View Full Version : Crosley bakelite tv


Radiotronman
11-23-2015, 10:28 PM
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.

Radiotronman
11-23-2015, 10:31 PM
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..

Radiotronman
11-24-2015, 11:57 AM
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....

earlyfilm
11-24-2015, 12:23 PM
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

dieseljeep
11-24-2015, 12:24 PM
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....

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:

Radiotronman
11-24-2015, 12:36 PM
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.

Radiotronman
11-24-2015, 12:51 PM
It's really close, just can't get it locked yet.

bandersen
11-24-2015, 12:53 PM
Have you adjusted the horizontal oscillator coil ?

Radiotronman
11-24-2015, 01:10 PM
No, I guess I don't know where it is on this set.

Radiotronman
11-24-2015, 01:15 PM
I tried filling with the trimmer in the horizontal oscillator transformer, but with no success.

Kevin Kuehn
11-24-2015, 01:26 PM
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.

bandersen
11-24-2015, 01:39 PM
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.

Radiotronman
11-24-2015, 01:41 PM
Ok, I'll try that, but how can you tell which are terminals 5-6. They're not numbered.

old_coot88
11-24-2015, 01:46 PM
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.

Radiotronman
11-24-2015, 01:53 PM
The 150K is pretty close and the 68k reads 61.5k. Would that being less cause it?

Kevin Kuehn
11-24-2015, 02:29 PM
Ok, I'll try that, but how can you tell which are terminals 5-6. They're not numbered.

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

bandersen
11-24-2015, 02:45 PM
No, that's plenty close enough.

Radiotronman
11-24-2015, 03:25 PM
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...

Radiotronman
11-24-2015, 04:01 PM
I can get the horizontal to hold for only seconds at a time.

Kevin Kuehn
11-24-2015, 04:10 PM
Did you try what bandersen suggested?

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.

bandersen
11-24-2015, 05:05 PM
If tweaking the hor. oscillator coil doesn't help and vertical is touchy too, possibly an issue in the sync circuit.

old_coot88
11-24-2015, 05:16 PM
The 150K is pretty close and the 68k reads 61.5k. Would that being less cause it?
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.)

Radiotronman
11-24-2015, 05:23 PM
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.

Phil Nelson
11-24-2015, 06:11 PM
Crosley TVs were never big sellers, although their radios were very common.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

Radiotronman
11-24-2015, 06:40 PM
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?

EdKozk2
11-24-2015, 06:54 PM
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

Kevin Kuehn
11-24-2015, 07:35 PM
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.

dieseljeep
11-24-2015, 07:45 PM
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

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:

dieseljeep
11-24-2015, 08:07 PM
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.
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:

old_coot88
11-24-2015, 08:09 PM
I can get the horizontal to hold for only seconds at a time.
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.)

Radiotronman
11-24-2015, 08:19 PM
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...

old_coot88
11-24-2015, 08:22 PM
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.

Kevin Kuehn
11-24-2015, 08:57 PM
Definitely an improvement, but from here it looks like any awfully snowy picture, like the station is not fine tuned on frequency.

Radiotronman
11-24-2015, 09:14 PM
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.

Radiotronman
11-24-2015, 09:16 PM
Audio section. Thanks everyone for all of the help so far!!

dieseljeep
11-25-2015, 09:29 AM
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:

Radiotronman
11-25-2015, 10:41 AM
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!

Radiotronman
11-27-2015, 09:45 PM
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.

Kevin Kuehn
11-27-2015, 11:58 PM
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.

Radiotronman
11-29-2015, 03:24 PM
Ok, got the audio pretty good and the set back together. Restoration complete!

Kevin Kuehn
11-29-2015, 06:04 PM
Looking good! :thmbsp: