"Plan-set" GPO 706 black (and now also in Ivory)!

[gpo706]

Its nicer than my black, but I think I will leave it at moment, I just need a grey set now!

[gpo706]

I passed on the grey set, (which went for a fiver) as these have been coming on like a rash of late, there's even another ivory on the bay, here's the seller's pics (oblique angles).

This one has been rewired for a 4 core BT PST plug, so I emailed the seller asking for some advice, fingers crossed!

[gpo706]

Tribune - I was de-mucking my room today and had a stack of cardboard boxes (for phone deliveries), and emptied the bubblewrap/paper etc.

Went to bed and awoke with something in the small of my back.

It's a 706 black blanking button!

Moral of the story - be very thorough when unpacking boxes.

BTW the seller of the set above e-mailed me back to say he hadn't a clue as to how it was wired to a 4 core cord, nice chap for him to even reply.

[gpo706]

Hey - I just had another look at the Ivory set, on the base is a sticker saying "BT Museum Norwich", and written on the label the number 69.

So at last I have a genuine museum piece!

I can't find anything much on the www about the late museum, I guess it closed and they sold the exhibits off.

http://strowger-net.telefoonmuseum.com/tel_info_museums.html

"NORWICH TELECOM MUSEUM. Closed but planned to re-open under volunteer management."

[Phonesrfun]

That is quite a lengthy list, and there are at least three (2 US and 1 Canadian) that are not on the list.

[GG]

Yo GPO706-

Very interesting and good finds there.  Those keysets look very mechanically complex compared to the way we do things in the US, where the telephone set (e.g. WE type 564 or 565) is relatively simple, and is connected to a Key Service Unit (KSU) that is more complex and requires AC mains power even for the bells to ring in many cases.   What the GPO seems to have done with these units is put all the complexity in the base of the "master" phone and use simpler phones (706s with a buzzer and a pressbutton added) as the "sub" stations. 

Also have you noticed that the arrangement of functions on these is identical to that on the variant of the type 232 mounted on Bellset 39, per here:  http://britishtelephones.com/bellst39.htm

If you can't get them to work right away, I'd suggest just hanging on and waiting until a schematic turns up, as it will do eventually, rather than attempting to modify these sets. 

So I have a question:  Do you know what types of installations these were intended for?   

My guess is something along the lines of "secretary & chiefs," where a secretary is answering calls for two executives; also in shops where the shopkeeper has an office in back and there might be a phone at the front counter and some other location.  In general any situation where one person primarily is answering the outside calls, and two others are conducting other types of business that don't entail constant use of the phone. 

In the US we typically dealt with those situations by having similar multi-line phones at each location, but setting up the system to ring only at the secretary's desk or in the shopkeeper's office.  This would make it easier for the other stations to answer calls that they heard ringing in the other room (the secretary or shopkeeper wouldn't have to press a button to enable other stations to ring), but at the expense of added complexity all'round.  BTW, I installed countless 1A2 systems of this type, back in the day.  So if you have questions, ask away. 

One more question: do you know if GPO ever issued the HES No.2 in light gray?  I have a PMG (Australian) version in light gray, which arrived rather smashed up a few years ago (bad shipping) but I've repaired the damage, and one of these days will try to get it working in some way.  Though, the line cord was also cut off (which I knew before I got this unit), so I might have to make do by using a US 25-pair cable with 25-pair connector at the end. 

Thanks -
-G.

[Owain]

I'm surmising from what I read here:

http://www.britishtelephones.com/plans625.htm

and here:

http://www.britishtelephones.com/gec/plansets.htm#105

That it needs only to be correctly wired up to 2 other phones, and acts as a "master-station", the fat cable I assume is off 3 x 4 core for the comms and another 2 core for 12V DC to power the lamps etc.

It's slightly more complicated than that. 

Bear in mind that in the British system bells are (were) 2x500ohm in the phone and the bells were wired in series. When the line is EXTN-EXCH the extension bells are in series with the bells in the Main.

As well as calling the Main, on a 2-extension system there was also the facility for each Extn to buzz the other without the intervention of the main.

There was also the facility to extend earth recall from the Main and the Extns to a PABX.

Diagrams are linked from here eg here

[Owain]

So I have a question:  Do you know what types of installations these were intended for?   

My guess is something along the lines of "secretary & chiefs," where a secretary is answering calls for two executives; also in shops where the shopkeeper has an office in back and there might be a phone at the front counter and some other location. 

They were extensively used for boss/secretary working, either off a direct exchange line or for filtering calls from a PBX extension.

The extensions could also be external (2-wire + earth) and would be used for eg extending calls from a doctor's surgery to the house after hours.

Many small businesses would only have had one phone line anyway. Or the boss would have had a direct exchange line to another phone on his desk for private/outgoing calls.

[GG]

Owain, now that is majorly cool: off-premise extensions from a doctor's surgery (US: doctor's office) to his house.  I had heard of something like that with the HES systems but I thought they used a magneto to ring the off-prem extensions' bells.   

Off-premise extensions in the US are relatively rare (though now they can be done more easily with VOIP phones, and I say that as someone who is not a bandwagon-jumper for VOIP).  The reason probably is that in the US, people tend to live at relatively large distances from where they work (and spend much time driving back & forth), whereas in most of the rest of the world, people live closer to their workplaces.  So the telcos in the US didn't spend a lot of time developing OPX equipment.  One exception was a transfer relay developed by AE that would be installed in a rack in the CO, and actuated by a turn-key in the telephone: this would transfer the CO line to a different location, from within the CO.  I have to assume that was relatively expensive. 

The idea that it could be done by looping the OPX through a telephone set is very cool in that it suggests the entire lifestyle & culture whereby one's home might be within a couple of miles' distance of one's office.  Presumably the secretary would stay a little later, and the doctor would ring the secretary on intercom to say "Hi, I'm at home now, please transfer the line." 

Contrast to the complexity we deal with today, for doctors' office PBXs, involving after-hours pagers and cellphones, VOIP extensions, caller-selectable transfer to the answering service or to the pager, etc. etc.  And of course doctors do not usually have office extensions in their homes because they already work 60-hour weeks as it is.   OTOH, nurses sometimes do: I have a few nurses with VOIP phones at home, and they can press a button on those phones to enable them to ring for office calls.  Hmm.... : - )

Which reminds me, I should be programming a voicemail system right now for one of those clients.  See y'all later...

[Owain]

Owain, now that is majorly cool: off-premise extensions from a doctor's surgery (US: doctor's office) to his house.  I had heard of something like that with the HES systems but I thought they used a magneto to ring the off-prem extensions' bells.   

AC ringing generator (convertor ringing) in the power unit (and some extra relays of course) in the HES 3 and 4. Probably a magneto in HES 1 and 2.

Off-premise extensions in the US are relatively rare .....One exception was a transfer relay developed by AE that would be installed in a rack in the CO, and actuated by a turn-key in the telephone: this would transfer the CO line to a different location, from within the CO.  I have to assume that was relatively expensive. 

At one point we had subscriber-controlled transfer also. However what we had far fewer of (if any) was off-premise answering services

The idea that it could be done by looping the OPX through a telephone set is very cool in that it suggests the entire lifestyle & culture whereby one's home might be within a couple of miles' distance of one's office.  Presumably the secretary would stay a little later, and the doctor would ring the secretary on intercom to say "Hi, I'm at home now, please transfer the line." 

The doctor could also go home for lunch but still receive urgent calls.