[Hallicrafters] Hallicrafter_USWB

[james rea]

Gentlemen...

Trying to determine what Hallicrafter radio was used by the United States
Weather Bureau for upper-air radiosonde soundings during the 1940's. 

The radiosonde receiver was tuned to 72.2 mHz during the 1940's (converted
or replaced to 403 mHz in the early 1950s). Hallicrafter and National Radio
manufactured the radio receiver units. Bendix/Friez made the radiosondes and
ground units. A picture and diagrams attached.  The radio was installed in
the top rack slot.

The radiosonde ground equipment was described as follows in an old 1940's
meteorology handbook...

"The major components of a radiosonde receiving and recording equipment are
an antenna system, a receiver, an electronic frequency meter, and a
recorder.

A vertical half-wave dipole antenna is used and is connected to the receiver
by a gas-filled or solid coaxial transmission line.

In Fig.44, the top unit is the receiver, the next is the frequency meter and
beneath that is the recorder.  The receiver is of the superregenerative type
and is equipped with a tuning meter, a loud speaker, and a special audio
amplifier the output of which connects to the frequency meter input.  The
frequency meter has one stage of amplification that controls two thyratron
tubes.  These thyratrons are connected to push-pull and alternately
discharge capacitors though a diode rectifier and indicating and recording
meter circuit.  The frequency meter input switch allows the input circuit to
be grounded or connected to 60 cycles, thus permitting checking the zero
point and point corresponding to 60 cycles on the recording scale."

The 1940's USWB station description forms list small details of radiosonde
serial numbers, but fail to identify the entire ground units other than by
frequency used and radio manufacturer. 

The military appears to have used similar units in what appears to be
labeled the FMQ-1...though apparent upgrades over the years makes putting
the pieces difficult for me.

Any help would be appreciated.

jar