Checking hv

[timmy]

Originally Posted by jr_tech

Did the vertical scan improve when you increased the B- supply?

jr

I didn’t increase the voltage because it was at 147v and if I got the voltage up it may have been to much for the power supply caps.

[jr_tech]

lAccording to the data sheet for the D5-100, the deflection sensitivity is about 100volts per centimeter when operating at 2000 volts. I believe that the hv in the Pilot is closer to 2500 volts, which would reduce the deflection sensitivity to around 125volts per centimeter.

http://www.r-type.org/pdfs/d5-100gh.pdf

The vertical height of the D5 is about 3 centimeters, so it would require about 375 volts to scan from top to bottom of the screen.

The voltage that you have available from your B+ and B- supplies, which power the vertical circuit is less than 300 volts total, so you can’t achieve a full vertical scan.

jr

[jr_tech]

Originally Posted by jr_tech

The voltage that you have available from your B+ and B- supplies, which power the vertical circuit is less than 300 volts total, so you can’t achieve a full vertical scan.

jr

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

[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.