Atm T3903 - UK Vintage Radio Repair and Restoration Discussion Forum

Alf · 17th Aug 2007, 5:05 pm

I'm currently restoring a pair of ATM T3903's, there's a picture of one of them here:

http://www.britishtelephones.com/atm/t3903.htm

Inside, there's an Every Ready battery, a type which I've never come across before. Does anyone know if they're still obtainable? They seem to be fully enclosed in bitumen.

Nickthedentist · 17th Aug 2007, 5:10 pm

So, these phones were still in use in 1967 then? Very interesting

Nice-looking phone too. Seems to a be a 200-series body on a standard bellset housing, with a magneto generator squashed in between!

I like the sound of the "Ministry of Power" too

Alf · 17th Aug 2007, 5:15 pm

Surprisingly, there's still a tenth of a volt in the battery, I'm not really well up on telephones, I've got them ringing each other, about to get them talking to each other now, hopefully.

Dave Moll · 17th Aug 2007, 7:37 pm

I would be very surprised if the three-volt battery was still obtainable. It looks an interesting project for creating a reproduction. I think two "D" cells (or "C" cells if Ds are too big) in series is the nearest you're going to get these days.

Ed_Dinning · 17th Aug 2007, 8:47 pm

Hi Alf, as the battery is "flameproof", I suspect it has a current limiting resistor fitted inside. This was so that, if the battery was short circuited, the energy in the spark was insufficient to ignite the gasses that were present.
It may however have been something crafty with the battery construction - anyone know the mechinism?

Ed

russell_w_b · 17th Aug 2007, 8:59 pm

Quote:

Originally Posted by Alf

I'm currently restoring a pair of ATM T3903's...

...Inside, there's an Every Ready battery, a type which I've never come across before. Does anyone know if they're still obtainable? They seem to be fully enclosed in bitumen.

I know this isn't much help, but it looks (from the dimensions) like two of those square-section field-telephone cells (used in types 'F' and 'J': 'Battery, Dry, 1.5V No:12, 6135-99-910-1135 Crompton-Parkinson, South Shields) encapsulated in bitumen.
I have two very corroded versions manufactured in 1981. Perhaps you might obtain a couple and use them together, if they're not too tall. The No:12 is 35 mm x 35mm x 95mm, and the number on the casing looks like a NATO stock number, so they might still be made.

I used to use those 3V cycle-lamp batteries in my field-telephones (the ones with the brass bulb-contact between the cells and the brass switch contact on the top, the number of which I can't be bothered to look up), then I used two 'C'-cells in a plastic holder. Not authentic, but practical!

russell_w_b · 17th Aug 2007, 9:58 pm

Quote:

Originally Posted by russell_w_b

I know this isn't much help, but it looks (from the dimensions) like two of those square-section field-telephone cells...

Thinking about it a little more, I used to have a set of intrinsically safe type -'J' 'civilian' field-telephones from Haig Pit, Whitehaven, manufactured by the British Ericcson Coy (ISTR). The battery chamber on them was identical in size to that of the 'Army' type-'J' I currently have, and from which I retrieved the No:12 cell for a peep.

I wouldn't be surprised if your intrinsically-safe battery was used for them, in which case, two No:12's should do it. I'm only saying this because it might be easier to obtain a No:12 than your intrinsically-safe bitumenised version!

Dave Moll · 17th Aug 2007, 10:30 pm

If you can't find original No12s, "batterymaker1" on this forum has produced some nice reproduction ones for my field telephones. Perhaps you could enquire whether he can help you out.

If you want to revive an existing No12, the cell inside is pretty much identical to the four inside a 996 lantern battery, though I have to admit that I have not actually tried resoldering the terminals to a new cell.

Alf · 17th Aug 2007, 11:18 pm

Thanks for the comments guys, I've decided, and already started, to remove the internal stuff and attempt a reconstruction.

Alf · 21st Aug 2007, 11:36 pm

Thought I'd show you the "before" and "after" pictures.

russell_w_b · 22nd Aug 2007, 10:30 am

Quote:

Originally Posted by Alf

Thought I'd show you the "before" and "after" pictures.

Loverly... What was the horrible white gunge around the cradles, and how did you get shot of it? Are you going to fit more appropriate dial-plate inserts? What condition were the 'innards' of the telephones in, and did you need to replace anything inside (I'm thinking of perished rubber insulation)?

Alf · 22nd Aug 2007, 12:25 pm

I'm not really sure what that white stuff was around the cradle, possibly it was due to moisture and it's reaction with brass metal under the cradle, I've really no idea.

I was told that they'd been on a shelf in a garage for the best part of forty years, and they looked like they might've been! Moving parts were immovable, seized up in fact. The insides weren't too bad, just the odd bits of wiring were decayed and needed replacing. The magneto's hadn't seized up, they were
working very well. The dialler label was just a bit of artistic licence, when I can replace them, I will.

Here's a few more pics of one of them.

Herald1360 · 25th Aug 2007, 3:58 pm

Quote:

Originally Posted by russell_w_b

.I used to use those 3V cycle-lamp batteries in my field-telephones (the ones with the brass bulb-contact between the cells and the brass switch contact on the top, the number of which I can't be bothered to look up), then I used two 'C'-cells in a plastic holder. Not authentic, but practical!

