Crosley Model ??
 

I picked this up on ebay earlier this year and decided to hold it for a winter project. I'm between projects now and am off work this week, so I thought I'd at lease assess it. I have done a power up and get static in the audio but no raster or signal neither on TV or FM.

Anyway, there is no model # on the set. I see a similar looking set on the ETF database. Does anyone know what model this is. I'd like to look at the schematic before pulling the set from the cabinet.

Thanks
Doug

Looks like one of the 9-403 variety.

http://www.earlytelevision.org/pdf/c...403-rider3.pdf

Unfortunately that Riders scan is very difficult to read. It should also be in
Sams 79-4

Crosley 9-403
 

You're right Kevin, the Riders posted is hard to read. Maybe I can locate a Sams, which I'd rather use anyway.

So far, I've removed it from the cabinet and found it caked in dust EXCEPT for the octal tubes which I assume are or the horiz and vertical and rectifier. Those are perfectly clean which makes me think someone tried to work on it and gave up after replacing some tubes. I haven't turned the chassis over yet to look underneath.

That likely is a Crosley badged Dumont chassis.

Well I just finished familiarizing myself with it underneath, and it looks to be unmolested. It looks like all the aps are the original ones. I am going to carefully start replacing the paper caps and check the CRT. The base is loose, so I'll need to re glue it.

One thing I do find odd, is that it does no have a Hi and Lo switch for the TV tuner like other continuous sets have, just a TV and FM position.

Doug, pm me your email and I'll try to send you a scan of the Sams later tonight. Will also send it to the ETF so it can be downloaded.

Yep, I believe Kevin is right.

I have the same set in blonde if any buddy want to make a offer on it let me know.

It's more like a quasi-clone of a Du Mont. Du Mont never offered any set with a 10" screen, nor in that particular configuration. But yeah, Du Mont engineering slightly re-envisioned.

If it's a DuMont RA-103 clone (or near-clone), that wouldn't be surprising. My RA-103 doesn't have Hi-Lo switches for TV channels, either.

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

I was up around 2AM this morning replacing paper caps. I've got about half of them done. I haven't done any electrolytics yet because I've got to order most of them.

The good news is I now have high voltage. The fuse in the damper circuit was open, and I just replaced it and the results are shown. Also both candohms are good.

The bad news is my 10BP4 is not usable. I put it on the checker, and it barely had any emissions. I accidentally bumped the connector, and the socket cap came off. Trying to repair that resulted in a lead breaking off right at the glass. I'll have to locate another CRT when restoration is near completion. Right now, I've got my 5" test CRT in place.

I still can't get a signal to come thru either on TV or FM.

I wanted to give a progress report. I just finished restuffing the last electrolytic can (4 cans total). I've got 2 tubular electrolytics to replace still. One is in the audio section, and one is a filter in the focus coil network.

All I can get is a horiz line across the screen. I've replaced all caps and most resistors in the vertical circuit. I was hoping this last electrolytic can would solve that as 2 sections were tied into the vertical.

I am now getting an audio signal, but it is way off on he continuous tuner. Ch 3 (cable) is coming in below channel 2. The FM band is coming over the TV band starting around Ch 5. Nothing is coming through with the band switch in the FM position.

I hope the tuner is not out of alignment. I read the alignment instructions today, and the Sams said the tuner is so difficult to align that it recommends replacing the tuner instead of realigning it.

Right now, I need to concentrate on the vertical section and try to get an image on the screen.

The vertical issue was caused by a bad 6SN7 vertical tube. I finally have a raster but that's it. No video signal. The audio signal is a little distorted, but I'm hoping the electrolytic in the audio section, that still needs replacing, will clear that up.

The retrace lines seem to react when I tune the Tv into a station even though there is no video signal.

Sounds like you've got a sync signal getting to the sweep circuits, but no video to the CRT. The video is DC coupled from the plate(pin 6) of the Video amp(V8B), through L24, then directly to pin 2 of the CRT. L24 is a 4.5mhz sound trap. You could check L24 for continuity, or even try a jumper across it.

First thing I did was try another 12AU7 which did nothing. The voltages on that tube are in line. I'm having to use the voltage chart in Riders instead of Sams. Sams has me checking some voltages with the negative on pin 6 of V15. That is giving me a zero reading. Riders is having me check against ground, and the voltages and near normal. I had that same problem when I checked the voltages on the vertical output tube.

Anyway, pin 6 gives me the right voltage. L24 has voltage on each side and checks good. Also tried jumping it which didn't help.

Is there any snow in the picture, or only a raster?

This TV has split sound - the sound picks off the plate of the 1st video IF. So your signal is at least getting through the first video IF amp. I guess I'd try changing the 2nd and 3rd IF tubes, and the video detector. Next measure voltages on those socket pins.

Ok, after changing both the 2nd and 3rd IF tubes, I now have a video signal. It's not good, and the audio is still distorted. The 20uf electrolytic in the audio came in, but that didn't help. I'm still waiting on a 16uf filter in the focus coil circuit.

