1980's telephone system

[grahame1]

Hi there. I'm not a telephone engineer. But I am just enquiring as to whether there are any engineers here who worked on or are familiar with the mechanical telephone systems of the mid 1980's?
I have a couple of questions I would like to put to anyone who has the ability to answer.

Can I suggest you post the questions, and then you may (or may not) get answers to them.

[grahame1]

Originally Posted by Hugh

Can I suggest you post the questions, and then you may (or may not) get answers to them.

Ok. re the mid 1980's telephones: (1) If someone phones someone else and the person on the receiving end does not answer, how long would the ringing last before it would be cut off by the system? Would it ring for as long as the person held the phone. Or was there a cut off point?
(2) If there was a telephone conversation going on and one of the parties hung up, could a telephone engineer tell which party hung up first?

I hope my questions are clear enough to be understood?

By mechanical, do you mean strowger, or crossbar, or even TXE (which used mechanical reed switches)
(Strowger would not normally cut you off ringing, TXE usually would).

The answer to (2) is gererally no (unless they were monitoring with some fancy equipment).


Im curious why you would want to know this ?

[cookie_365]

I'm guessing researching a novel set in the 80s?

[grahame1]

Originally Posted by Paul M

By mechanical, do you mean strowger, or crossbar, or even TXE (which used mechanical reed switches)
(Strowger would not normally cut you off ringing, TXE usually would).

The answer to (2) is gererally no (unless they were monitoring with some fancy equipment).


Im curious why you would want to know this ?

Hi there thanks for your answer. I wish I knew the difference between strowger or crossbar.
The exchange was in Maldon in Essex and the year was 1985. A crime was committed at a certain house and someone said that the criminal telephoned his own phone from the place the crime was committed and then left the receiver off the hook. Then he cycled home to his place, picked up his own phone and then hung up to make it look as if the person was at home in the place he robbed and that he even telephoned him. This was to give himself an alibi.
So you see the reasons for my questions? I just wondered if an ordinary telephone engineer could tell who hung up on who? As he said in court that the criminal was the one who hung up his own phone instead of the man who was robbed? The robber said to the police that the line went dead as if someone have put their finger on the button.
So that's why I asked if it were possible to tell who hung up on who?
The other question of course is the vital one, as it would have taken the robber 20 minutes to cycle home. I just wondered if the phone would continue ringing for that length of time? One person told me that there was a cut off point of 6 minutes?

---------- Post added at 22:05 ---------- Previous post was at 22:00 ----------

Originally Posted by cookie_365

I'm guessing researching a novel set in the 80s?

You are nearly on the button there. It was a crime that was committed in the 80s.

[progers]

I worked on strower exchanges but I can't remember the timeout on ring tone.

The only way the engineer could tell who hung up first was if he was pre- warned and actually in the exchange so he could connect into the call

[grahame1]

Originally Posted by progers

I worked on strower exchanges but I can't remember the timeout on ring tone.

The only way the engineer could tell who hung up first was if he was pre- warned and actually in the exchange so he could connect into the call

Thank you for that information. That is very useful.

[cookie_365]

Well, if this event really happened, which of course it didn't, at least the burglar renounced his life of crime and took up a new, legitimate career as a scriptwriter on Jonathan Creek

[grahame1]

Originally Posted by cookie_365

Well, if this event really happened, which of course it didn't, at least the burglar renounced his life of crime and took up a new, legitimate career as a scriptwriter on Jonathan Creek

It did actually happen. I've just changed a couple of details and left out names. It was a multiple murder that took place near Maldon in essex in 1985.

Just one more question if I may? If the murderer was trying to give himself an alibi was there any way that engineers could tell at what time the phone call was made?
I know they seem like stupid questions. But someone suggested this scenario and I' trying to prove that such a thing was not possible.

---------- Post added at 09:27 ---------- Previous post was at 08:33 ----------

Originally Posted by grahame1

It did actually happen. I've just changed a couple of details and left out names. It was a multiple murder that took place near Maldon in essex in 1985.

Just one more question if I may? If the murderer was trying to give himself an alibi was there any way that engineers could tell at what time the phone call was made?
I know they seem like stupid questions. But someone suggested this scenario and I' trying to prove that such a thing was not possible.

You know, I forgot the most important questions of all.
(1) Could an engineer tell if a call was in fact made that morning?
(2) Could they tell the duration of that call?

There must have been some way of recording the time of the call in order for the customer to be billed? Or did they work out the bill in some other way in 1985?

IIRC you got a meter reading, in units, at the end of each quarter. Itemised bills came with the digital exchanges.

[grahame1]

Originally Posted by Chris

IIRC you got a meter reading, in units, at the end of each quarter. Itemised bills came with the digital exchanges.

So do the units represent minutes?

You're taxing my memory now. I can't remember if the price of a unit changed by time of day, or if the length of time you got for a unit did. Perhaps someone older will remember, I didn't get my own phone bill until a few years after the 80s were over and done with.

Originally Posted by grahame1

You know, I forgot the most important questions of all.
(1) Could an engineer tell if a call was in fact made that morning?
(2) Could they tell the duration of that call?

No & No.

There was no system to record such things on old strowger exchanges.
Call metering was done once a call was answered, simply by sending meter pulses at regular intevals to a customers meter (every number had its own meter).

Just out of interest, are you sure the exchange in question was infact not an electronic exchange ?
In 1985 many exchanges were not electro-mechanical (strowger) exchanges, there were Crossbar, TXE2, TXE4 and even some early System X (digital) exchanges around.

---------- Post added at 17:41 ---------- Previous post was at 17:38 ----------

Originally Posted by grahame1

So do the units represent minutes?

No. They were just "units". Units were clocked up at a faster rate at peak times.

[joglynne]

I can't track down any information regarding the Maldon Phone Exchange but the Colchester exchange had electronicequipment installed in 1985. It is possible that any call made to Goldhanger from the family home in Maldon may have been routed through that exchange?

http://www.british-history.ac.uk/rep...ompid=21992#s6