Getting an old Bakelite telephone running again.

[Mick P]

Thanks Mick, good to know that yours is fully up and running, I hope I can do the same. It appears your Ivory phone, along with the red and green 332's are worth a hefty premium over the more common black ones like mine.
I'm swotting up on these sites now I've decided to have a go at getting it to work and there does seem to be a lot of support out there. I'll know what exact questions need to be asked when I get this initial first retrofit done.

Also, looking at the 332's most have the "twisted" fabric wire between receiver and phone, although some but few are pictured with the curly cable.
Mine has the latter and is 1954. I know the phone for certain has not been messed with as it came from my aunties house many years ago before they became sought after.
I wonder if a GPO engineer changed this or whether some sets did in fact come with the curly cable?

Thanks for your input, appreciated.

Hi Kenny

You have to remember that these phones were rented by the then GPO (now BT) and engineers would call round to the house holder about once every 3 years to check it over. If the twisted cable was frayed, then the engineer would replace it and more than likely yours was done when curly cable was used. It was only a 10 minute job and it would have looked better to most people. It's only now that we aim for the original twisted stuff which I believe is still available.

Bob - you said "I don’t consider a phone that will only receive calls to be fully up and running!"

It is not the phone that is at fault, it is the exchange being unable to handle outgoing calls. They cannot pick up the dialled pulses. It is only a matter of time before they will not handle incoming calls as well and then the telephone is useless. However I can receive calls on my 332 and receive and send out on the other three. Also if I send out on one of the other 3 and then pick up the 332, I am able to communicate by it because all 4 are on the same line. So in that sense, the phone will be still be useable long after you and I have expired our mortal coil.

Regards

Mick

 

[Pete MB&D]

http://www.rotatone.co.uk/

Pete

 

[Bob McC]

Hi Kenny

You have to remember that these phones were rented by the then GPO (now BT) and engineers would call round to the house holder about once every 3 years to check it over. If the twisted cable was frayed, then the engineer would replace it and more than likely yours was done when curly cable was used. It was only a 10 minute job and it would have looked better to most people. It's only now that we aim for the original twisted stuff which I believe is still available.

Bob - you said "I don’t consider a phone that will only receive calls to be fully up and running!"

It is not the phone that is at fault, it is the exchange being unable to handle outgoing calls. They cannot pick up the dialled pulses. It is only a matter of time before they will not handle incoming calls as well and then the telephone is useless. However I can receive calls on my 332 and receive and send out on the other three. Also if I send out on one of the other 3 and then pick up the 332, I am able to communicate by it because all 4 are on the same line. So in that sense, the phone will be still be useable long after you and I have expired our mortal coil.

Regards

Mick

Mick
No one will be using land lines within 10 years.

 

[eguth]

I was given three old BT phones in the early 1970s. I used two for a few years, then put all three into storage for 30 years. They are 1954 and 1955 models. They are engineered like Rolls Royces.

Inspiration then took hold and I decided to convert them myself to work on modern BT lines, which are pulse compatible.

There were few problems with two of the phones, and these were solved with online assistance from enthusiasts online.

On of the problems on one phone was that the whole dial slipped back and forth when dialing. I solved this with strong galvanised wired. I ran a piece of it from one portion of the dial (internally) to a fixed point on the internal chassis. No further problems.

Eventually I sold one phone on Ebay. This more than covered the cost of all conversions and then some. The purchaser was delighted.

These old phones have a lovely ringing tone. On mine there are chrome buttons that can switch off the bell.

Go for it. If you have any problems specifically, I will try to assist. I may have spec sheets and diagrams for internal wiring for your phones if you need these.

Land line phones will be around for centuries further, I predict, even if there use is only by enthusiasts.

Eguth P.S. It is a pity to replace the microphone or earpiece. Quite unnecessary in most cases. The carbon powder internally tends to clump over time. Just tap the bakelite on the voice piece and earpiece against your palm repeatedly. This should free up the carbon powder and restore the fidelity. I have only had to do this once, after I converted the phoned.

 

[kennyh]

Many thanks for that Eguth, and appreciate your kind offer of assistance if needed.