ISTR 800 was the bike lamp battery. I used them for LT batteries in the late 60s (rewired in parallel...) - they were the best value, pound for pound of any battery I think. Certainly MUCH cheaper than similarly sized AD35s!

Chris

Alf · 26th Aug 2007, 11:33 pm

Yes, I re-call the 3v, N° 800 cycle lamp battery, I'm sure that externally they would work very well, however in this case, I wanted a battery that would fit inside one of the phones, the original one fits nicely. The 800 wouldn't have fitted.

mickash · 31st Oct 2007, 3:55 am

These phones were still in use at local Derbyshire collieries in the mid 70s in the surface offices. I visited one such pit with my dad in about 1975 and remember seeing one of these phones being used. The phones were connected in parallel with the bells rung in bursts of different amounts to indicate which other phone was being rung. Any phone could be picked up and the conversation listened to (no privacy possible!!) I ended up with a couple of these phones when a local pit closed but never got round to connecting them together.

17th Aug 2007, 5:05 pm	#1
Alf Hexode Join Date: May 2005 Location: Wigan, Greater Manchester, UK. Posts: 479	Atm T3903 I'm currently restoring a pair of ATM T3903's, there's a picture of one of them here: http://www.britishtelephones.com/atm/t3903.htm Inside, there's an Every Ready battery, a type which I've never come across before. Does anyone know if they're still obtainable? They seem to be fully enclosed in bitumen. Attached Thumbnails

17th Aug 2007, 5:10 pm	#2
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,864	Re: Atm T3903 So, these phones were still in use in 1967 then? Very interesting Nice-looking phone too. Seems to a be a 200-series body on a standard bellset housing, with a magneto generator squashed in between! I like the sound of the "Ministry of Power" too

17th Aug 2007, 5:15 pm	#3
Alf Hexode Join Date: May 2005 Location: Wigan, Greater Manchester, UK. Posts: 479	Re: Atm T3903 Surprisingly, there's still a tenth of a volt in the battery, I'm not really well up on telephones, I've got them ringing each other, about to get them talking to each other now, hopefully.

17th Aug 2007, 7:37 pm	#4
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,130	Re: Atm T3903 I would be very surprised if the three-volt battery was still obtainable. It looks an interesting project for creating a reproduction. I think two "D" cells (or "C" cells if Ds are too big) in series is the nearest you're going to get these days. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

17th Aug 2007, 8:47 pm	#5
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Atm T3903 Hi Alf, as the battery is "flameproof", I suspect it has a current limiting resistor fitted inside. This was so that, if the battery was short circuited, the energy in the spark was insufficient to ignite the gasses that were present. It may however have been something crafty with the battery construction - anyone know the mechinism? Ed

17th Aug 2007, 10:30 pm	#8
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,130	Re: Atm T3903 If you can't find original No12s, "batterymaker1" on this forum has produced some nice reproduction ones for my field telephones. Perhaps you could enquire whether he can help you out. If you want to revive an existing No12, the cell inside is pretty much identical to the four inside a 996 lantern battery, though I have to admit that I have not actually tried resoldering the terminals to a new cell. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

17th Aug 2007, 11:18 pm	#9
Alf Hexode Join Date: May 2005 Location: Wigan, Greater Manchester, UK. Posts: 479	Re: Atm T3903 Thanks for the comments guys, I've decided, and already started, to remove the internal stuff and attempt a reconstruction. Attached Thumbnails

21st Aug 2007, 11:36 pm	#10
Alf Hexode Join Date: May 2005 Location: Wigan, Greater Manchester, UK. Posts: 479	Re: Atm T3903 Thought I'd show you the "before" and "after" pictures. Attached Thumbnails

22nd Aug 2007, 12:25 pm	#12
Alf Hexode Join Date: May 2005 Location: Wigan, Greater Manchester, UK. Posts: 479	Re: Atm T3903 I'm not really sure what that white stuff was around the cradle, possibly it was due to moisture and it's reaction with brass metal under the cradle, I've really no idea. I was told that they'd been on a shelf in a garage for the best part of forty years, and they looked like they might've been! Moving parts were immovable, seized up in fact. The insides weren't too bad, just the odd bits of wiring were decayed and needed replacing. The magneto's hadn't seized up, they were working very well. The dialler label was just a bit of artistic licence, when I can replace them, I will. Here's a few more pics of one of them. Attached Thumbnails

26th Aug 2007, 11:33 pm	#14
Alf Hexode Join Date: May 2005 Location: Wigan, Greater Manchester, UK. Posts: 479	Re: Atm T3903 Yes, I re-call the 3v, N° 800 cycle lamp battery, I'm sure that externally they would work very well, however in this case, I wanted a battery that would fit inside one of the phones, the original one fits nicely. The 800 wouldn't have fitted.

31st Oct 2007, 3:55 am	#15
mickash Hexode Join Date: Sep 2007 Location: Derbyshire, UK. Posts: 289	Re: Atm T3903 These phones were still in use at local Derbyshire collieries in the mid 70s in the surface offices. I visited one such pit with my dad in about 1975 and remember seeing one of these phones being used. The phones were connected in parallel with the bells rung in bursts of different amounts to indicate which other phone was being rung. Any phone could be picked up and the conversation listened to (no privacy possible!!) I ended up with a couple of these phones when a local pit closed but never got round to connecting them together.