View Full Version : I'm getting a SC500 4 tube hybrid!


TUD1
01-16-2017, 06:41 PM
Just saw this set on Craigslist. Called the seller, and I'm going to pick it up Saturday. It's 4 hours away from me. When I saw it, I could not believe my eyes. I immediately got on the horn, and contacted the seller. I absolutely cannot wait to go get it.

Electronic M
01-16-2017, 07:42 PM
You lucky dog!

Only 4 tube hybrid I've ever found is just a rusty chassis.

TUD1
01-16-2017, 08:19 PM
Yep! I'm still in shock! The TV Gods must be shining down upon me. I already know exactly where it's going to go, too. On top of my 1967 RCA CTC-25 Beauchamp that I'll be getting next month. It'll be a nice display.

Adam
01-16-2017, 08:21 PM
That's a great find! I've been looking for one of those for years.

Captainclock
01-16-2017, 09:19 PM
I take it its a remote control set? And I'm guessing that by the fact that its got 2 SC500 remotes with it.

TUD1
01-16-2017, 10:01 PM
Well that, and it says Space Command 500 on the door.

Here is a picture that Doug posted years ago of his set that is identical.

Captainclock
01-17-2017, 11:18 PM
Well that, and it says Space Command 500 on the door.

Here is a picture that Doug posted years ago of his set that is identical.

I actually have a 1960s vintage Philco Townhouse TV, which is a B & W set that needs a little work done to it, anyways apparently that TV could of been remotely controlled because it has a knock-out panel on the cover on the back that says "remote control" on it.

TUD1
01-18-2017, 08:56 AM
A lot of TV's in the 60's had the option of being remote. In the 60's, RCA did some weird stuff with their remote sets. Sometimes, only a certain cabinet style, or even finish would be available with remote, regardless of what chassis the set contained.

Captainclock
01-18-2017, 12:39 PM
A lot of TV's in the 60's had the option of being remote. In the 60's, RCA did some weird stuff with their remote sets. Sometimes, only a certain cabinet style, or even finish would be available with remote, regardless of what chassis the set contained.

Interesting. I would love to find my Philco Townhouse TV a new home with someone who could better restore the TV than I can because its got issues with it that I can't really repair myself because I've never done those kinds of repairs before, like the fact that the orginal picture tube in it has failing Aquadag and I don't have any experience with redoing the aquadag coating on a picture tube and also the vertical is messed up on it because instead of running at 60 Hz. its running at 30 Hz. which is causing a doubled picture.

BigDavesTV
01-18-2017, 12:53 PM
Congratulations, Universal Dave! Great set and remote, to boot! Remote version of this is much harder to find than the non-remote, and I finally got a nice non-remote Zenith 19" Hybrid, last year! One of my favorites, as for Zenith.

Captainclock
01-18-2017, 07:22 PM
You know Dave, even though your siggy says you're looking for a Zenith Space Command 400 or 600 Color TV, this Space Command 500 TV might just be good enough to fulfill your siggy's wishlist because not only is it in between those two models but also seeing as the SC400 and SC600s are extremely rare TVs you might just have to say that this SC500 TV is a Nice compromise set and also pretty much has fulfilled your need for an early Space Command remote controlled Color TV without too much looking around. :thmbsp: :yes:

TUD1
01-18-2017, 08:14 PM
I suppose. But I still need a Space Command color console.

Adam
01-18-2017, 08:19 PM
I think the SC500s and SC100s might be the rarest of all the Zenith remote sets (maybe except for the flashmatic). I've had 21 Zeniths with ultrasonic remotes, and not a single SC500 and only one SC100.

If there was a way to transport them, I'd trade you a '67 Zenith SC600 25" color console for this set.

Jon A.
01-18-2017, 08:31 PM
It seems the 1973 flats are far more common than the 1972 flats, so my guess is that it's the same with the four-tubers. I've seen many SC500 remotes on eBay, but very few were of the 1972 design.

I'm not even sure if the 19" sets were available with SC600.

TUD1
01-18-2017, 08:39 PM
I think the SC500s and SC100s might be the rarest of all the Zenith remote sets (maybe except for the flashmatic). I've had 21 Zeniths with ultrasonic remotes, and not a single SC500 and only one SC100.

If there was a way to transport them, I'd trade you a '67 Zenith SC600 25" color console for this set.

Please feel free to post a picture of said console so I can see what I'm missing out on.

TUD1
01-18-2017, 08:41 PM
It seems the 1973 flats are far more common than the 1972 flats, so my guess is that it's the same with the four-tubers. I've seen many SC500 remotes on eBay, but very few were of the 1972 design.

I'm not even sure if the 19" sets were available with SC600.

You mean 1972 flats like this one?

