Crosley 9-413B Horizontal Issue

[Chris K]

Originally Posted by bandersen

15,750 Hz. Couldn't say how much range with your design.The trimmer is likely in parallel with a fixed cap. That cap might be too far off for the trimmer to compensate.

Does the trace look OK (like I know what I'm doing!)





It looks like the picture is getting somewhat better

[bandersen]

Looking better. Where do you have your scope connected? Service info doesn't show waveforms so I couldn't say if it is correct.

Sams here for free: https://www.earlytelevision.org/pdf/..._sams_79-4.pdf

and Riders: https://www.earlytelevision.org/pdf/...03_rider_3.pdf

B2 sets the frequency and is not in parallel with a fixed cap. I'd definitely check all the associated resistors and caps in that circuit if you're still not able to get a lock. Don't trust those 220pF mica caps.

[Chris K]

They’ve been replaced with new 1% mica caps of the same value.

[Chris K]

Originally Posted by bandersen

Looking better. Where do you have your scope connected? Service info doesn't show waveforms so I couldn't say if it is correct.

Sams here for free: https://www.earlytelevision.org/pdf/..._sams_79-4.pdf

and Riders: https://www.earlytelevision.org/pdf/...03_rider_3.pdf

B2 sets the frequency and is not in parallel with a fixed cap. I'd definitely check all the associated resistors and caps in that circuit if you're still not able to get a lock. Don't trust those 220pF mica caps.

Thanks so much for the links. I’ll go through the resistors comprehensively with the schematic from beginning to end but I have checked most of them and replaced anything that was out of spec. Every cap in the tv has been replaced and all of the micas in the deflection circuits with exact value replacements.

[Chris K]

The Riders has some great information on the specifics of the horizontal and vertical circuits including the components responsible for the sequential processing of the oscillator voltage in both. I just wish I could read the schematic! It's very blurry and the part designations are different from the readable Sams. It is, however, a great description of what happens in these circuits for a newbie like me.

[timmy]

I would double check solder connections in and around anything horizontal if there is a joint that didn’t take it could be very annoying to back track to find but worth it if you find one.

[Chris K]

Originally Posted by timmy

I would double check solder connections in and around anything horizontal if there is a joint that didn’t take it could be very annoying to back track to find but worth it if you find one.

Ahhhh...you know the quality of my soldering well!!!

[timmy]

Originally Posted by Chris K

Ahhhh...you know the quality of my soldering well!!!

No it’s not that I have made many mistakes and then having to go back and look over what I did and yes found many dumb mistakes I have made.

[Yamamaya42]

Originally Posted by timmy

No it’s not that I have made many mistakes and then having to go back and look over what I did and yes found many dumb mistakes I have made.

can't be THAT bad, I mean, you are not like this person, are you?

[timmy]

Originally Posted by Yamamaya42

can't be THAT bad, I mean, you are not like this person, are you?

Lol well he is probing for a problem

[kvflyer]

Originally Posted by Chris K

Thanks so much for the links. I’ll go through the resistors comprehensively with the schematic from beginning to end but I have checked most of them and replaced anything that was out of spec. Every cap in the tv has been replaced and all of the micas in the deflection circuits with exact value replacements.

When you replaced every resistor and capacitor with the exact value, maybe the set was adjusted in the past for a failing component and is therefore way out of adjustment.

I hate to beat a dead horse but I was lucky to find a simple problem in my RCA 630TS where the horizontal was way off frequency. I found the Horiz Freq transformer cranked all the way to one end, probably to compensate for failing components. When I put new, on value parts in, the adjustments were rock solid and in the middle of the range.

Just a thought.

[bandersen]

Absolutely! It's unusual to NOT need to make adjustments after recapping.

[bandersen]

The original Riders hardcopy is hard to read as well. Best we have unless someone has an original Crosley service manual.

[Chris K]

I had my scope connected right after the horizontal frequency trimmer. Probably the wrong spot but I do have a sawtooth at 15.75 kHz

[Penthode]

Originally Posted by Chris K

I had my scope connected right after the horizontal frequency trimmer. Probably the wrong spot but I do have a sawtooth at 15.75 kHz

The horizontal frequency is actually 15,734.26573426573 Hz. Or rounded off 15.73 kHz