[Heathkit] DX-100 - 0A2 replaced with 0B2?

[Rick Poole]

The 0A2 VR tube in my DX-100B was replaced by a previous owner with a 
(lower-voltage) 0B2 (150V vs 108V).

Do any of you know of an aftermarket modification that involved doing that?

I've gone back to the 0A2 and it seems a little more stable.

Rick WA1RKT