Adam
01-18-2017, 09:15 PM
Here it is. I have two SC600 consoles with the 23XC36 chassis, so I wouldn't mind trading one of them. I'd probably throw in that '79 Sears console sitting in front of it too. (But otherwise I'm not looking to sell that Zenith console at all)

TUD1
01-18-2017, 09:42 PM
That's a nice set, Adam. If I weren't so far away, that would be a good trade.

Jon A.
01-19-2017, 04:43 AM
You mean 1972 flats like this one?
Yup, and consoles.

DavGoodlin
01-19-2017, 05:09 PM
What is the chassis number on that hybrid SC500? 19DC12 or similar uber-workhorse, right? Tom's right you are a lucky dog finding that!

TUD1
01-19-2017, 06:30 PM
I think it's a 19CC19, but I don't know yet. As soon as I get it, expect many photos.

DavGoodlin
01-20-2017, 02:48 PM
If the flatty 25DC56/EC58 was the best large-screen, the 4-tube hybrids are certainly the best of the 19 inchers.

I saw many later 19" vertical chassis CCII sets but these might just be better.

TUD1
01-20-2017, 04:35 PM
I have a 1976 Zenith 19" CCII, and I'm ready for it to go. I have no use for it at this point. Anybody want it?

Captainclock
01-20-2017, 09:11 PM
I have a 1976 Zenith 19" CCII, and I'm ready for it to go. I have no use for it at this point. Anybody want it?

I would be interested in it if it werent for the fact that you live all the way down in Alabama and I live all the way up here in the Great Hoosier State of Indiana, which makes transporting the TV a problem.

TUD1
01-20-2017, 09:31 PM
I just talked to the seller of the hybrid, and I'm definitely going to get it tomorrow. Driving 5 hours one way.

TUD1
01-21-2017, 06:02 AM
Just woke up. About to go 510 miles to get this set. Updates to come.

TUD1
01-21-2017, 01:55 PM
Mine!!!!! Unfortunately, the vertical must have collapsed at some point and caused a line to be burned in the phosphor.

Captainclock
01-21-2017, 08:50 PM
Mine!!!!! Unfortunately, the vertical must have collapsed at some point and caused a line to be burned in the phosphor.

Well that sucks... Is it somethings that's too terribly noticeable? Like do you see the line that's burned into the picture tube when the TV is on? If not then I wouldn't worry too much about it seeing as the picture tube that that tv takes is probably going to be harder to find that the TV itself was.

TUD1
01-21-2017, 09:24 PM
After powering it up and analyzing it, it has way more problems than I anticipated. The remote control chassis doesn't work at all, and yes I put it in "auto" mode. The focus is bad, the UHF dial is way off, the vertical won't lock most of the time, and it's EXTREMELY dirty inside. I'll take it apart tomorrow and CLEAN it.

TUD1
01-21-2017, 11:38 PM
Just got through CLEANING the set. It's amazing what a good cleaning can do to the performance. Cleaned the CRT anode, tube sockets, transistor sockets, control pots, tuner, and modules. The vertical jitter and high voltage arcing have been eliminated. Also cleaned the master on off switch as it was kind of flakey. Unfortunately, the remote chassis is still not working. Cleaned the wire going from the transducer to the remote chassis, but that didn't help. I'll have to seek professional repair.

SpaceAge
01-22-2017, 01:05 AM
510 miles! I commend your dedication. What state was it in?

Electronic M
01-22-2017, 02:18 AM
Got a scope? Remote issues are easy to fix with a scope, diddle stick, and the remote.

Most remotes consist of a few stages (often 2-4) of wide is band amplification, that then feeds tuned filters and relay driver amps for each function. I usually put a scope on the point at which the wide band amp splits off into the filters. If I get signal when pushing buttons on the remote then the wide band amp works and the filters need to be tuned or the rely drivers have issues. If I don't get a signal I scope the ultrasonic mike input to the chassis and if I get signal there then I troubleshoot the wide band amp. Let me see if I have a schematic for something similar...Zenith SC RX's (and most ultrasonic chassis) were all very similar just add or delete a stage between models.

Jon A.
01-22-2017, 07:13 AM
That remote switch is an odd sight, looks like something has to be removed for it to move. Those things often cause trouble. Then again, mine sometimes wouldn't respond until the clicker was held right up to the mic.