As promised a quick update to this. The kit and cable arrived to do the conversion and against all the odds we now have a 1954 Bakelite phone working perfectly in the house. So much so we've switched off the awful ringers on the modern BT phones and just have the bell on the 332 to alert us.
Over the moon and surprised how well it works although I think outgoing calls may still be made with the modern phones

Clarity is great, as I say it rings lovely and dialling out is not an issue.
I stripped all the old wires out first and cleaned all terminals and washers up with solvent.
The new cable, resistor and jumper lead were installed and the old GPO jumper bars were rearranged as per the drawing.

I needed to play with the chrome dial tone buttons and also had to clean up and play with the bell striker but all is now 100% for 3/4 of an hours work. A few pics of the main stages of the job.
A great result I honestly never expected, thanks again for all your help chaps.

 

[Sue Pertwee-Tyr]

Fortunately all parts are electrical, not electronic, so it is basically just switches and coils, plus the carbon mic (that might need some rejuvenating). The first thing to check is if your phone line still supports pulse dialing.

Surely though, the way one uses such a device is to rattle the receiver cradle until the operator comes on line, then say 'get me Kensington 386' or wherever. If that isn't going to work, there seems very little point in this exercise to me.

 

[Tony L]

By way of contrast I have just restored this:

...a 1971 model 722 GPO Trimphone! I bought it looking rather grubby and tired looking for peanuts, stripped it down, replaced the cables and mic, gave it a damn good clean and plastic polish and it looks great and works a treat! Reminds me of the phone from when I was a kid at my parents. Much to my surprise it rings out fine here, not that I'll use it for that as I've a modern cordless phone. The iconic 'bleeping' ring is present and correct!

PS I've got an allegedly mint 300 series Bakelite phone on the way too as I've always wanted one and thought I'd treat myself.

 

[lordsummit]

Brilliant, we had one of those when I was a kid. I need to come round and ring you up. I remember newspaper reports about birds imitating the sound of a trim-phone.

 

[Dowser]

Brilliant, we had one of those when I was a kid. I need to come round and ring you up. I remember newspaper reports about birds imitating the sound of a trim-phone.

Yep - a mates budgie did it, annoying little f*ck

 

[Derek Wright]

The Trimphone fluorescent dial was supposed to be radio active.
At one time many decades ago I worked at STC (Standard Telephone and Cables) the Trimphone was the standard office desk phone.

 

[Vinny]

Within the last 12 months or so, there was an interview on R4, not sure if it was the whole programme, with a person who is obsessed with 'phones. I can't remember if they had/have a museum open to the public, but they certainly knew everything and more about all 'phones, how to repair them etc., as well as rarity/monetary worth.
I have had a quick search online and unfortunately the most likely contender would be this, although it seems too recent anyway, and not available on iPlayer -

http://www.bbc.co.uk/programmes/b076wf8f

Could be worth a further search of the Beeb if you have any nagging, unanswered questions.

 

[Vinny]

The Trimphone fluorescent dial was supposed to be radio active.

Many so-called luminous/fluorescent items going back to the 70's used small glass vials of various shapes and sizes that were coated internally with zinc sulphide (a simple phosphor) and contained tritium. They gave off a dull greenish light, as characteristic of ZnS.

For night-fishing they were (perhaps still are) called Betalites. The original ones could be bought as simple match-stick-sized rods (glass tubes), but eventually they could only be sold with what the law calls secondary containment - an over-sleeve of plastic or glass.

Ancient history that all should know already, but luminous watch and clock dial markings were a mix of ZnS and a radioactive isotope for many years, certainly my father had such a wrist-watch that I remember into the 70's.

Tritium is also used as a "starter" in very many lamps, not least ceramic metal-halide. I can't remember the concentration that we used in them when I worked at a lamp factory, but it was a very few ppm or less. Going back further (now defunct technology????), but thorium was used as a lamp starter, usually as thoriated tungsten that was used as part of the lamp electrodes in discharge lamps. In both cases, the idea is that the radiation, being ionising radiation, gets the arc to strike far easier - in conventional fluorescent lamps, the same is achieved by the starter, which whacks a few kV across the lamp to get it to start.

