Predicta Princess Networks - Videokarma.org TV - Video

Jon F · #1 01-24-2015, 11:49 PM

Just finished replacing paper and electro caps and some bad tubes in a princess, so far so good the picture is pretty nice and stable. Some horizontal linearity issue that won't clean up but otherwise OK.

I'd like to do some preventative maintenance if necessary. Are any of the networks more prone to failure than others? If so I'll replace those and leave the rest alone.

Thanks!

JBL GUY · #2 01-24-2015, 11:51 PM

Nice!

Thanks for the pictures.

StellarTV · #3 01-25-2015, 02:47 AM

Vertical feedback network- always. It's the smallest one next to the vertical output tube and easy to replicate.

Jon F · #4 02-14-2015, 09:31 PM

Quote:

Originally Posted by StellarTV

Vertical feedback network- always. It's the smallest one next to the vertical output tube and easy to replicate.

Thanks, I took your advice and replaced the vertical feedback network. I also noticed some instability in the horizontal hold, it would radically jump around when changing channels or fine tuning. Replacing the horizontal multi network took care of it.

Attached an operating photo

Don Lindsly · #5 02-14-2015, 11:07 PM

Align the horizontal oscillator according to the Sams or Philco instructions. That must be done regardless of any other troubles. It may make a big difference.

miniman82 · #6 02-15-2015, 10:49 AM

Is it me, or does it seem stretched vertically? I think the scan lines could be a little closer to each other, but other than that looks like a nice picture.

Jon F · #7 02-15-2015, 03:37 PM

Quote:

Originally Posted by miniman82

Is it me, or does it seem stretched vertically? I think the scan lines could be a little closer to each other, but other than that looks like a nice picture.

It was, I had my source set to widescreen on accident; realized it after, and readjusted geometry

wa2ise · #8 02-15-2015, 04:18 PM

Quote:

Originally Posted by Jon F

It was, I had my source set to widescreen on accident;... and readjusted geometry

What you had before you corrected it was a rough simulation of the pre-war 441 line standard, before the FCC upped it to 525 lines. Had they stuck with 441 lines, the horizontal frequency would be about 13KHz, which people would hear worse than the 15.75KHz flyback whine.