TUD1
01-22-2017, 10:29 AM
The big filter cap is failing. It's gets real warm, and the picture will start tearing. After about 5 minutes, big white bars start running up the screen. But until all that starts up, it's not half bad.

drh4683
02-01-2017, 06:41 PM
Greetings & congratulations on an excellent find! I don't think I've ever seen a Zenith CRT with a line etched into it from loss of vertical sweep. Someone must have cranked the G2 controls and left it like that for a while for that to happen. Certainly replace that filter cap if it's warm to the touch. I can almost guarantee that the reason the space command chassis is dead is because of a particular electrolytic capacitor in the power supply of the space command chassis itself that has failed. If I remember correctly, the Space Command 500 circuitry is mounted on a PC board within that metal sub-chassis and somewhere toward the middle of the board is the very small radial 'lytic with a value of about 10uf @ 3 volts which is the suspected culprit. I've had a number of these sets over the years and with every one of them, that cap was the reason the space command didn't work. The last time I had one apart to repair was 10 years ago, so thats why my memory is a little foggy. The other caps within the space command chassis are probably OK as I think they are a different brand that held up better. When that 10uf cap fails (due to high ESR) it's basically an open circuit and you lose collector voltage on all the transistors which is why everything ends up being dead. You shouldn't need to align anything after replacing it. It's a nice quick and easy repair.

TUD1
02-01-2017, 08:22 PM
Good to hear from you Doug, and thanks for the input. I'll certainly look in to replacing that capacitor too.

wa2ise
02-03-2017, 05:45 PM
FWIW, your two pictures of the chassis can create a 3D picture.
http://videokarma.org/attachment.php?attachmentid=193627&stc=1&d=1486161768
Cross eye mode, make your left eye shift on the right portion of the image, and right eye on the left.

Jon A.
02-04-2017, 03:52 PM
FWIW, your two pictures of the chassis can create a 3D picture.

Cross eye mode, make your left eye shift on the right portion of the image, and right eye on the left.
I can't cross my eyes, but good one Bob! :thmbsp:

walterbeers
02-04-2017, 04:06 PM
Take it from someone who used to repair these models, they are great sets and produced good pictures. I owned one myself and watched it for years. Only problem I had was when I hooked a VCR to it, the top of the picture would flutter and bend on certain tapes. There was a modification that could be made to make the horizontal AFC more stable, I tried it, and it made it better but not perfect. I no longer know or remember what I had to do to the circuit to correct the problem. I believe it has a 6U10 as the horizontal osc and AFC. The tubes were always a problem and it was best if they were bad to replace all four of them at the same time.

TUD1
04-11-2017, 12:45 AM
Went to watch this set today, and I was pretty dissapointed with the image I got. Very blurry and out of focus. Took the set to my atelier, tweaked HV to the 26KV that it calls for, adjusted G2's, and adjusted focus. The NTSC test image looked amazingly vivid and sharp, but the image from the Directv box sucks. Even after adjusting.

dishdude
04-11-2017, 12:53 AM
Went to watch this set today, and I was pretty dissapointed with the image I got. Very blurry and out of focus. Took the set to my atelier, tweaked HV to the 26KV that it calls for, adjusted G2's, and adjusted focus. The NTSC test image looked amazingly vivid and sharp, but the image from the Directv box sucks. Even after adjusting.

Weird. I'd say the CRT looks good, could this be an issue in the tuner? It looks like there is a lot of noise in the picture.

TUD1
04-11-2017, 12:58 AM
I plugged the coax from the main VCR straight into the VHF tuner, and I got an absoluty disgusting picture. Extremely distorted, the color is WAY out of whack, and the focus has taken a dump. I don't know what's happened to this TV. It's unwatchable like this.

Findm-Keepm
04-11-2017, 01:16 AM
I plugged the coax from the main VCR straight into the VHF tuner, and I got an absoluty disgusting picture. Extremely distorted, the color is WAY out of whack, and the focus has taken a dump. I don't know what's happened to this TV. It's unwatchable like this.

What is the Cable box set for .....480I or 480P output? I had an issue with a friend's 21" B/W set with the "fuzzies" - changing the output of the Motorola cable box solved the problems.

What gave it away was the kid in the room - his Wii has identical settings, and he knew what the setting should've been....RF output, but different settings available...

Findm-Keepm
04-11-2017, 01:23 AM
You know, 3 pages of this thread, and not one mention of the chassis number. IMPORTANT if the search function means anything to anyone, or if (like me) you want to pull the service data and symptom/cure chart.

USELESS without a chassis or model number. BTW, the search function can only search text - don't rely on pictures to tell the model and chassis info.

Off to easier threads....

http://www.videokarma.org/showpost.php?p=3152064&postcount=1

at the top of every subforum for a reason.

zeno
04-11-2017, 08:06 AM
Yup that picture sucks but it has what it needs.
Try the AGC delay control. Turn til it gets snowy
then go the other way til it JUST clears up. Turning down the
sharpness ( on rear) will also help. The symptoms add up. If the box is overloading the set putting it right into the 75 ohms at tuner will make it
worse. The box has another challenge for the set. Very high contrast
that just wasnt around then. Without a comb filter the small
the small lettering will be terrible. If the set were tired it
would actually look better.

BTW also check the RF cable & matching transformer, they are
often crap now.

