Quote:
Originally Posted by old_coot88
That's the control grid (G1). It should rise to around 100-115V as you advance brightness to maximum. Does it?
In other words, its bias relationship to the cathode (pin 11) should be at or near 0V at max brightness.
What is the voltage directly at the brt.control wiper as you turn the control stop-to-stop? What is the voltage at the top (hot) terminal lug of the control? Just for the heck of it, check for continuity in the wire going from the wiper to pin 2 (just on the chance there might be a break in that wire).
|
Thanks again everyone here is what I found...
on the far end of the 100K resister (R35) it reads 330 volts, after it crosses R35 the voltage drops to 0.69 volts which is the input to the Brightness Control. The wiper of the brightness control seems to vary the voltage from stop-to-stop at 0.04 volts at min to 0.67 volts with the dial turned to max and this is what is output to Pin 2 of the picture tube cap. The continuity of the wire is just fine, but always good to check! Old_Coot88 are you saying with the brightness turned up Pin 2 the output of the wiper should be 100 to 115volts? If so 0.69 volts is obviously way off.