1958 RCA 14-PD8057 Horizontal Issues/Circuit Board Nightmares

[Chris K]

Broken trace. Fixed with a jumper. Waveform looks perfect but, I'm only at around 13KC not 15.75 and I can't get the horizontal dialed in. Vertical locks and is fine. Distorted and wild messed up crosshatch off my generator. Three adjustments in the horizontal circuit...width, waveform and horizontal hold. Maybe the oscillator is weak. I'll test it.

EDIT: Looking at the caps in the horizontal. There are 3 mica caps, 2 at 1000pf (C99 C100) and one at 330pf (C98). I didn't replace any of these but someone did replace C99 with a 5% cap but not a mica...at least not that I can tell. It It's a rectangular cap like one of those safety caps and says CD Type Made in USA 5 Amps on the top...5% and "D" printed in quotes on the face. There's more including the uF but there's a bunch of crap in front of it and I can't see it. Definitely not what's depicted in the photo of the board in the Sams.

[Yamamaya42]

Originally Posted by Chris K

Broken trace. Fixed with a jumper. Waveform looks perfect but, I'm only at around 13KC not 15.75 and I can't get the horizontal dialed in. Vertical locks and is fine. Distorted and wild messed up crosshatch off my generator. Three adjustments in the horizontal circuit...width, waveform and horizontal hold. Maybe the oscillator is weak. I'll test it.

EDIT: Looking at the caps in the horizontal. There are 3 mica caps, 2 at 1000pf (C99 C100) and one at 330pf (C98). I didn't replace any of these but someone did replace C99 with a 5% cap but not a mica...at least not that I can tell. It It's a rectangular cap like one of those safety caps and says CD Type Made in USA 5 Amps on the top...5% and "D" printed in quotes on the face. There's more including the uF but there's a bunch of crap in front of it and I can't see it. Definitely not what's depicted in the photo of the board in the Sams.

Why am i having this sudden feeling of dejavu?
cause I just went trough this with my maggy?
C99 looks like it may be just a decoupling capacitor, not sure.
Critical one are C94,C95,C96,C98 and the resistors in the area, C93 passes the sync pulses down from the sep amp, so if it's not right you won't have lock or weak lock, C100 passes the signal to the output, the problem is prob in a the AFC area, if the caps or resistors are bad / out of spec, it's not allowing the PLL circuit to work correctly and thus out of frequency.

[Chris K]

Not to fixate on C99 but I was able to move things around a bit and it looks like the cap is a 0.01uf cap and not 1000pf. C93 on my CB is a ceramic cap but I can't make out the rating. Supposed to be 82pf. I do have an 82pf mica I could substitute for it. I really don't have any way to test the ceramic. Externally it looks fine. There is another ceramic next to it that's not in the Sams Photo or component list so there might be different versions of this model.