01-28-2022, 11:29 PM
Why do you think there should be 400V on the .22 uF cap at the 3CB6? I don't see any connection to the 400V supply.
From what I can see, voltage to the .22 uF cap is sourced from the 275V supply through the 120 ohm resistor. That's why there is no voltage on the circuit when you disconnected the resistor. So the voltage supplied through the 120 ohm resistor then flows from the common connection at the .22 cap back through the cable to the main chassis then through the 1500 ohm and 3300 ohm to the 6AN8 video amp and to the N1 network. So the 120 ohm resistor supplies voltage to the 6AN8. The network supplies no voltage as it has an internal cap at its input and only receives a video signal from the 6AN8.
The voltage on the .22 at the 3CB6 is slightly low, probably because the 275V supply is low, but not maybe that significant.
How much voltage do you measure at the 3CB6 plate and CRT cathode?
From what I can see, voltage to the .22 uF cap is sourced from the 275V supply through the 120 ohm resistor. That's why there is no voltage on the circuit when you disconnected the resistor. So the voltage supplied through the 120 ohm resistor then flows from the common connection at the .22 cap back through the cable to the main chassis then through the 1500 ohm and 3300 ohm to the 6AN8 video amp and to the N1 network. So the 120 ohm resistor supplies voltage to the 6AN8. The network supplies no voltage as it has an internal cap at its input and only receives a video signal from the 6AN8.
The voltage on the .22 at the 3CB6 is slightly low, probably because the 275V supply is low, but not maybe that significant.
How much voltage do you measure at the 3CB6 plate and CRT cathode?
