Crosley 348CP "Swing-A-View" Restoration
 

I have been working on a Crosley 348CP television for a while now. This set is called the "Swing-A-View" because of the interesting way the CRT pivots out of view when not needed and out when you are watching the set. It's a really cool set and I've not seen many others out there. I am a real sucker for large console sets so this one really caught my eye. I had previously posted two threads about it on VK. Here is the thread explaining how I found it along with three other giants http://videokarma.org/showthread.php?t=267334. And here is a thread where I asked for help with direct video injection for it http://videokarma.org/showthread.php?t=268178. I thought I'd make one thread for the remainder to share the process and more importantly to ask all of you to help push me over the top with this one. I have been terribly unmotivated lately and so tired after working all day, then coming home and dealing with two small children. At the end of the day when they are tucked into bed, the house is clean, and I've answered work email for the day I just want to sit in front of a modern TV and have a drink before going to bed :sigh:. So I'm hoping all of you can give me both the technical help and social encouragement I need to finish this beauty.

The cabinet was in fair condition and needed the help of a pro. I shipped it off to a local cabinet guy in the Pittsburgh area. He has since finished, but I've not been able to pick it up yet. Here are some before shots.

http://i1075.photobucket.com/albums/...psenwnt5k3.jpg

http://i1075.photobucket.com/albums/...psnevknsgj.jpg

http://i1075.photobucket.com/albums/...psripdcr5r.jpg

http://i1075.photobucket.com/albums/...psadaxahks.jpg

http://i1075.photobucket.com/albums/...psymy3m4no.jpg

Not surprised about going the direct video route. This might be the one set (postwar anyway) that is simply unrestorable to original operation.

I enjoyed seeing this set. It has proven to be a rare one. I would say about as rare as some pre-wars. The uniqueness of it certainly makes it worth the effort to return it back to it's former glory. Good luck!

This set has three seperate chassis. The "main" chassis sits on the bottom of the cabinet and houses the tuner, video and audio IF, and the deflection circuits. The "vision" chassis lives inside the swivel box at the top of the cabinet. It houses the CRT and video circuits. Then there is a radio chassis that houses the radio as well as some of the controls for the TV.

Radio chassis:

http://i1075.photobucket.com/albums/...psqh4av0ve.jpg

Top of the vision chassis with 10FP4 CRT:

http://i1075.photobucket.com/albums/...ps3vyv6agy.jpg

Main chassis:

http://i1075.photobucket.com/albums/...pselveomfz.jpg


I am about 85% of the way there with this one, I just need a gentle push to get it finished. I have recapped all three chassis and I'm down to just a few issues left to resolve.

1- The focus control is right up to the end of its adjustment in order to get a focused picture. I'm not sure where the CRT neck will fit in the focus coil when it's in the cabinet so it might not be enough adjustment.

2- The horizontal centering does not work.

3- There is an intermediate loud crackle or distortion that happens after the volume control.

4- There is an odd "zipper" interference in the video. You can see that interference here https://youtu.be/zgcznUOokvw.

I don't know which problem to tackle first.

I'd go after the horizontal centering first. The 100uF electrolytic cap across it might be bad or installed backward. If so, it would likely be the source of the zipper interference too.

Well...I had a few minutes to get under the set tonight. I realized I forgot to mention one more problem. I have a vertical deflection problem also. Most of the time when I power the set on the raster is very compressed vertically. I can get it to come back by wiggling a cap on the vertical osc tube. I'm sure I can find the issue there and fix it.

I was able to find the source of the "zipper" effect in the video. I have a bad cap in the horizontal oscillator. The cap in question is an 88pf cap. I had a couple of caps in parallel with a clip lead in the circuit as a temporary replacement. When I took the clip lead out and soldered the caps in place the problem disappeared. I do need a correct capacitor to replace the defective one. Does anyone have any spares?

http://i1075.photobucket.com/albums/...psdq3nncsh.jpg

Hey, that sounds like progress!

I would definitely encourage you to forge ahead and finish the TV. Gotta love that swiveling peekaboo screen.

