|
|
|
#1
03-16-2015, 11:08 AM
|
||||
|
||||
|
Horizontal tearing....what causes it?
This is on the Setchell Carlson that I just restored. First powerup without the variac, and I get this.
It locks in comfortably slightly out of phase, when I tweak it a little, I can get the lower half of the image to stabilize but the top is torn as illustrated. What typically causes this? I should note that I'm waiting for a couple caps to come in, so not every single one is fresh....
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." 
|
|
#2
03-16-2015, 11:46 AM
|
|||
|
|||
|
That is pretty extreme, but if I had to guess I would think its something to do with an anti hunt network used to filter out strong vert sync pulses. look to a RC network near the horz AFC tube grid.
I would also check to see if there is a setup procedure for setting the horz osc. could also be an issue with decoupling the vert out pulse from the power supply I would be scoping around the horz circuits looking for a vert rate pulse. Last edited by DaveWM; 03-16-2015 at 11:52 AM.
|
|
#3
03-16-2015, 12:10 PM
|
||||
|
||||
|
Fixed. Phew. Thanks for the pointer there. It was an easy one fortunately. Looked at the schematic and there was a hidden horizontal frequency control. We're good now
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia."
|
 |
|
|
Linear Mode
