V4 is in the oscillator module. It is a 6SA7 type.
When making pin-to-ground resistance measurements, make SURE the radio is configured like this. To locate tubes, see this.
Resistance measurements made with Simpson 260.
"Open" or "no pin" means the tube does not use the pin but it might have been used as a junction for other components.
Pins 3, 4 and 8 should be shorted together.
Pin to Radio Radio Radio chassis #5 #6 #7 1 0 0 0 2 0 0 0 3 700,000 67,000 28,000 4 700,000 67,000 28,000 5 700,000 70,000 63,000 6 0.7 0.5 0.4 7 0 .2 .2 8 700,000 67,000 25,000
Pin to From the chassis docs 1 0 2 0 3 29,000 4 29,000 5 400,000 6 56,000 7 0 8 29,000
Tube pinout images are found on tdsl.duncanamps.com
For reference:
Page: /V4/V4_new.shtml
Last modified: Monday, 1 Jun 2026