I know what it's like to get bogged down in a big project. I've been tinkering with a Dumont RA-102 for months now -- far longer than it would take if I had worked on it regularly rather than sulking or looking for excuses (the holidays! the cold weather! a butterfly flapping its wings in Asia!). So, do what I say and not what I do: you'll feel great when you're all done :)

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

I'd encourage you to finish this hard to find set too. I usually work on 2-3 sets at the same time, so when I get frustrated with one I pick up on another set already started. My dad repaired sets for years and he's often said, sometimes you've gotta stop and take a break or you'll drive yourself nuts.

I had a few minutes to spare last night so I looked at the horizontal centering. I tried putting a 100uf cap across the control to see if it made a difference and it did nothing. The pot reads at 10ohms and smooth from end to end. There is ~ +385VDC or so on the input, wiper, and output of the control. I'm not quite sure where to look next.


http://i1075.photobucket.com/albums/...psupy4bl62.png

Did you check out the circuitry associated with the center tap?

I think I've figured out the audio issue. I had a bad solder joint on the tone control. After reflowing the solder connection the problem has yet to return. I also realized the horizontal centering control does function, it's just that it doesn't have much adjustment at all. I don't know if it's functioning normally or not, but I do need a bit more shift than it's giving me. The raster is shifted too far to the left currently. I've been enjoying an episode of the Twilight Zone this evening trying to find any other issues. My list as of now:

1- Raster is off center to the left.
2- There appears to be a slight ripple present in the vertical.
3- There are three extremely faint vertical bars on the left side of the picture.
4- The picture focuses well in the center, but not at the edges.
5- The horizontal linearity isn't great.
6- The vertical deflection is collapsed on startup (although tonight it didn't happen)
7- There is a slight buzz in the audio (only audible when no audio is present)

I hooked up my signal generator to the set tonight so that I could get a good video of the ripple problem. With the crosshatch pattern on the screen it makes the problem very apparent. Am I correct in thinking that I should be looking at the filter capacitors as well as the capacitors in the vertical circuitry?

https://youtu.be/qYHCJpinZZY

Is there a yoke tilt screw, or are centering rings present?

Has the set been recapped yet?

Well, the audio problem is back. Here is a quick video showing the problem. The area that you see in the video is around the tone control. It's the darndest thing :scratch2:. I'm thinking something has an intermittent connection to ground?

https://youtu.be/Ne6EBEhBwso

John,
As a cathode hollows out with use, you can get non-uniform focus from left to right. Is the CRT dying?
-Ben

I've seen those old paper tubular caps develop intermittents internally where the lead joins the foil.

Sorry, I should have mentioned that all of the paper and electrolytic capacitors in the set have been replaced. They are inside the old shells...it only looks original :music:.

Decided to take a bit of a break tonight and enjoy the set.

http://i1075.photobucket.com/albums/...pscx3fdjru.jpg

Nice!

Yes, the Superb owl... First one to go into overtime.

And I went into overtime... ah, I mean I went to bed.

I was surprised this morning...

I thought I'd update my problems list.


1- Raster is off center to the left.
Still working on this one

2- There appears to be a slight ripple present in the vertical.
SOLVED! There was a power cord close to the base of the CRT.

3- There are three extremely faint vertical bars on the left side of the picture.
Still working on this. I'm going to focus on this next. I'm going to hook up my video generator to the set to test whether the problem is in the video inverter I built or the set.

4- The picture focuses well in the center, but not at the edges.
Still working on this. I like Ben's suggestion that it could be the crt itself. I have another 10FP4 that I'll swap in the set to see if it's any different.

5- The horizontal linearity isn't great.
SOLVED! This was also caused by the power cord's proximity to the crt base.

6- The vertical deflection is collapsed on startup (although tonight it didn't happen)
I'm going to call this one SOLVED! I resoldered pins on the vertical oscillator and slightly moved one of the capacitors on that tube and the problem has not returned the past 5-10 times I've turned the set on.

7- There is a slight buzz in the audio (only audible when no audio is present)
This problem is still happening, but I might just be too picky.

