[R-390] Sub 6AU6 for 6BA6?

[Tim Shoppa]

In several places (notably VFO and BFO oscillators) in a cow-orkers
R-390A, I notice that there's 6AU6's instead of 6BA6's.  I know that
the 6AU6 is a sharp cutoff pentode, and the 6BA6 is a remote cutoff
pentode, and suspect that in an amp (especially AGC-controlled amp) or
mixer that there'd be some change in dynamic range/AGC characteristics
through such a substitution which may not be good.  But in a simple
oscillator, does it make much if any difference?  (I know that probably
the VFO has to have its endpoint adjusted, but that's true even when
putting in a different 6BA6 so is "no big deal").

I grew up on Heath Collins Drake etc. gear of the 60's and early 70's
(how late did the make the HW-101?  Into the 80's?) that used lotsa
6AU6's (sometimes 12AU6's) for just about everything it seemed like :-).

Tim.