Hi,

Am I right in thinking crossbar exchanges, say circa 1985 were strowger or
would these have been some osrt of electronic exchange, i.e. txe2 ??
Portslade was the one in mind.

And if im on the right track, didn't they have a different ringing cadence
something to do with PBX's grabbing the line to soon?

Thanks.

"Pigeon"  wrote in message
news:EKudnRI3z-pxKU_VnZ2dnUVZ8vmdnZ2d@posted.plusnet...

> Hi,
>
> Am I right in thinking crossbar exchanges, say circa 1985 were strowger or
> would these have been some osrt of electronic exchange, i.e. txe2 ??
> Portslade was the one in mind.
>
> And if im on the right track, didn't they have a different ringing cadence
> something to do with PBX's grabbing the line to soon?
>
> Thanks.

Sorry I think I meanr TXE4 not TXE2 !!!

On Thu, 18 Sep 2008 21:07:26 +0100, "Pigeon"  wrote:

>Am I right in thinking crossbar exchanges, say circa 1985 were strowger or
>would these have been some osrt of electronic exchange, i.e. txe2 ??
>Portslade was the one in mind.

Crossbars were an electro-magnetic system using relays and Crossbar
switches.  They were somewhat similar to TXE(2 or 4) in that they were
common control (as opposed to the step-by-step Strowger system).

>And if im on the right track, didn't they have a different ringing cadence
>something to do with PBX's grabbing the line to soon?

They had an extra burst of continuous ringing at the start of the call,
before the normal ringing cadence started, which was just to give the
impression that a call was connected immediately. 

Initially this was both ringing tone (to the caller) and ringing current
(to the callee), but the ringing current part was removed when problems
started arising because of PBXs answering on this initial burst of
ringing.  

-- 
Ian

The from address is valid

Pigeon wrote:
> Hi,
> 
> Am I right in thinking crossbar exchanges, say circa 1985 were strowger or
> would these have been some osrt of electronic exchange, i.e. txe2 ??
> Portslade was the one in mind.
> 
> And if im on the right track, didn't they have a different ringing cadence
> something to do with PBX's grabbing the line to soon?
> 
> Thanks.
> 
> 

They were crossbar, that is neither strowger or electronic.
You might be thinking of the pre-ring that was sent out by some before 
the normal ringing.

-- 
Tony the Dragon

Pigeon wrote:
> "Pigeon"  wrote in message
> news:EKudnRI3z-pxKU_VnZ2dnUVZ8vmdnZ2d@posted.plusnet...
> 
>> Hi,
>>
>> Am I right in thinking crossbar exchanges, say circa 1985 were strowger or
>> would these have been some osrt of electronic exchange, i.e. txe2 ??
>> Portslade was the one in mind.
>>
>> And if im on the right track, didn't they have a different ringing cadence
>> something to do with PBX's grabbing the line to soon?
>>
>> Thanks.
> 
> Sorry I think I meanr TXE4 not TXE2 !!!
> 
> 
> 
The xbar exchanges were TXK's

-- 
Tony the Dragon

"Pigeon"  wrote in message 
news:EKudnRI3z-pxKU_VnZ2dnUVZ8vmdnZ2d@posted.plusnet...
> Hi,
>
> Am I right in thinking crossbar exchanges, say circa 1985 were strowger or
> would these have been some osrt of electronic exchange, i.e. txe2 ??
> Portslade was the one in mind.
>
> And if im on the right track, didn't they have a different ringing cadence
> something to do with PBX's grabbing the line to soon?
>
> Thanks.
>
>

Strowger exchanges 19th Century to ~1960

Crossbar - gradual takeover to 1979

1979 on (in UK) - electronic System X exchanges installed..  Essential 
complete by mid 1990's.

Despite a 40 year projected life for SX (to 2019) BT are now installing 21CN 
exchanges.

Crossbar exchanges have a long first ring, although I am afraid I can't 
remember why.

Pigeon wrote:
> Hi,
> 
> Am I right in thinking crossbar exchange 

[snip]

discussion between two angry sheep?

Allan
(Sorry: poets' day...?)