 

[Julf]

I still have a couple of these in the "to be recommissioned" pile:

Lucent-Philips IS2630, alias "Shannon", an early attempt at "screen phone" from 20 years ago. Touchscreen, wireless keyboard, and phone line interface (it is from the days before widespread broadband, after all).

 

[Guest432]

I don’t consider a phone that will only receive calls to be fully up and running!

A father with teenage daughters may consider it a god send though

 

[Tony L]

Many so-called luminous/fluorescent items going back to the 70's used small glass vials of various shapes and sizes that were coated internally with zinc sulphide (a simple phosphor) and contained tritium. They gave off a dull greenish light, as characteristic of ZnS.

Yes, in the Trimphone there is a circular tube beneath the dial, a great take-apart site here with pictures. Apparently the radioactive chemical has a half-life of just 12 years, so my Jan 1971 model is predictably flat as a pancake now. I remember the one at my parents glowing quite brightly.

 

[wacko]

If you connect it to your gramophone it will be an earphone.

 

[linnfomaniac83]

Many so-called luminous/fluorescent items going back to the 70's used small glass vials of various shapes and sizes that were coated internally with zinc sulphide (a simple phosphor) and contained tritium. They gave off a dull greenish light, as characteristic of ZnS.

For night-fishing they were (perhaps still are) called Betalites. The original ones could be bought as simple match-stick-sized rods (glass tubes), but eventually they could only be sold with what the law calls secondary containment - an over-sleeve of plastic or glass.

Ancient history that all should know already, but luminous watch and clock dial markings were a mix of ZnS and a radioactive isotope for many years, certainly my father had such a wrist-watch that I remember into the 70's.

Tritium is also used as a "starter" in very many lamps, not least ceramic metal-halide. I can't remember the concentration that we used in them when I worked at a lamp factory, but it was a very few ppm or less. Going back further (now defunct technology????), but thorium was used as a lamp starter, usually as thoriated tungsten that was used as part of the lamp electrodes in discharge lamps. In both cases, the idea is that the radiation, being ionising radiation, gets the arc to strike far easier - in conventional fluorescent lamps, the same is achieved by the starter, which whacks a few kV across the lamp to get it to start.

Fluorescent starters just work by preheating the coils at each end of the lamp, they are wired in series with both coils and complete the circuit, heating the coils until the tube becomes ionised and can pass a current, no HV pulse involved.

 

[MikeMA]

These old GPO 200 series phones are beautiful and highly collectible:

Not mine I'm afraid, but borrowed from http://www.antiquetelephones.co.uk . They have some lovely old phones for sale.

 

[Vinny]

Fluorescent starters just work by preheating the coils at each end of the lamp, they are wired in series with both coils and complete the circuit, heating the coils until the tube becomes ionised and can pass a current, no HV pulse involved.

Not so I'm afraid - heating as you suggest is never going to ionise any gas...................................
Heating the electrodes makes them emissive (give off electrons), it ionises nothing. Once the lamp is running the arc/lamp current keeps the electrodes hot, and emissive. More accurate yet, it gets the emitter (a complex barium/calcium oxide/tungstate mixture) on the electrodes, emissive

To be far more precise, conventional fluorescent lamps actually start courtesy of cosmic rays, which is why they don't work (start), unaltered, in mines - too few cosmic rays penetrate far enough.

Using a high V to get discharge lamps to start is very common, even when using other starting aids - within the industry the term "igniter" is far more common that "starter".

I worked in lamp R&D for a little short of 10 years.

 

[Vinny]

Yes, in the Trimphone there is a circular tube beneath the dial, a great take-apart site here with pictures. Apparently the radioactive chemical has a half-life of just 12 years, so my Jan 1971 model is predictably flat as a pancake now. I remember the one at my parents glowing quite brightly.

With a 12 year half life, it should be about 1/16 (6.25%) the brightness as when new - pretty dim

I remember, way back, when every spare moment was spent fishing, friends had obtained some huge banana-shaped Betalites - the envy of all - you could see what they were doing from what seemed miles away, in pitch dark - reputedly from Ford Granada dash's....................