News:

"The phone is a remarkably complex, simple device,
and very rarely ever needs repairs, once you fix them." - Dan/Panther

Main Menu

Switch from pre/post-pay to dial tone first, vs. three/single slot payphones?

Started by AdamAnt316, September 16, 2014, 12:38:18 PM

Previous topic - Next topic

AdamAnt316

Hello, everyone. Being a child of the '80s, pretty much all of the active pay phones I've ever seen were single-slot touch-tone types, and they all used the dial-tone first system. I've been wondering as of late, about when did the switchover from pre/post-pay to dial-tone first take place, and how directly did it coincide with the switch from three-slot to single-slot payphones? I originally thought there was a direct switch, but the fact that early single-slot payphones like the 1A1 were set up to work with pre-pay systems makes me wonder. Also, were any three-slot payphones ever set up to work on dial-tone first systems? Finally, about when were the last three-slot payphones taken out of service? Can't recall seeing a topic on this forum about this yet, so figured I'd ask.
-Adam

Kimball321

Well the first test of dial tone first coin service occurred in 1966 in Hartford Connecticut (which ironically had been the site of the first pay phone installation in 1889).  A few months later another trial was conducted in Greenwich Village NYC and the next year (1967) in Danville IL every pay telephone within the exchange was converted to DTF operation.  All three of these trials involved crossbar switching (#5 crossbar in Hartford and Danville, #1 in Greenwich Village).  Also the first two installations involved tsps systems for operator services but in Danville cord boards were still in use.  The next year (1968) the decision was made to convert to dial tone first operation all across the Bell System at a total cost of 80 million dollars (in late 1960's dollars!) which in 2014 would be 684,626,436.8 dollars!  That year the first non trial conversions began in NYC and the Washington DC area, all on #1 and #5 crossbar switching.  Dial tone first operation was available on all types of automatic switching systems except panel switching and in most cases the coin lines could be routed to another nearby non panel office.  According to another member of this board (E. Slater) the change over was mostly completed by 1980 however I have seen evidence that coin first service made it to at least December 1985.  Also an 1994 article mention's that coin first pay phones probably no longer existed by that time.  However outside the United States in Japan some of the older payphones known as "pink phones" require a coin even to call an emergency number so those could be considered to be coin first, however I believe they work differently from our coin first pay phones.  Post pay pay phones still exist in the United States at least for desk top COCOT's I just saw one a few months back at the Milwaukee Greyhound Station.  Also in an article from December 2013 there is a photo of what looks like to be a post pay Nortel Centurion located in Headwaters Virginia inside the national radio quiet zone where cell phones are banned.  According to the 1994 article 3 slot pay phones existed to at least 1993, at least with independent telcos.  I am not sure if any 3 slot pay phones were ever set up to work on dial tone first service.

1969 article about early dtf service    http://www.telephonecollectors.info/index.php/document-repository/doc_view/11620-69oct-blr-p293-dialtone-first
1994 article about post pay and 3 slot pay phones http://www.privateline.com/issues/p.l.No.1A.html
2013 article about the national radio quiet zone (photo of post pay instruction card is the last picture)  http://www.dailymail.co.uk/news/article-2517063/Inside-The-National-Quiet-Zone-West-Virginia.html
I collect payphones :)

poplar1

This link works better for the dial tone first article in the Oct. 1969 BLR:

http://www.telephonecollectors.info/index.php/document-repository/doc_details/11620-69oct-blr-p293-dialtone-first

Most Bell System areas had "prepay" coin phones that were "coin first." On coin first phones,  there was no dial tone until a 10 cent deposit was made. There were also "postpay" coin phones (WE 193G and 212G type, for example) for many years  in areas served by Community Dial Offices; these had dial tone as soon as you picked up the receiver, and allowed calls to me made without depositing any coins. When the called party answered, the polarity of the line reversed and shorted out the transmitter and muted the receiver until 10 cents was deposited. (Automatic Electric called these "semi-postpay.")

According to the article, it was "ideally" possible to convert multi-slot phones and existing single slot coin first phones to dial tone first, and to modifiy old central office equipment. However, for economic reasons they chose not to do this when the equipment was going to be replaced soon anyway. They mentioned the new universal single slot phones that could be wired for either coin first (CF) or dial tone first.

I recall seeing a Bell tech modifying single slots in downtown Boulder, Colorado in the summer of 1977, to convert them to dial tone first.  He had actually stopped long enough to make a test call to his daughter, and then took the time to answer my questions.
Converting the existing phones included disconnecting the dial shorting contacts on the coin relay. In coin first phones, the dial was shorted until the initially deposited coin(s) opened these contacts mounted on the coin relay, when the coins reached the coin hopper.
"C'est pas une restauration, c'est une rénovation."--François Martin.

