I use it in my 40M MOPA with a Type 27 driving a neutralized Type 10 tube. You do not have to center tap it and can actually adjust the tap point for the amount of feedback need.
Is it as effective as plate neutralization? Probably not in practice but a lot better than no neutralization!
That's exactly the way they do it in the Gates BC-1 series BC transmitters, with two 833As in parallel no less. Nothing "balanced" about that final, but when I converted the BC1-T, I was surprised and delighted that I could neutralise it at 2.0 mc/s and it would stay neutralised all the way down to 1.8 without re-adjustment. Making the adjustment hold up on other bands would undoubtedly be more of a challenge, but I use it as a dedicated 160m rig and don't worry about it.
The 211 driver stage in my HF-300 rig uses plate neutralisation, but the plate-to-ground capacitance of that tube is so high that it tends to unbalance the balanced tank circuit. I placed another small variable capacitor, nearly identical to the neut capacitor, from the opposite end of the plate coil (where NC is connected) to ground. I neutralised the stage at the lowest frequency (where the split stator tank capacitor is at maximum capacitance and tube capacitance would cause the least unbalance), then tuned it to the highest frequency (20m at the time), and then re-neutralised by adjusting the balancing capacitor (bringing the circuit back into balance with the balancing capacitor. After a few excursions from 160 to 20 and back again for fine tuning, I found a pair of settings that would hold the null at all bands, 160 through 20, and locked down the variable caps. After 40 years I have never re-touched those adjustments, even after having gone through several 211s.
