V4B - Dual Bias Control - External Set Up

[Roman Ships]

I have a 1971 V4B and I'm adding adjustable bias control with external test ports and pots.

I could use some input advice.

Cathode Test Ports:
I was planning on putting a test port with a 1 ohm resistor from cathode to ground for each tube. I have seen it done with linking the left two cathodes and the right two cathodes. Thus you could divide the current by 2 and get an average. But then I wouldn't know which tube is pulling more current. Is 4 cathode ports totally unnecessary?

Control Grid Test Ports (Bias control):
Since I want to bias the tubes in pairs i would swap out R35 & R36 (100K) for 75K and install a 50K Trim Pot in series with R35 and R36 respectively.

So I would need two test ports here, choosing one control grid pin per pair of tubes. Or do I need none since I really only care about current through the cathode?

Plate Voltage Test Ports:
One Test port and assume they are all the same given all the plate resistors are functioning correctly.



Does this sound like a good plan? I see people usually put a pot in with R49 but I assume that is just because it is the most convenient location if you are biasing all four tubes together.

Any advice / feedback would be excellent.