New toy! GEC Alphalink
This is my new toy. It’s a GEC Alphalink, and it’s a telephone exchange (local PABX) – it supports loop disconnect dialing only (none of your modern DTMF nonsense) and contains somewhere in the region of 30 relays. Lets take the lid off…
There are two boards, a main board which has all the control gubbins and connectors for the two incomming exchange lines and the first 4 of the extension lines. There’s a daughter board which hosts the other 4 extension lines. It’s missing a relay, so let’s take it off and give both boards a once over to make sure they look alright and there are no blackened components near the powersupply. (The wiring in my house is a bit suspect, so I like to check second hand stuff by eye before plugging it in!)
Both boards off you can see all the lovely orange relays (these are for connecting lines to the internal voice paths – of which there are two – hence two orange relays per line) The smaller white relays apply the ringing signal to a the line. One of these is missing from the daughter board, and one on the main board is missing it’s lid. I think I know where I can get replacements though.
Lets put it back together and see what it does!
Well, it works, and here it is with a green trimphone on the left and a pulse dialing push-button phone on the right.
All lines (apart from the one with the missing relay) seem to do the right thing. It still doesn’t have the UK ringing cadence so it’s not perfect – but I’m very happy with it! I hooked up one of its exchange lines to my Opera 206 (a smaller, more modern exchange) and that seems to work too.
The next job is to replace the missing and damaged relays, install it, cable up my house, and find myself some way of going from pulse dial->VOIP so I can make internet phonecalls from my phone collection.
Edit: I almost forgot. Mr Stubbs wanted a picture of the wacky “bent wire and hooks” DIP switch arrangement which is used for programming the system. None of your fancy systemphones here thankyouverymuch.
Super!
Assuming you dial a number from any extension to get an outside line then putting a Pulse to Tone converter on the exchange side of your PABX might work. Once you have the outside line it should be able to convert the loop disconnect to DTMF (but don’t expect * or # functionality like the internally fitted rototone module). I get the impression you are living in the colonies so you might like to try here first…
http://www.oldphoneworks.com/antique-phone-parts/parts-and-pieces/pulse-to-tone-converters/
Hi Nick, I’m not sure what gave you the impression I was a colonial (I’m in good old Blighty!) but that oldphoneworks site looks interesting anyway. I keep meaning to ask http://www.telephonelines.net if they stock any pulse to tone converters as they’re only a couple of junctions up the motorway from me.
My current thinking is that I may be able to persuade my Opera 206 exchange to accept LD on the extensions, but convert it to DTMF as it goes out the exchange lines. I can then use that as a gateway for the alphalink, essentially using it as a pulse to tone converter. I’ve also got a DTMF keyfob generator thing which I can use if I need a * or #
Of course, getting round to putting it all together is probably more of a challenge than the actual technical side of things!