[Milsurplus] RU regenerative selectivity

[Hue Miller]

I puzzled over this situation also. Ideas that popped into my
consciousness were -
1- rebias the detector stage so that it operates as a product
detector - minimum of AM detection with BFO (HFO) operating -
and use receiver for CW only. 
2- get an old ARR-1/ ZB and convert (or place inside ) a simple
HF converter to convert HF input down to the 400 kc/s range
for the receiver main. ( However, the RU uses only 3 tuned
circuits for selectivity, so this is not all that great an idea 
either. )
3- use a 2-terminal oscillator circuit and connect to first
tuned circuit; with external homebrew control box with
regeneration control. I was just the other day looking at
a page from an old CQ that showed a 12AX7 used in this 
manner, and called a "coil-less Q  multiplier". I am sure
the circuit also showed up in Pat Hawker's "Technical
Topics Compendium",  RSGB publication.  I also have,
"somewhere", a page from PE magazine with a 2-FET
equivalent circuit.   This is the solution I would favor,
as you can finely adjust the regeneration for different
frequencies and signal levels. This circuit could be 
built and placed into the RU with only a DC level
control wire exiting. 
4- But I pretty well decided aircraft systems are not
for me, too complex with too many cables, control 
boxes, and so on, except for some A/C HF transceivers
I will keep. That conclusion means I will most likely
not keep the ARB+ATB, ARB+ATD, BC-224-A + BC-307-A,
AR-2 + AT-12.

BTW, anyone need parts from a partially scrapped
RA-10 ? Or the whole box, such as it is? ( too many 
parts gone to be restorable. )
-Hue Miller