Kimball321

I have proof that at least independent telephone companies modified 3 slot pay phones for dial tone first service http://www.mvtelonline.com/items/Paystations/NE%201236  look at the photo of the instruction card and notice that calls to the operator, repair service, and 411 do not require a coin deposit.

Here is another one, and this one is Western Electric so probably used by the Bell System
http://www.mvtelonline.com/items/Paystations/WE%20234G%20Green
I collect payphones :)

poplar1

Quote from: poplar1 on September 17, 2014, 11:15:06 AM
You're right about the WE 234G phone. The instruction card indicates TSPS and DTF, along with a 3-73 date. TSPS refers to the new operator consoles that allowed long distance calls to be dialed by the pay phone user. However, a similar card on the NE 1236G set, also with area code 312, is most likely not original to the set since it appears to be a Bell System card.

Many independent phone companies were already using semi-postpay phones. Since these allowed calls to be dialed without first depositing coin(s), they could be used in emergencies, unlike the coin-first prepay sets. Semi-postpay also required much less equipment in the central office.

So two of the "improvements" Bell claimed for their DTF phones--no coins needed in an emergency, and dial tone indicating a working phone--had already existed for many years in Automatic Electric semi-postpay (=WE postpay) paystations.
"C'est pas une restauration, c'est une rénovation."--François Martin.

AdamAnt316

Thanks for the replies! It makes sense that post-pay stuck around a lot longer than pre-pay, given that it was simpler to implement and gave the same basic benefits as dial-tone first. Also makes sense that some three-slot phones stayed in service in independent/post-pay areas, and it's interesting that at least a few of them were converted to DTF (though I'm guessing they weren't in service too long in that form). Did the use of DTF and/or TSPS necessitate the use of tones for coin detection rather than the old bell and gong?
-Adam

mentalstampede

Weren't most of the Automatic Electric 3-slot pre-pays DTF already? My brother has an LPB-82 with a number of original mid 1970s instruction cards that indicate the phone was in service as a dialtone first.
My name is Kenn, and I like telephones.

"Progress isn't made by early risers. It's made by lazy men trying to find easier ways to do something." --Robert Heinlein

shortrackskater

I'd love it if someone could answer this 3 1/2 year old question!
Mark J.

Stan S

Folks
Some of you are confusing HEARING a dial tone when you take the payphone off-hook with Dial Tone First. You are mixing apples and potatoes.

EVERY AUTOMATIC ELECTRIC 3-slot (regardless of the type of payphone service it was made for) gave you a dial tone when you took the handset off the hook. Even when a call was 5 cents. On AEs certain types of service allowed you to dial a number. However, you couldn't carry on a conversation until you put the initial deposit in the payphone. Other types of service on AEs gave you a dial tone but disabled the dial until you made the initial deposit. What good is a dial tone if you can't dial anything or carry on a conversation? THAT IS NOT DIAL TONE FIRST SERVICE!

'Dial Tone First on Prepay Western 233Gs required more modification of the CENTRAL OFFICE equipment than it did modification of the payphones. Making a Western 233G DTF only required disconnecting and taping the wires going to the 'dial shorting contacts' on the coin relay terminals #1 and #2. Then installing a diode across the A and E screws on the bottom of the coin track. That was it. Making a Northern DTF was done in exactly the same way. Probably took all of 3 minutes. Modification of the coin trunks in the CO I'm sure took a little longer!

Post pay Westerns ALSO gave you a dial tone and allowed you to dial when you took the handset off hook. However, once again you couldn't carry on a conversation until you made the initial deposit. Disabling your ability to carry on a conversation was done in a different way than on AEs but the result was the same. This was done on Westerns when a call was still 5 cents. In fact it was done on payphones that were 2-piece. Research Western Electric 163C (about 1937).

'DIAL TONE FIRST' AND HEARING A DIAL TONE WHEN YOU TAKE THE HANDSET OF A PAYPHONE OFF HOOK ARE NOT THE SAME THING!

Stan S.

shortrackskater

So in other words, DTS means a dial tone that will actually dial and complete "a" call even if it's just  0 or 411 or 911?
Mark J.

Stan S

Mark
Close.
DTF means getting a dial tone without depositing a coin and only being able to call directory assistance, operator or emergency services. Dialing anything else requires an initial deposit.
Stan S.

shortrackskater

I meant to add "without depositing coin." oops!
Got it though.
Thank you!!
Mark J.

Payphone installer

Coin First go off hook,no dial tone,deposit coin,coin deposit grounds tip side of the line you get dial tone. also known as CF or ground start line
Dial Tone First go off hook here dial tone deposit coin dial number for local,long distance and interlata calls. Coin grounds tip side of the line on depsiot.  no coins required for toll free number,0+,0-, 411,211,311,711,911 or 1-555-1212. also called DTF
Post Pay go off hook listen for dial tone dial number wait for progress tone after party answers, deposit money in some offices some calls were free also just depended on the CO equipment. Had no ability to return money. Also known as PP.