[GreenKeys] mystery equipment - AN/TGC-1

Thu Sep 7 23:10:39 EDT 2017

Nick, Duncan....

Not an AN/TGC-1 at all. TGC-1s were much shorter (not so tall)
and were specifically tape relay equipment, usually installed in
banks or rows. This machine is neither.

For Nick: That small reel (tape winder) you are referring to is for
TD # 1 usually located on the left side of most tape relay send equipment.
It is not a tape winder. It is a tape dispenser...feeds tape to TD # 1,
as needed each time a message is to be send via TD 2 or TD 3.
TD 1 is wired to TD 2 and 3.

It is a Channel Numbering reel. Each message that is transmitted
over the other two TDs receives and outgoing Channel or Sequence
Number before each message is sent over TD 2 or 3. This is for message
accountability at both ends. The Channel Numbering Reel has a pre-made
roll of Channel Numbers for that specific circuit. Usually (in later years)
the Channel Numbers would be composed of the last 2 letters
of the circuits Call Sign or Routing Indicator (in later years, the last
3 letters). The Numbers would usually be 3 digits begining with
001 thru 999, and then, at 999, the numbering sequence started
all over again (usually, many days later). Channel Number 000
was not used.

Ex: WX001, or AFA100, or FMA999

In short, a Channel or Sequence Number was sent from TD # 1
just before a message was sent from either of the other two TDs.
Usually, in tape relay operations, there were 3 TDs on each circuit:
1 for Numbering and 2 for Sending.

As the AN/TGC-1 and two reperforators, only one was usually
used for receiving. The other was either used for a spare, or
more often, as the "take up" or "monitor" reel for any traffic
sent thru the two TDs (2 and 3). It was thus not necessary to 
save the individual tapes off of TDs once they were sent, since 
the other reperf automatically made its own copy, and then had a small winder
to "take up" the tape copy for archiving. Relays and CommCenters
always kept copies or, the original tapes of all traffic they transmitted
(but not on the receive side, since that was the responsbilty of
the sending stations, regardless of where located).

In tape relays, archived (saved) tapes were kept for about 30 days.
In tributary stations, 7, 10 days or longer, depending on that stations
internal SOP.

Most later-date tape relay equipment featured both automatic
Channel Numbering and Automatic Take Up Reels (called 
"Monitor" reels). In particular, the KLI brands, AN/TGC-5, AN/FGC-31,
and AN/FGC-70s and the Plan 55 systems were automated with
these functions.

On the Chollas Radio Receiver site pictures, the lower-indented
sections below the radio receivers (1940s) were actually intended
for the placement of a "mill", or a typewriter that typed in all
capital letters.

This was the "human teletype" for circuits that did not yet have
teletype equipment installed and instead, used CW (Morse Code).
An operator would sit in front of the position, with his mill, and
with a set of headphones on, and as CW message traffic came
across, he would type it on the mill. Most mills used either 
multi-copy rolled teletype paper (mounted on a dispenser behind
the mill), or in later years, fan-fold paper. All of this paper was
interleaved with carbon paper (carbonless paper had not yet
come along). Some mills had stencils rather than paper on a
roll (so multiple copies could be produced for wide distribution
on a mimeograph machine. A radio op working in this fashion
was usually a very high speed CW operator (no slow pokes
here). These guys could bang out incoming messages fast
with almost no errors.....

At his position, he also had a high speed key in which to 
send QSLs back to the sending station after each message 
was received. I have known some high speed ops to be able to copy 
very fast CW, read a newspaper, chew bubble gum (and drink coffee)
all at the same time......(a testament as to how refined the art of
CW was at one time in the Army).

Such messages were then collected by an "expediter" who 
delivered them to the Terminating desk where they were
stamped, (time of receipt, security classifications, precedence),
and then given to the A&D Clerk who had them delivered to
their respective addressee. All such traffic was in normal message
format (ACP-126), generally the same as used in Army RATT
(which was a little different from CommCenter ACP-127 format which
was tape relay).

