[GreenKeys] How were teletypes connected across long distances?

[Sheldon Daitch]

 Chuck,
not dumb questions at all.   I will share a few thoughts that I remember regarding the Associated Pressdistribution technology from the early 1960s into the 1980s, as it applied to AP in Georgia and in NorthCarolina.

When the local radio station in my hometown in Georgia went on the air in 1960, it was an AP radiowire subscriber.  M-15 RO printer fed via a DC loop from the Southern Bell telco central office about 2-3 miles away.   How the AP circuit got to that telco office?  I really don't know, but I suspect there were both DC circuitsand tone on audio circuits between Atlanta and that my hometown in east central Georgia.
Sometime in the late 1960s, the AP in Georgia converted to a tone pack system.  The DC circuit was replaced with a voice grade audio circuit and a Lenkurt 25A single channel tone decoder - audio in DC loop out - was hooked to the M15.  
No doubt the main force in converting from a DC loop system between the local telco office and the subscriber was cost driven.    It was cost effective to convert the entire AP distribution network from DC loops to the telco, then whatever the telcos used to get the circuits to the telco office nearest the subscribersand then back to DC loops to the individual TTY machines.

I never visited the AP office in Atlanta, so I never saw what they had first-hand, but I did work in the APoffice in Raleigh as a TTY tech, in 1978.   The Raleigh bureau had a rack mounted Lenkurt 25A transmitequipment unit which could be populated with 25 tone keyers, I never had a manual on the tone layouts, but Iam thinking it was most probably 85 Hz shift.   
I mentioned the financial aspect as probably the main motive.   Consider a subscriber, that newspaper inSioux Falls.   No doubt they had a national wire for news.  Unless they ignored financial markets, they had the stock market wire.   Probably the sports wire.   Since we are discussing the old slow speed TTYcircuits, the stock market wire service was two feeds.  The stock market had too much information that at the slow speed circuit baud rates, it was impossible to feed the entire stock market report to subscriberson one circuit between the close of markets and the press deadline time for the morning news print cycle.
So, just for those four circuits, in the DC days, the AP would have to pay for four DC circuits, copper pairsfrom the telco to the subscriber.   
In going to the Lenkurt tone system, the AP needed to have only one voice grade audio pair to the subscriberlocation.   So the AP would save money on network distribution costs.

Hope this helps a little.

I suspect other folks may have additional information.

73Sheldon


    On Friday, November 24, 2023 at 10:35:22 AM EST, Chuck Robertson <hootsk at gmail.com> wrote:  
 
 
Probably dumb question:




If they didn’t have modems or routers, and the machines send and receive only by 110v current, does that mean there were dedicated wires across long distances between cities, carrying electrical pulses between sending machines and receiving machines?




Say it's 1959 and the Associated Press in New York is sending 6-bit copy to its member/subscriber newspaper in Sioux Falls, South Dakota. Is the copy actually traveling 1,400 miles on a dedicated AC or DC wire? If so, what was the wire's voltage?




Are the phono plugs in that 1942 photo of the New York Times wire room zapping careless daydreaming copy boys?




Thanks in advance.
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