[GreenKeys] AN/FGC-38 Torn-Tape Relay Equipment

[commtekman at aol.com]

Jim, thank you for posting info on the torn tape equipment. My AN/TGC-1 is in a brand new insulated shop and will be in a clean environment from now on, perhaps it might be possible to test some functions on it this winter-
 
Bob
 
 
 
In a message dated 8/25/2017 5:47:05 PM Pacific Standard Time, jhhaynes at earthlink.net writes:

 
 Thanks for posting that.

There are two basic architectures for torn-tape switching. One is 
represented by the AN/TGC-1 which has the reperforators and the 
transmitters in the same cabinet. The other has the reperforators
in one set of cabinets and the transmitters in another, as in the
FGC-38.

An advantage of torn tape switching in general is that the routing
information is all done by humans, so it is easy to adapt to a situation
where routing is changing frequently or requires a lot of intelligence
to figure out. The disadvantage is the need for operators to handle
all that tape manually.

The AN/TGC-1 architecture is advantageous in situations where switching
centers must be established or moved or expanded or cut down quickly.
It has the disadvantage that the routing operators get in one another's
way, and that it is extra footwork to involve a routing desk in the
process. So the FGC-38 structure is advantageous for more fixed 
installations and larger installations.

It is very common in this kind of switching to have one outgoing line
fed by two tape transmitters, arranged so that only one at a time can
be sending while the other waits for the one in use to reach the end
of tape. This allows keeping the circuit busy without the operators
having to wait for a reader to finish. Typically there is a holder to
allow a whole bunch of tapes to be queued on a sending position. I've
heard of situations where there were wires like clothes lines strung
across the switching room, and tapes awaiting sending humg on them with
clothes pins; but later more to-the-purpose hardware was developed.

Postal Telegraph Co. had a system in which there was a hidden reperforator
and tape transmitter associated with each outgoing line. The idea was
to clear the switching floor transmitters quickly and let messages queue
up in the hidden reperforator. This might have been undesirable in a
military situation where a high precedence message might pre-empt a
lower precedence message already in transmission.


______________________________________________________________
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/20170825/21034386/attachment.html>