[ARC5] CBY-46104 Receiver

[David Stinson]

-----Original Message-----
>From: Dennis Monticelli <dennis.monticelli at gmail.com>
>Subject: Re: [ARC5] CBY-46104 Receiver

>I presume the 1.5 to 3 Mc model was used for communication rather than
>navigation.  Is this true?  If so, why would aircraft use such a low freq
>for short range comm when the higher freqs would probably radiate much
>better given the short antennas in use on the aircraft?

Sorry to take awhile to reply; I've been  out of town
for the memorial for my father.

The 1.5-3.0 rig was used for both navigation and communication.

WWII was global, with many large and small powers 
cooperating at some level.
Navy aircraft radio on higher frequencies was 
a US-Western-Eurocentric situation.  
Seen from our vantage of many years later,
it seems obvious that all aircraft should have been on 
HF/VHF at this time, but only the major powers had
the resources to keep-up with the extraordinary advances
in the radio art between 1925 and 1945.
In twenty years, we went from spark sets and 
simple two-vacuum tube, low power rigs that worked
mainly below 2 MC to marvels like the ARC-1, ARC-2 
and ART-13.  But it takes money and trained workers
to produce and equip even a small navy with such wonders.
Most of the world's navies and maritime shipping- 
those of Latin and South America, 
non-client states of the Middle-East and Asia- 
with which the Allied powers cooperated, used old equipment
which conformed to the late 1920s-early 1930s standards,
assigning vessels and aircraft (with a few exceptions)
to frequencies below 3 MC.  Within the naval paradigm of the
time, this made sense, because the primary roles 
of naval aircraft in the 1920s
were short-range scouting and spotting the fall of shell.
The supposed short range of these freqs in aircraft would have been
touted as an advantage, as the enemy would (they hoped)
have difficulty intercepting aircraft transmissions.

US/UK and Allied patrol aircraft would also need
to communicate with often unidentified merchant shipping.
Few "third world" merchant vessels would have been HF-capable;
it would have been expensive and unnecessary.
A Costa Rican tramp steamer passing through the 
the Panama Defense zone would not have been able
to communicate with a patrol aircraft on 4495 KC.
Somewhere around here I have a book with all the
lower freqs in it, but can't find it at the moment.
If someone is interested, I'll keep hunting.

73 Dave S.