In the US Army, we had "human teletypes" until the mid 1960s
in Germany where small US detachments were located on non-US
military NATO facilties. Usually, such traffic, when sent via
HF and CW was pre-encrypted (if classified) using the KL-7.
In other situations, especially for US Army units located on 
W German Army bases which had a teletype station, US traffic
was transmitted into one of the NATO networks to reach US
stations. Again, all of these detachments had the KL-7, and
all US traffic was generally encrypted prior to transmission over
a non-US (unapproved) circuit. In the 60s, most NATO units
had either the US KL-7 or their own national version of it,
with "Allied" keylists (AKAK) while US units used US keylists
or USKAK. FWIW, the KW-7 had not yet come into widespread
use; it was still "new" to the world in the mid 60s. But, we
had KW-9s! (installed in mobile and tactical CommCenters).
(KW-9  was like an automated KL-7, except that you had one
for sending and one for receiving and could run full duplex
with them. They were limited to 60 wpm, 45 baud).

Dave

# # #

-----Original Message-----
From: Duncan Brown <duncanancy at earthlink.net>
To: greenkeys <greenkeys at mailman.qth.net>
Sent: Thu, Sep 7, 2017 9:22 pm
Subject: Re: [GreenKeys] mystery equipment - AN/TGC-1

I tried embedding a picture, but it got stripped out.  Here it is again 
as an attachment

Duncan

On 07-Sep-17 20:47, Duncan Brown wrote:
> Nick,
>
> Looks like an AN/TGC-1:
>
>
>  ( http://www.navy-radio.com/tty-relay-equip.htm), which normally had 
> two M14 reperfs & tape winders mounted on two shelves above the tape 
> reader. But in this case, there is an electronics chassis mounted in 
> place of the top M14. I don't know what the extra chassis would have 
> been for - probably some special Navy mod!
>
> Duncan
> K2OEQ
>
> On 07-Sep-17 17:08, Nick England wrote:
>> I have two 1956 photos of NAVCOMMSTA San Diego that show a triple TD 
>> and some other equipment as part of a Fleet Broadcast Operating Console.
>>
>> There something on the middle shelf of the rack above the TDs, but I 
>> can't figure out what. One view clearly shows a tape reel, presumably 
>> for winding tape after it runs through the TD, but the object on the 
>> right side of the shelf eludes me. Any guesses?
>>
>> The photos (actually, photos of photos) are here
>> http://www.navy-radio.com/commsta/sd/IMG_0049.JPG
>> http://www.navy-radio.com/commsta/sd/IMG_0039.JPG
>>
>> More photos from the NAVCOMMSTA historical exhibit are here -
>> http://www.navy-radio.com/commsta/san-diego.htm
>>
>> Cheers,
>> Nick England K4NYW
>> www.navy-radio.com <http://www.navy-radio.com>
>>
>
>
> ---
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
>
> ______________________________________________________________
> GreenKeys mailing list
> Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:GreenKeys at mailman.qth.net
>
> 2002-to-present greenkeys archive: 
> http://mailman.qth.net/pipermail/greenkeys/
> 1998-to-2001 greenkeys archive: 
> http://mailman.qth.net/archive/greenkeys/greenkeys.html
> Randy Guttery's 2001-to-2009 GreenKeys Search Tool: 
> http://comcents.com/tty/greenkeyssearch.html
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
GreenKeys mailing list
Home: http://mailman.qth.net/mailman/listinfo/greenkeys
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:GreenKeys at mailman.qth.net

2002-to-present greenkeys archive: http://mailman.qth.net/pipermail/greenkeys/
1998-to-2001 greenkeys archive: http://mailman.qth.net/archive/greenkeys/greenkeys.html
Randy Guttery's 2001-to-2009 GreenKeys Search Tool: http://comcents.com/tty/greenkeyssearch.html

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20170907/615c360c/attachment.html>