[ARC5] [Milsurplus] Opinions on ARR-7

[Geoff]

I did make one small
> modification to it - jumpered plate and grid of the anti-radiation
> isolation stage with a small mica capacitor soldered to a couple of tube
> pins inserted into the tube socket. The original design simply added a
> bunch of noise to the receiver without any useful purpose.  I made the
> same change to the ARR-5 input stage.  Pairing with an AN/APA-10
> panadapter and an APA-6 or -11 pulse analyzer is an interesting thing to
> do if you have the space and power.  I normally use it with an
> interphone amplifier to get the power for a speaker - the LS-184/AIC-10
> - but any outboard amp can of course be used.

The Navy was paranoid about oscillator leakage being picked up by the enemy 
and had many receivers modified with an additional RF stage, tuned or 
untuned. From what Ive read on the subject it is highly doubtful that the 
enemy had sufficient technology during WW2 to detect it unless they were 
well under a half mile away.

Perhaps, also, the ARR-7 was deliberately desensitized to limit interference 
from distant signals as well as minimize images due to only a single tuned 
RF stage that plagues many receivers on the higher frequencies when using 
only a 455kc or similar IF.