Crosley bakelite tv
 

I started recapping my Crosley Bakelite tv. All of the wax and electrolytics are replaced. Still having issues with the horizontal wanting to lock and adjusting the horizontal hold, horizontal range don't change it much. I guess I'll starting checking resistors in the horizontal section and see if there are any out of tolerance resistors. I checked the one Meg resistor bridged across the hirizontal drive and its within tolerance. This is as far as Ive got tonight.

I also forgot to mention I don't have any audio yet, just a him from the speaker. Here is a picture of the set..

I checked all of the resistors around the 6SL7 horizontal oscillator tube and didn't find any out of tolerance. I changed the 6SL7 with a new one and no change. I double checked my cap replacements to see if i made any mistakes and they're all good. More studying of the schematic....

Can't speak for others, but I do not recognize this set.

Crosley TVs were never big sellers, although their radios were very common.

If the schematic is available on line, how about a link to it, if not, how about a scan of the horizontal section so someone who might help you could determine what circuit this set has. Just a model number could help.

A test please: By adjusting the horizontal hold, can you make the set lock in somewhere and go out of sync on both sides of where it locks in? Or does it lock in at the extreme end of its range?

James

I looked up the set in Rider's #5, which I think is the set.
The schematic shows a 6SN7 tube as the horiz osc in a syncroguide circuit.
Make sure the .01 cap across one of the coils of the synchroguide transformer is proper. :scratch2:

Sorry guys, I meant 6sn7. The model of the tv is 10-401. Below is the picture of the horizontal section of the schematic. I cannot get the horizontal to lick at all.

It's really close, just can't get it locked yet.

Have you adjusted the horizontal oscillator coil ?

No, I guess I don't know where it is on this set.

I tried filling with the trimmer in the horizontal oscillator transformer, but with no success.

Well it looks like your schematic is in Sams 95, folder 2? So if you look on page 10, there are specific instructions on how to adjust the horizontal oscillator. However I noticed a mistake when you get down to the second part about adjusting the horizontal waveform shape - at which point they start referring to L27 as L7. But without a scope you shouldn't even mess with that waveform adjustment.

One side of the coil adjusts the shape, the other side the free running frequency, That's usually the end that is accessable from outside the chassis. Set the horizontal hold control in the center and adjust that coil until you get a lock.

Ok, I'll try that, but how can you tell which are terminals 5-6. They're not numbered.

There's two resistors coming off either end of the horiz.hold control, R85 (68K) and R86 (150K). If either of these has drifted in value signifigantly, it can throw the H.hold out of range. Check these for correct value before messing with the coils.

The 150K is pretty close and the 68k reads 61.5k. Would that being less cause it?

Looks like terminals 5-6 are in parallel with R89(22k).

No, that's plenty close enough.

Ok, there was another cap stuffed behind a terminal board I didn't see connected to the horizontal oscillator transformer (.01). I replaced it and the horizontal us much better, but still unstable. The vertical is unstable as well. At least I have done firm of a picture. Now to get the sync stable...

I can get the horizontal to hold for only seconds at a time.

Did you try what bandersen suggested?

If tweaking the hor. oscillator coil doesn't help and vertical is touchy too, possibly an issue in the sync circuit.

Easy enuff to find out. Bump the value up by sticking a resistor in series with it. Try say, a 8.2K and see if it improves the lock-in range, or makes it worse.
(Of course this isn't gonna address the sync issue.)

I adjusted the end in top of chassis, but it didn't really do much. The one underneath has s partially broken s www head. But I didn't out the horizontal hold in center when adjusting the top one. I can try that.

Reminds of a page that I ran across the other day. Scroll down and look at the TV pictured for 1954:

http://www.crosleyradio.com/about

And I quote: "The first portable TV set was pioneered under the Crosley brand name, and becomes the best selling set in the industry."

What a hoot. TVs of that size (and smaller) were sold years earlier by other companies. And I seriously doubt that TV was really the best selling set in the industry, in 1954 or any other year. Never laid eyes on one, myself.

In fairness, that website has little connection with the original Crosley company. It's the headquarters for selling new repro sets under that name.

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

Ok, I tried doing what Banderson suggested and I can get a picture, but it will not hold. Constantly having to readjust to keep it close. Should I look in the sync section?

I once had a RCA KCS 68 chassis with close to the same horizontal circuit. The set had the same symptoms as your Crosley. The trouble was bad mica and paper caps in the sync circuit.
Ed

Have you tried adjusting the Horizontal Lock trimmer? Sams shows it as B2 on the back right side of the chassis? That trimmer cap sets the sync input level to the AFC portion of the horizontal oscillator. Otherwise I guess look over the sync circuit. An oscilloscope could be real handy right about now.

That set came out in the late 40's like the the rest of the E'stat sets.
The Motorola was the best seller of all of them. :scratch2:

When the adjustment screw was damaged, I would solder a 6/32 nut to the screw and use a nutdriver to do the adjusting.
The Riders for the slightly newer 12" set has a notation on the schematic, for improving the horiz hold range. Replace the 150k resistor, r87 on the Sams to a 100k and see what happens. As others have noted, the sync circuit seems to need further trouble shooting. :yes:

Could you post the schematic covering the video detector and video amp chain?
I'm wondering if there's a chance the vid.detector diode* could be installed backward. There's been a couple of such cases on this forum, and it produces a display very much like what's seen in the screen shot you posted.

*That's assuming it uses a SS diode (1N34 etc.) and not a tube diode (6AL5 etc.)

Ok I changed a 120pf mica on the 6sl7 sync clipper tube along with a pulled out of tolerance resistors. It will lose sync for a few seconds from time to time, but will snap back. I've also got to figure out where my audio is lost. It's by no means perfect, but we are getting somewhere...

Vid. detector diode's OK. Scratch that idea.

Definitely an improvement, but from here it looks like any awfully snowy picture, like the station is not fine tuned on frequency.

Yeah, this is my first experience with continuous tuners. It can be hard to completely lock in the channel you need. Any ideas on my list audio. My audio output is good(6V6) and my sound If amp(6Au6) is good too.

Audio section. Thanks everyone for all of the help so far!!

The set uses the audio output tube as a voltage divider. The cathode circuit is the source of lower voltage B+ for the IF, audio amp and tuner. See if the audio circuit is working. Maybe the cathode voltage is low. :scratch2:

Thanks dieseljeep! I started looking in the audio circuit again, but couldn't find anything wrong. Then I got to thinking about the black plug that goes to the plug on the speaker. When I got this set, one half was partially broken, leaving a couple of pins dangling from their wires. I thought I "guessed" right on where they went, but I guessed wrong. There is no guide pin on this plug, just a couple oddly spaced pins to keep it one-way. That's where the plug was broke. A little more focus and I figured it out! Audio is plenty loud and working fine now!

I've got the horizontal and vertical to stay locked and audio is pretty good. I've got to find out how to fine tune this set. Sound gets louder and better as you begin to turn the tuner away from the channel.

Looking better. You could try tuning for best picture, then tweak the primary and secondary of the sound pick off transformer(L25 in Sams) for best sound. But it looks like the top adjustment is a bugger to get at under the yoke.

Ok, got the audio pretty good and the set back together. Restoration complete!