Questions about Post-Loss Radio Analysis

[Ric Gillespie]

Wondering if there is any documentation of what the Pacific transport "route frequencies" actually were for Tx, if not 3105/6210?

Of course, in July 1937 there were no Pacific transport aircraft other than the Pan Am Clippers and they communicated only code.  I'll ask Bob Brandenburg if we know what frequencies Pan Am was using.

Bob Brandenburg replied:

Pan Am Pacific route frequencies were (in kHz):
333
375
500
1638
2986
5165
8220
8280
12330
16440

All were A1 -- CW.  No voice.

[Ric Gillespie]

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[Dick Jansen]

Bob Brandenburg replied:

Pan Am Pacific route frequencies were (in kHz):
333
375
500
1638
2986
5165
8220
8280
12330
16440

All were A1 -- CW.  No voice.

To whom it may concern:

Since "route frequencies" seems to be an idea that wasn't internationally agreed to until spring 1938 in Cairo and implemented as of Jan 1 1939, are the frequencies Bob provided documented anywhere as being applicable to Pan Am in 1937?

https://books.google.ca/books?id=_c8n-h5e9CIC&pg=PA55&lpg=PA55&dq=aircraft+route+radio+frequency+pan+am&source=bl&ots=zKaWoZXtag&sig=xqbHmBvpoPlGkZGBFHKboWzalv0&hl=en&sa=X&ved=0ahUKEwjU0J_BoO7KAhUinoMKHX2wBLI4ChDoAQgtMAQ#v=onepage&q=aircraft%20route%20radio%20frequency%20pan%20am&f=false

As to the dismissal of Pan Am M-130 voice Tx possibilities, here's a link that suggests they may have had that capability for local communication at least
http://fsim.net/b314clipper/team.htm
(second paragraph)

[Ric Gillespie]

Bob Brandenburg replied:

Pan Am Pacific route frequencies were (in kHz):
333
375
500
1638
2986
5165
8220
8280
12330
16440

All were A1 -- CW.  No voice.

To whom it may concern:

Since "route frequencies" seems to be an idea that wasn't internationally agreed to until spring 1938 in Cairo and implemented as of Jan 1 1939, are the frequencies Bob provided documented anywhere as being applicable to Pan Am in 1937?

Bob Brandenburg replies:

The source is the November 1937 Berne List of Aeronautical and Aircraft Stations.  The frequencies I provided were specific to the trans-Pacific route.  Frequencies used by Pan Am aircraft flying routes (chains) in the continental U.S. are listed separately in that document.

As to the dismissal of Pan Am M-130 voice Tx possibilities, here's a link that suggests they may have had that capability for local communication at least
http://fsim.net/b314clipper/team.htm
(second paragraph)

The news item mentioning voice communications at distances less than 30 miles refers to the Federal Radio Commission (forerunner of the FCC) regulation applicable to communications between aircraft and airports in the continental U.S.