Actually your scan lines look pretty well focused. Maybe try a composite video signal hooked directly to the grid of the video output tube?

Assuming direct video in gives a good sharp image, then it looks like somebody may have twiddled with the IFs.:eek:

I think I've got the picture as good as I can get, but the sound is still somewhat distorted.

It sounds like an intercarrier buzz which tweeking the audio Ifs will not get rid of. Any ideas on how to clear up the audio?

There is no intercarrier, so that can't be the source of the buzz. Are you using a balun? Try connecting the 75 ohm coax directly.

Did you try it yet?

Yes, it didn't help. Today I'm gonna put the signal tracer on the set staring at the grid of the 1st IF tube and see what I can find.

Another problem has developed. The horizontal is very unstable. Sometimes, I cannot even get it to sync even though besides the hold control, there is a trimmer for a horizontal lock, drive, freq, and a coil for the horiz lin.
I left the set on for 20 min while I was troubleshooting, and the width shrunk and no sync was the result. See pic

I have now lost the raster completely. I finished replacing the mica caps in the horiz osc section as well as resistors. Voltages on the 6SN7 check ok. Tried another 6Sn7 as well as a 6BG6 output and 1B3. Any ideas? Here is the horiz section on the schematic.

Well if it quit after you changed the Micas I see two possibilities.
1. You got something wrong. :)
2. The values are different from the originals, possibly because the originals were bad, now the frequency is so far off the oscillator won't run. Try adjusting the H Osc coil.

Eric, that post was confusing. The raster quit while the set was playing. I then replaced 3 micas hoping one of them had gone bad.
First, the horizontal lost stability, then I lost sync altogether. Next the pic shrunk (see pic 2 posts ago) then I lost the raster completely.

If you Have a scope check and calibrate (by comparing the freq to video synch) the osc. If that don't fix it check voltages on the H out tube, and if those are fine check the damper tube. A shorted or weak damper will kill the raster.

I don't have a scope, so I checked the voltages on the 5V4 Damper. Pin 2 is low about 45V. I don't have another 5V4, but my tube substitution guide says a 5U4 will sub. I want to make sure of that, then I will try a 5u4 in it's place.

My Dumont uses a 5U4 for a damper, and this set seems to be a dumont inspired design so it will probably work.

A 5U4 pulls an extra amp on the filament supply.

Oh okay, I though it quit after replacing the Micas.

I've used a 5U4 in place of a 5V4 Damper temporarily, it worked fine but I was advised not to leave it in permanently.

I'd sooner use 5Z4 (preferably) or 5Y3 as a temporary sub if I had to.

I briefly tried a 5U4, and that didn't help. Pin's 2 and 8 should have 300V and both have about 255. Pin 8 has a fuse (which is good) that goes to the horiz lin coil. I put the HV probe on the cap of the 6BG6. No HV, but when the probe touches the cap, I can hear it cackle in the speaker.

After a break, I have gotten back on this and found a mistake I made. An 8200 ohm resistor was going to pin 5 instead of pin 6 of the 6SN7 horiz osc tube. Correcting that now gives me a partial raster as shown.

Any ideas on why only 1/2 of my screen is lit, and where to start troubleshooting?

I've gone as far as I can. I think the horiz is running off frequency. I can see what looks like a blurred overlapping image on the screen. I checked the horiz hold control, and it's fine. The horiz lin control measures good. I even replaced the 56pf cap on the yoke for the horiz. I posted most of the schematic, but the hoirz and HV section can be found on PG 2 of this thread at post 10 that starts as "I've completely lost the raster." It wouldn't let me repost the same pic again.

If someone recognizes the problem or has any ideas of that's wrong, please advise me as I'm about to give up on it.
Thanks
Doug

Also, this set has 3 trimmer caps. Horiz lock, horiz drive, and horiz freq. Lock and drive have to be screwed in almost completely or I lose what raster I have. Freq seems to make no difference.

Get rid of those two candohm resistors underneath, no matter how they test. I just went through hell with a somewhat similar issue.

Judging by that picture it appears to be scanning top to bottom, not side to side.
Is it possible the yoke has been turned 90°?

If that's the case then the vertical is short, not the horizontal, though that may be off frequency.

Eric, the yoke is not off. I was getting a good pic, then lost the horiz sync, then it shrunk. I did take the yoke off to replace the 56pf in the yoke windings, but I put the yoke back on correctly.

On the Candohms, what's in there are still the originals. I did have a replacement for the 350 ohm, and I just installed it. Still no change. I can see an image on the screen, but it is very blurry. I'll have to get a replacement for the other candohm.

Doug

While I hunt a suitable replacement for the other candohm, I'm wondering if the yoke could be bad and causing this problem. During the whole time I have been working on the set, the raster never filled the screen completely to the left. It always lacked about 1/2 inch then got wider as I lost the horizontal sync finally giving me what I have now: just 1/2 of the screen lit on the right side.

The Sams does not give the ohms for the yoke however.
Crosley# AB-144901. crosses to a Stancor DY-1.

Thanks
Doug