Checking hv

[timmy]

Originally Posted by jr_tech

I missed the connection between the vertical output and the hv supply (from the bottom of the focus pot). Perhaps io would be possible to increase vertical deflection voltage by changing or eliminating the resistor above or below the focus pot.


jr

I did try exactly that with the focus voltage and the whole screen filled in still with a picture but the focus was out of focus. Which resistor are you referring too and the hv I already lowered to around 1900v. Are referring to the focus resistor string to the focus pot.

[jr_tech]

Which resistor did you change? Is the focus voltage too high or too low now?

jr

[timmy]

Originally Posted by jr_tech

Which resistor did you change? Is the focus voltage too high or too low now?

jr

I didn’t change a resistor I jumped from the last focus resistor to the focus pot momentarily to get a full screen and the voltage was around 272v good for the 3kp1 but the d5-100 needs 800v for focus

[jr_tech]

800 volts for focus is the ABSOLUTE MAX focus voltage according to the D5 data sheet....see the typical operating conditions on the next page.

jr

[timmy]

Ok I see it I missed that

[timmy]

So if I do the diodes instead of using the tube and the voltage jumps to 180-190v there is no guarantee the deflection with fill the screen and I still would have to worry about the power supply caps

[jr_tech]

I would think that the voltage would not go that high...perhaps 150 volts or so, if the current draw is low.

jr

[timmy]

Originally Posted by jr_tech

Which resistor did you change? Is the focus voltage too high or too low now?

jr

Originally Posted by jr_tech

I would think that the voltage would not go that high...perhaps 150 volts or so, if the current draw is low.

jr

The voltage as it is now is 147v. On the d5-100 would you know what the WE is on pin 3 and AST on pin 12

[jr_tech]

Pin 3 is the grid, pin 12 is astigmatism.

jr

[timmy]

I wonder if I have the tube wired wrong on those 2 pins.

[timmy]

Finally got full screen wiring differences at the crt socket and focus voltage was to high.

[Yamamaya42]

picture = 1000 words! :P

[timmy]

Originally Posted by Yamamaya42

picture = 1000 words! :P

I’ll get the picture up I have last minute things to do. Biggest problem was obviously the crt any changes were made at the crt didn’t have to change anything with the chassis.

[timmy]

This is the best picture I could get using a cell phone it is much clearer and crisp and it’s full screen. Cell phones seem to change a lot in a picture. I had to take the picture up close because the cell phone camera seems to cancel out light.

[timmy]

There are 3 12at7 tubes in this pilot tv is it a problem replacing one with a 12ax7 I know the gain is 100 while the others are 60. Is there much of a critical balance.