8-There is a loud crackle sound sporadically coming from the speaker.
SOLVED! Cleaning the tube base on the audio output tube cleared this up.

Update:

The vertical collapse is back. I'll have to continue to troubleshoot.

I have wired in the video amplifier circuit into the set in a way that could be taken back out without any sign it was there. I added two terminal strips to the set using existing bolts and nuts. I was able to jump a resistor across the existing picture control to use it in the set as it was intended.

http://i1075.photobucket.com/albums/...ps7d4e0ftx.jpg

http://i1075.photobucket.com/albums/...pssq5btv9u.jpg

I swapped another 10FP4 into the set and although it is dimmer than the 1st, the focus is better. The picture is quiet nice as is, but not yet perfect so on we go.

http://i1075.photobucket.com/albums/...pspprjwzrt.jpg

Here is the video inverter/amplifier I ended up with.

http://i1075.photobucket.com/albums/...ps0tqooz3x.jpg

I'm hoping for some help with the vertical bars on the left of the screen. The photo below shows them clearly. This anomaly doesn't go away when I remove the video amplifier circuit. Does anyone have any ideas ?

http://i1075.photobucket.com/albums/...pszdyuikm5.jpg

They look to be drive bars. A ringing in the horizontal circuit that usually changes screen brightness by modulating the scan speed. You may be able to kill it with the horizontal drive control (width and linearity settings may also effect it). On some sets it is baked into the design or the aging of unobtainium parts.

I dunno if you're trying to save all the original parts as possible, you want to hone your troubleshooting skills, or you're just a masochist, but all those old capacitors are ultimately just a multitude of tiny unknown variables.

Just sayin' :/

I'll take that as a very nice compliment. All of those capacitors are retuffed original shells. Since this is the second time that's been mentioned, I trust my method for restuffing is such that most can't tell that I've done anything (which is half of the goal in a restoration). The only modern capacitors that are visible in the set are the ones associated with the video amplifier/inverter that I added. I figured since that is a modern addition then it should have visible modern capacitors.

There is no horizontal drive control on this set :no:. On other sets I've worked on that include a horizontal drive control, adjusting it would effect a single bright white vertical line on the left side of the screen. I've not seen multiple dark lines like this before. What unobtainuim parts might create this effect? Are there troubleshooting step I can try to hone in on the source of the problem? I do have an entire spare chassis for this set from which I can borrow parts.

Transformers/chokes/yokes in the circuit.

Yep, ringing in the horizontal yoke. Check the 56pF cap or 1K resistor hidden in the yoke.

To avoid a possible wild goose chase, it might be worthwhile to ascertain that the bars are deflection-based, and not in the video chain. Shunt the CRT control grid to ground with a cap, which kills the video. If the bars are unaffected, they are in the deflection system. Cap value not critical, anywhere from .047 - .1 or so.

What! You mean you didn't wipe all that crusty old wax off so they look like shinny NOS? How dare you. :D

Could either of those parts also be the cause of my raster being off-center to the left and my horizontal centering control being pretty much non-functioning?


I'll give that a try tonight.

I don't think so. The centering control works by adjusting a DC bias current through the horizontal yoke winding. Check the voltage across the centering control and see if the voltage on the wiper changes as you adjust it.

Progress report. The horizontal centering control is broken. It stops at around 10ohm and it's supposed to be a 20 ohm control. Does anyone have a 20ohm control w/center tap and a short thumb screw shaft?

http://i1075.photobucket.com/albums/...ps7cy0audl.jpg

http://i1075.photobucket.com/albums/...psuqscd8jx.jpg

Might be able to jump a 20 Ohm across it's terminals for a temp patch.

Regarding the horizontal ringing, after shunting the crt control grid to ground to confirm the issue was not in the video, I replaced the 56pf capacitor in the yoke and while the black bars didn't completely disappear, they seemed to be less noticeable. Is it possible the cause can be coming from more than one place?

I also replaced the 6SN7 in the vertical oscillator and the vertical collapse didn't return after that. I'm going to keep an eye on it though as it went away and returned before.

stuff can work together to make horizontal ringing.

Nice!