73 Zeno:smoke:
LFOD !

TUD1
04-11-2017, 08:33 AM
Used the exact same matching transformer and cable on my CTC-11 and it looked fine. All my other TV's look fine this way too. Model C6030-13, Chassis 19CC19C.

Electronic M
04-11-2017, 10:03 AM
Given the jaggedness of the edge it looks to be on the edge of loosing sync...It all looks like symptoms of the AGC being set for too much gain and possibly mis-adjusted fine tuning.

If it were perfectly synced and fine tuning were set for optimal detail I'd ask you to put a meter on the focus line and run the control through it's range....If your set uses a focus divider off the 25KV HV line like my earlier 12B13C52 those will sometimes drift a bit...I solved mine by adding resistance on the correct side of the focus pot to bring it back into range...Drifted back out twice in a ~year then stabilized long term after the last adjustment.

TUD1
04-11-2017, 10:57 AM
I'll try adjusting the AGC tonite.

TUD1
04-11-2017, 04:58 PM
I turned the set on to adjust the AGC, and this time there was no raster at all. Just audio and a black screen with absolutely nothing on channel 3 and 16 from my modulator. Tuned to an unused channel, and there is nice brite snow. Turned on another TV to make sure there was input signal. I watched the set last night for a while (with a sucky picture), and it's not doing a goshdarn thing today.

TUD1
04-11-2017, 05:20 PM
Update - Found my small screwdriver and adjusted AGC, and got my video back. Somehow it was WAY off. (???) However, I'm still having a problem with the vertical. I don't know if this is somehow related to the blanking interval? The horizontal lines are nice and crisp, but vertical lines are very noisy.

Electronic M
04-11-2017, 05:30 PM
That looks like the color circuitry being driven off the monochrome bars (something you'll see on fine text or sometimes with miss-adjusted fine tuning). Some of my sets barely do it some others are terrible. I wish I knew exactly what causes it and how to fix it.

TUD1
04-11-2017, 05:51 PM
This thing is just way screwed up. The NTSC test pattern looks *acceptable* but actual programming looks like pure trash. I've adjusted AGC, and I'm out of ideas. As you can see, the lines are not well defined at all, and it just looks very dull. Could a module be making a bad connection??? The test pattern looked WAY more crisp in my atelier last night.

Electronic M
04-11-2017, 08:01 PM
Adjust the AGC with it on the cable box. AGC setting can be wrong for some sources if adjusted using others.

TUD1
04-11-2017, 08:18 PM
Did that. Made no difference.

old_coot88
04-11-2017, 09:22 PM
Possibly a plug-in transistor that's poorly seated.

TUD1
04-11-2017, 11:57 PM
Took out every transistor, module, and tube one by one, and squirted Deoxit into every socket. After that, I got a very nice, sharp, vivid picture with well defined lines on the NTSC generator ONLY. After about ten minutes, the definition of the NTSC color bars went away, and it was just like it was earlier today with very poor definition. I was able to get a somewhat watchable picture on UHF 16, but VHF 3 still has contrast through the roof. AGC does nothing to compensate for too much contrast. Thinking either a bad electrolytic cap or transistor.

Jon A.
04-12-2017, 01:17 AM
Do you have a lot of electrical wires laying around? Try re-routing and bundling them, and unplugging any unnecessary ones. I've had electrical wiring cause weird intermittent problems that I spent weeks chasing. I moved one for an unrelated issue and presto, problem gone.

zeno
04-12-2017, 09:31 AM
There may be 2 AGC controls but I just dont remember.
One is RF AGC or AGC delay. Its the one I mentioned & only
changes the RF gain.
The other is for IF gain, look for it. It may not have both.
The IF strip also has a C-2 adjust pot. Its basically a video
output level.
You can try that too but since the set worked OK for a while
I am leaning tward small 'lytics now.

73 Zeno:smoke:
LFOD !

andy
04-12-2017, 11:15 AM
I'd also go over the modules (and chassis) looking for bad solder connections. In the 70's Zenith had some of the worst soldering I've ever seen. They were new to circuit boards and it took them a while to catch up on soldering. Heat, dirt and age only make things worse. I've even seen sets where one or two of the chassis terminal cones weren't soldered at all.

Failing that, maybe someone here has some spare modules you can try. I'd start with the IF and luma boards.

Have you made any voltage measurements? Comparing things like the tuner's AGC voltage to the manual might reveal something. Sometimes the failure of one power supply voltage can cause all kinds of confusing symptoms. An oscilloscope might also be helpful in this case.

Electronic M
04-12-2017, 11:27 AM
+1 My 12B13C52 has only one module for color demod, color was intermittent (and eventually gray scale was shifting along with poking of the module). I re-flowed the lead on the the chassis contacts and the traces on the module and color has been rock solid since.

If you don't have the schematic for your set I probably do, and can take some pictures of the important areas.