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Rotary Single Slots and Touch Tone 3 Slots

Started by Protel8000, September 29, 2018, 01:13:29 AM

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Can anyone help me understand the history of the switch over from rotary to touch tones on payphones? I (probably incorrectly) associate 3 slots with rotary phones and single slots coming into play in the 70s along with touch tone phones. But I've seen a lot of photos of single slots with rotary dials, and three slots with touch tone dials. Was there a lot of overlap during this switch over where single slot phones were becoming common but in areas that didn't yet have touch tone dialing? Were the touch tone 3 slots upgrades to keep them in service longer?


Just because a single slot is rotary, doesn't mean that it came out before tone. Some exchanges were still rotary, where others were tone.
I don't know the exact time line, I'm sure there are others who know more. But single slots actually came out in the mid sixty's more prevalent in the 70's. I've seen places with independent companies still had three slots in use until the mid 70's around here.
History tells of single slots being developed in the 60's.

Payphoneinstaller could give you more information, at some point.


Thus a TT 3-slot and a Rotary Single Slot are generally the harder to find items.

It wasn't the need for a TT payphone that led to the total redesign but rather it was the increasing need for a harder to break into payphone that led to the superior design of the new single slot payphones. And yes, the quick and easy way to get an existing rotary 3-slot upgraded to TT was to replace the upper housing with a new TT model if Security hadn't yet become a major issue at the location.



My father worked in the coin department in the early 1970s, and they had been slowly upgrading to single slots, a mix of Touch-Tone and rotary, but they removed all of the remaining 3 slot phones when they were raising the price from 10 cents to 15 cents, as the single slots were easy to reprogram for price changes.  Though all the exchanges around here had been Touch-Tone for a long time, I remember seeing rotary single slots in use in the 1990s.

Jim Stettler

In Colorado Springs they put in 10 cent single slot rotary's in place of 10 cent 3 slots. I got a WE 236 3-slot from a local installer. He said when they converted from 3 slot to single slot there was unlimited overtime available to the payphone installers. He said everyone on the crew kept a 3 slot as a souvenir.
When they raised his insurance rate it made him  so he sold the phone.

Most of the 3 slots were black and most of the single slots were green. It was probably early to mid  70's when they made the switch over. They started with the highest traffic telephones first.
Jim S.
You live, You learn,
You die, you forget it all.