[GreenKeys] Fwd: The Flying White House 1947 and SIGNIN

[DR HOUSE]

My sincere thanks to Jerry Murphy for finding out what the machine
was on President Truman's aircraft "Independence."
Those of you on the NADCOMM list have already received the hi-res  
images.
If any of the rest of you want copies reply off the list.

Please read Jerry's message below...

73,
Don K9TTY


Hi Don:

I was intrigued by the machine shown in the picture so I did some
research and here's what I found:   The machine shown in the picture
appears to be a SIGNIN combination teletypewriter cipher machine.
It was also known as the M-294.  It was capable of on-line encrypting
and decrypting but it could also be used off-line.  With the crypto
function switched out, the machine would operate like a normal tele-
typewriter.  There's more about the SIGNIN machine at the following
URL:
http://www.governmentattic.org/4docs/AchievementsSSA-WWII_1946.pdf

The article covers a great deal of material and I found it very
interesting.  There is a pic of the SIGNIN on page 116.  The machine
in the picture is in a metal case with a flip-up front.  There are
some obvious differences between the machine in the document and the
machine shown in the radio room in Truman's plane.  But there are
some major similarities.  The general dimensions of the machines are
the same and the keyboards are offset to the left.  Also, the typing
element in both machines is the same and it looks just like the one
found in Teletype's Model 31.


The SIGNIN machine had 8 rotors.  I don't know who manufactured the
machine but the article says that Teletype Corp. made the SIGABA
machine.  SIGABA was the ultra secure US crypto machine used from
just before the start of WWII until the early 50s.  The article
also mentions that.

Don, thanks for getting that hi-res picture.  Super detail.

Regards, Jerry Murphy


-----Original Message-----
> From: DR HOUSE <k9tty at dls.net>
> Sent: Feb 13, 2012 8:43 PM
> To:
> Subject: THe Flying White House 1947
>
> I finally received the original press photo of Master Sergeant Horton
> in the radio shack aboard President Truman's Aircraft "Independence"
>
> You can see more of the details in this scan.  Also attached is an
> enlargement of the aircraft's teletypewriter.  I believe the paper
> tape was printed and punched out of the left side of the unit and the
> transmitter distributor gate is above the sergeant's right hand. The
> good sergeant will be installing a new roll of tape soon ;-)
>
> 73,
> Don
> K9TTY