Personal Interest & Recollection of
North Pittsburgh Telephone Company
Part 1


A personal interest and recollection of the former North Pittsburgh Telephone Company from the Telephone World webmaster's perspective

Why the personal interest with the
North Pittsburgh Telephone Company?

Why in the world is the Telephone World webmaster so intersted in a small independent telephone company? The answer is simple – I used to live in the area served by this phone company.

Back in January 1982, I moved to Gibsonia, PA and was served by North Pittsburgh for telephone service. Prior to this, I lived in western Washington state, which was served by Pacific Northwest Bell (later US West, now Qwest). As was the case for most “modern” Bell areas, the area was served by #1AESS and #5 Crossbar switches. These for the most part were quite boring and not much character to them.

But, back in the early to mid-1980s, North Pittsburgh and the surrounding area (United Telephone (now Sprint) for the north, for example) had a variety of switching types – Step by Step, Crossbar and early electronic switches. These provided character to what normally was a mundane system.

I lived in the Gibsonia exchange area, which at that time was served by a #1EAX (Electronic Automatic Exchange) which was Automatic Electric’s first electronically controlled analog switch (invented circa 1972), which was in service from April 1977 through June 1987.

North Pittsburgh sported several switching types, even their service territory was quite small. Their main switch (Class 4 tandem) was the aforementioned #1EAX, which provided relief for the overloaded Step by Step switch which also served the Gibsonia area. Nearby rural exchanges were also Step by Step (aka Strowger), while more populated areas were second-generation analog electronic #2EAX switches – again all were Automatic Electric.

So the variety of the sounds of how calls progressed through these various systems as well as the different types of centralized and automated intercept recordings caught my "ear" and the experimentation began.

Dialing calls from the #1AEX, you heard either clicks or tones as the call progressed. It wasn’t until I was in my 20s and 30s before I really knew what was going on back then, but even as a teenager I had a pretty good idea what was up at the time. The tones (Multi-Frequency Tones) let you hear what was going on for inter-switch communications. The clicks (dial pulses to the step offices) also showed you the technological limits of these switches. 

The pay phones were also different. Not the Western Electric fortresses that I grew up with in my early childhood, but the Automatic Electric variant of the fortress were in fairly large quantity instead. In fact, there were several old three-slot Automatic Electric pay phones in the North Pittsburgh until the late 1980s!

By the early 1980s, North Pittsburgh retired their old cordboard operator system. Connection to the AT&T’s (Bell System) Youngstown TSPS (Traffic Service Position Station) operator services platform was performed in May 1982 – and all the Gibsonia pay phones were moved from the Step switch to the #1EAX. All pay phones at that time were changed to “Dial Tone First”. Again, this led to more experimentation.

One by one, the older switches were replaced by more advanced digital switching technology. June 1987 was when Gibsonia bid farewell once and for all to the #1AEX (and its Cognetronics brand of Automated Intercept System) and onto the Northern Telecom (now Nortel) DMS-100 based switching system. But that also gave way to even more experimentation.

And so goes the story… from experimentation and satisfying curiousity, and onto seeing what I could get away with….

Next Page – Making “free” phone calls...and also getting caught.

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Page last modified December 20, 2008
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