Philco 50-T1403 with focus problem

[Don Lindsly]

Roger:

The focus pot and a 150 ohm resisitor are across the focus coil. To route more current through the focus coil, make sure the voltages on the 6V6 audio output are correct. Check the 5K B+ stacking shunt and grid divider resistors.

Since the high voltage, width and vertical are OK, we can assume they are drawing the proper current, or close enough for focus.

The focus control circuitry is across the focus coil so routing more current through the focus coil requires raising the value of the shunt resistors. If the 6V6 voltages are OK, then raise the 150 ohm resistor on the focus control to about 330-500 ohms, 5 watt.

Don