Perplexed re: Stromberg Carlson TC-19 “New Yorker”

[bigaudioal]

A few months ago, I had a customer drop off a very nice Stromberg Carlson TC-19 "New Yorker" for restoration. I had the SAMS and went to town on recapping it. I got around to testing the CRT and it was on the weak side. Zero cutoff and low emissions. Would definitely make a picture though, so I continued with the restoration. The owner had done some work on it, replacing the VOT and yoke b/c he had no vertical deflection . . . stuff owners typically do to try and get a quick fix without investigating the vertical circuit further. But I was pleasantly surprised this past weekend when I powered it up and got a decent image and great sound. The picture is backwards horizontally (text appears backwards when on screen), and thinking this is a simple crossed wiring of the horizontal section of the yoke by the owner, since he was messing with it. I need to investigate further, but otherwise decent and pretty solid operation for 2 plus hours with no obvious hiccups.

The CRT is definitely weak and the attached picture of the set working is with the brightness and contrast all the way up. So I wanted to let the owner know that he may want to be on the lookout for an available 19AP4 . . . record scratch noise!!!!!!

It was then I first noticed the base socket of the CRT says 16AP4A. All the literature I can find on this set says it uses a 19AP4. I guess I just did not notice the "6" instead of the "9" on the base socket. CRT testing settings are the same for these two tubes, so I know I got an accurate test. It sure looks like a 19AP4 and all the CRT mounting hardware in the cabinet sure looks original and unmodified. I can see no signs of alterations for a smaller CRT. I am almost certain this is a 19AP4 in disguise!!! I have restored several 19AP4 sets in the past, so pretty familiar with this tube and its size.

Guess I could always remove the CRT and measure the face to be totally 100% sure. I was thinking, is there a chance that this tube was either rebuilt and the wrong base socket was installed? Or more simply, the original base socket broke and was replaced using the wrong base socket? Anyone ever heard of a situation like this? Strange.

[bigaudioal]

Picture of set working.

[old_tv_nut]

Put it next to the sofa facing a mirror and you don't need remote control.

[dieseljeep]

Originally Posted by bigaudioal

Picture of set working.

Judging from the mask, it looks like a 16" tube.
In the early 50's there a parts shortage and the manufacturers had to make do with parts that were readily available.
Either that, the set was made from parts from two sets.

[Electronic M]

In the late 40s Stromberg Carlson was rebadging Dumont RA-103 chassis into the TV-10 and TV-12. I've put my TV-10 chassis next to my old RA-103 and they were identical aside from parts numbering.

The TV-10 used a 10BP4, a wood spacer between the chassis and CRT and an inner mask to shrink the cabinet opening but was otherwise IDENTICAL to the TV-12 that used a 12BP4.

It probably is a 16" CRT. I'd probably just measure it in your shoes.

Be glad your transformer repairs were not as backwards as a Predicta I did this fall....they had the primary and secondary swapped and I was close to pulling my hair out trying to find the circuit problem before I noticed....then I had a similar problem in the sets tuner because the 2 tubes were in each other's sockets and the service literature had it backwards too.... Horizontal was also mirrored so when I first rewired the vertical transformer I had an upside down mirrored image.

[bigaudioal]

Thanks for the replies. I had initially thought the same thing from the mask. Until I remembered that Bob Andersen posted about the exact same set some time ago. I found that thread and he definitely said his set has a 19AP4, and his set has the same mask as well. "Inside the cabinet" photos of both his set and the one I am working on look like they have the same size CRT too. If you look towards the front at the mounts and distance from CRT sides to edges of cabinet they look the same. But a 3 inch difference can be almost impossible to identify by these pictures.

Bob's thread:

http://www.videokarma.org/showthread...ght=new+yorker


Thanks for the further info about the SC sets and the Dumont sets. I bet this is a 16AP4, after hearing that things like this were done back then originally. I will just pop it out and measure it to be sure. Thanks.

[bandersen]

Here's mine and it is most definitely at 19AP4. Mask and knob spacing looks the same as yours.
Nice to know there are at least two of these sets left in the world.

[bigaudioal]

Well popped out the CRT and put a tape measure across the face. What do you guys think?

Edge to edge is 19 inches. If you just measure the viewable glass face, that is about 17 1/2 inches. Sure looks like a 19AP4 with a 16AP4 socket on it. Strange!

[bigaudioal]

Ha ha ha!

Originally Posted by old_tv_nut

put it next to the sofa facing a mirror and you don't need remote control. :d

[Kevin Kuehn]

If you measure the viewable area from the front and it's around 18" you'll know it's not a 16" tube.

[bigaudioal]

Yup, viewable phosphor coated screen diameter is around 17 1/2 inches. If it was a 16AP4 (as the socket is stamped) that area would be around 14 1/2 inches according to the tube data sheets for these CRTs. Crazy weird.

Originally Posted by Kevin Kuehn

If you measure the viewable area from the front and it's around 18" you'll know it's not a 16" tube.

[purple1]

I had to turn this over to Al. He has been great. This is my TV he is working on here. http://videokarma.org/showthread.php?t=270688

Dave

[Eric H]

I would guess the wrong base cap was installed. I'd stick a brightener on it, it would be good for years of light use.

[Yamamaya42]

Your chances of finding a replacement CRT for that are about the same as standing in your backyard on a hot cloudless summer day and getting struck by lightning.

Best bet as sated before, stick a brightener on it ans use it once in a while.