Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Diagnostic & Test Equipment

We appreciate your help

in keeping this site going.
 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
  #22  
Old 12-16-2018, 12:31 PM
AlanInSitges's Avatar
AlanInSitges AlanInSitges is offline
VideoKarma Member
 
Join Date: Nov 2017
Location: Sitges, Catalonia, Spain
Posts: 446
Yes, I'm pretty stoked! PAL horiz frequency is pretty close to NTSC 15,625Hz, and just found what I guess is the intensity control on the cathode of the CRT - I'll lower it, good suggestion.

According to the service manual:

Quote:
The horizontal oscillator provides a 15,750Hz sawtooth waveform from a multi-vibrator type circuit. An internal adjustment is provided for frequency adjustment. The output of this stage is available at the HORIZ GRID DRIVE jack for injection into television receivers. The horizontal oscillator is synchronized with a sub-multiple of the 189 KHz color bar generator.
I can't find anything resembling a frequency adjustment in the horizontal oscillator circuit - could it be something besides a potentiometer?

It seems to me that R52 and R53 are the most likely causes of the off frequency, along with C101. That's what I'll check next.
Reply With Quote
 



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 08:55 AM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.