Quote:
Originally Posted by arjoll
Quote:
Originally Posted by Nickthedentist
Quote:
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Multi-party ringing. A small and rapidly decreasing proportion of rural lines connected to the Telecom PSTN are multi-party and use a system of code ringing based on the morse code. This type of line is being progressively phased out by Telecom and replaced by individual lines.
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Anyone care to elaborate? |
Party lines. On manual exchanges you'd have a number like "123S" and the ring would be an "S" in morse. If you were "123M" you wouldn't answer - unless you were nosy. With automatic exchanges you'd have a normal looking number, but the distinctive ring and shared line remained.
It was only in remote areas - for example my wife grew up in Monowai and they had a party line until the late 80s, on an automatic exchange by that stage and it would have been one of the last areas. The last couple of manual exchanges were gone by then too - funnily enough Queenstown was one of the last.
As far as I'm aware our phone system shouldn't be significantly different to the UKs - <snip> |
A lot of the earlier 'Strowger kit was supplied from the UK by the likes of Ericssons & GEC. I have a number of NZPO telephones from 'multi-party' party lines. There were two sorts of party lines. Ones which used 'Simplex Dialling' are the ones I've got. They have both a dial and a magneto generator. They are 'local battery telephones and there would be up to 5 connected across the same line/pair of wires. The Simplex dialling (also used in Saskatchewan in Canada) was an unusual form of dialling. The caller would lift handset and listen and if the line wasn't in use, they would press the 'Call' button which locked in until the handset was replaced. The Call button connected one side of the dial pulsing contacts to earth whilst the other side of the pulsing contact was connected to the centre tap of the AC bell coils. The bell was connected (without a capacitor) across the A and B line wires. It then operated a high speed relay also at a centre tapped point. Caller could then dial out into the rest of the network. As mentioned , incoming calls from the PSTN sent the relevant ring code according to the Morse letter allocated to the called line. Callers on the same multi-party line called each other with a generator using the same Morse code letters.
The other type of party line was a 5 party 'revertive call' line where the caller would dial the code of the required 'party phone' then replace the handset. It used loop dialling rather than the earth 'Simplex' dialling. All the phones would then ring with the relevant code ring. When the person whose code it was answered, the ringing would stop and the caller would lift the phone and they could speak. WE have managed to get the 'multi-party' party line with the S/A/D/M or R code ringing working on CNet with up to five telephones working on an ATA - only works with Linksys ATAs. Luckily I've got hundreds of NZPO circuit diagrams for their Strowger exchanges including the NZ version of the GPO's UAX13.