[Milsurplus] myster box

[Jack Antonio]

My first guess would be the receiver from the ASB
radar sets. Schematics were publishied in the
Surplus Handbooks of yesteryear.

Jack

Jack Antonio WA7DIA
scr287 at sbcglobal.net


----- Original Message ----- 
From: "Ray Fantini" <RAFANTINI at salisbury.edu>

. Their was
> a receiver about the size of a shoe box that had a ARB remote tuning
> head with right angel adapter on it and looking at it I thought that
> maybe I can sell the head on EBay so I paid $5 for it. After removing
> the head I started looking at the receiver, the more I look at the
> receiver the more I realize I have not seen anything like it before.
> There are no identifying plates or markings on the radio, it has a
> primitive coaxial cavity input directly coupled to a 955 mixer that is
> fed by a 955 oscillator tube located next to it. The oscillator tube is
> tuned by a movable signal plate capacitor that travels in a cylinder
> located on the front of the radio, this is wear the ARB head was
> connected to vary the capacitor. The size of the tuning plate is about
> as big as a half dollar. The output of the mixer ( 955) feeds the first
> IF transformer and a IF string of 6AC7 tubes, beyond the third IF stage
> is a 6J5 oscillator capacitor coupled to the grid of the fourth IF amp,
> don't appear to be a mixer, just like a injection for no reason I can
> determine. Then there are three more stages of IF amplifiers all 6AC7
> and a 6H6 configured as a envelope detector. The output of the detector
> is capacitor coupled to a 6AC7 then a 6AG7 and carried out to a coaxial
> connector. It appears to me that everything from the detector out is a
> wide band video circuit.