[Milsurplus] Interesting manual

[Jack Antonio]

A manual showed up today for an interesting little item
I had never seen or heard of before, and since it mentions
the CBY-46145 ARA broadcast band receiver, I thought I'd
mention it on the ARC5 list as well.

The manual is for a set of three tunable converters, that convert
frequencies from 50 to 700 Mc down to 1000kc. It specifically mentions
using the ARA receiver, although it says any sensitive receiver
covering the frequency range of 700kc to 1300kc can be used.

The converter designations are CUO-46212 to CUO-46214. Each
one is about 6" x 8" x 7".

The purpose of the units is "to detect and determine the frequency
of Radar signals."

Each converter is a single 955 used as a combination oscillator
and mixer. No RF amp, or any preselection. The antenna
lead is simply fed through a capacitor to the cathode of the tube.
The book says the units have a sensitivity of approximately 50 uV.

The three converters are mounted as a unit, and powered from a
dry battery box, with a separate power cable for each unit. The manual
says that only one converter is to be used at a time. It also
mentions using the ARA receiver to power one converter at time.

Another interesting thing is that each converter had two antenna
connections, a push post style, and what the picture shows as possibly
an N connector.

It mentions that the antenna normally used for the ARA can be used as
an antenna, recommending  the "shortest one be used". It goes on to say 
that if a resonant dipole at the frequencies of interest is available, 
to  use coax line to the coaxial connector.

When I first saw the description of the manual, I wondered if this was
somehow related to the ZB homing system, but this is not the case.

The serial number on the manual is 17, so I'm guessing not too many were 
made. Manual is dated June 5, 1943.

Anyone seen one of these in the flesh?

Jack Antonio WA7DIA/4