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the 499J Touch Tone Dial

Started by Babybearjs, January 21, 2013, 09:53:25 PM

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Babybearjs

here is a picture of the WE 499J TT dial... does anyone have any history to this? I've never seen this type dial before? What phone did it go to?? is there any PDF file of this dial??
John

Phonesrfun

-Bill G

Dave F

#2
This actually isn't a dial, but is a set of switches which control a remote dialer circuit.  These were used on switchboards/testboards in COs.  Operators' consoles had a similar unit for dialing calls, but those controlled DTMF toll dialing equipment, and they had additional keys (KP,ST) required for DTMF dialing.

DF

edit:  As noted later posts, my use of DTMF refers to Multifrequency Keypulse (MF) used in the toll dialing network, and not to the more-familiar touchtone frequencies.

paul-f

The switches were used on switchboards for early operator tone dialing and other supervisory functions.  The oscillators they controlled were large in pre-transistor days, so couldn't be used in subscriber telephone sets, let alone be built into the dial.

You can learn more than you ever wanted to know from A History of Engineering and Science in the Bell System, Switching Technology (1925-1975).  Look for topics like Operator toll dialing and MF signalling.

There's a short summary of the history of the MF codes used part way down the page here:
 http://www.paul-f.com/we1948pb.html

and more in the December 2008 TCI journal, Singing Wires.
Visit: paul-f.com         WE  500  Design_Line

.

G-Man

Not a DTMF dial but instead a keypad for MF-Signaling (Multi-Freqency)  for operator dialing over the toll network. DTMF and MF used different frequencies.\

   DTMF-
        http://en.wikipedia.org/wiki/Dual-tone_multi-frequency_signaling

   MF-
        http://en.wikipedia.org/wiki/Multi-frequency_signaling

Babybearjs

interesting... from a switchboard huh? does anyone have any pictures of it installed in a unit?
John

Adam

I believe the buttons in the foreground of this picture are an example of the kind of operator switchboard dialing buttons we're talking about.
Adam Forrest
Los Angeles Telephone - A proud part of the global C*Net System
C*Net 1-383-4820

paul-f

Here's one of a NYC Toll board.
Visit: paul-f.com         WE  500  Design_Line

.

Babybearjs

Interesting Photos! so that's what that's for....
John