the point where the horizontal roll can be stopped for a longer period of time. I still have a slow and steady vertical roll though. Maybe I ought to buy another tube.