MK. XV A.P 13231 British Admiralty Sound phone (Help needed please) - UK Vintage Radio Repair and Restoration Discussion Forum

T.S1997 · 28th Sep 2016, 10:56 pm

Hello everyone. My name is Tim, and I'm new here. I signed up because I need help with a pair of the above phone, made by the Tele.mfg.Co in London. From the research I have done, they were used in the second World War by the British navy for communicating between cabins or even from the bridge to the engine room etc. Now, my problem is that I have them both wired up together, and although they ring each other fine, if I try and talk through the one it doesn't come through on the other handset (and vice versa).

My question is, does anyone on here have any kind of wiring diagram for this type of phone? Or would someone possibly be able to look at one of their phones and tell me where all the wires are going to?

Many thanks, and thanks for having me on board here,

Tim

(Note to admin: If I have posted this in the wrong place, then please feel free to move it to the correct board or delete if necessary. Thank you)

BigClick · 29th Sep 2016, 1:16 pm

Hi, have you tried here.... http://www.britishtelephones.com/adm...admiralty1.htm

T.S1997 · 29th Sep 2016, 2:57 pm

Hi there, that was the first website I found with anything to do with my type of phone. But, all there is on there is information on what the phone was used for and who used it.

Tim

TonyDuell · 29th Sep 2016, 5:25 pm

I have a similar telephone (just one) here.

The handset contains 2 transducers,wired in parallel I think. There are 2 wires in the handset cable. You just link the 2 handsets (one on each telephone) electrically in parallel, speaking into one of them will cause the mouthpiece transducer there to produce enough voltage to be heard in the earpiece transducers (hence the name 'sound powered').

I believe the 2 telephones needed 3 wires to interconnect them, common, calling, and speech. The terminals are labelled 'C' for common, 'M' for calling and 'L' for speech. You just connect similar letters together in the 2 telephones.

dagskarlsen · 29th Sep 2016, 6:05 pm

I hope this scan may help you.
dsk

TonyDuell · 29th Sep 2016, 7:03 pm

I find it curious that the iron/steel case of the model 15 might affect the compass (hence the 15*) but that the magneto generator did not have enough stray field to do so.

Incidentally, as those diagrams imply, the magneto in these telephones is a relatively low voltage but higher freqeuncy (audio frequency) one. It directly operates a transducer in the case of the called telephone causing the signalling tone and is stepped up by a transformer to operate the neon bulb.

dagskarlsen · 29th Sep 2016, 8:39 pm

This is a totally other phone, but this diagram may also work.
(page 78 of 109)
http://radionerds.com/images/2/22/TM_11-5805-243-13.PDF

dsk

T.S1997 · 30th Sep 2016, 2:40 am

Quote:

Originally Posted by TonyDuell

I believe the 2 telephones needed 3 wires to interconnect them, common, calling, and speech. The terminals are labelled 'C' for common, 'M' for calling and 'L' for speech. You just connect similar letters together in the 2 telephones.

Right, okay, I see where you're getting at there. I have seen those three letters attached to various terminals inside the phone. I'm assuming there's more than one set of terminals so that more than two phones can be wired together? And for testing purposes at the moment I have a length of twin core cable that came off of a lawnmower (I think

). I will find some twin core + earth and retest.

Tim

TonyDuell · 30th Sep 2016, 6:58 pm

You could try disconnecting the handset leads (there will be 2) inside each 'phone (make a diagram so you can put them back in the right places later) and then connecting the 2 handsets in parallel using the 2-core cable you have. This should allow you to talk between the handsets (obviously without ringing). If not then you have problem with the handset cable or the transducers in the handsets.

T.S1997 · 15th Nov 2016, 11:10 pm

I tried this, but to no avail

TonyDuell · 16th Nov 2016, 7:02 am

You need to determine if the fault is electrical or mechanical, I think.

Disconnect each handset. Measure the resistance between its 2 wires. Do you get a non-infinite reading which is roughly the same in both cases?

Do the 2 wires of the interconnecting cable show infinite resistance between them (handsets disconnected)? Does that drop to a low reading if you short the wires at the 'far end' of the cable?

It is possible to dismantle the transducers used in these handsets if necessary, but you need small tools (you may have make a spanner by filing a bit of metal strip (!)) and a lot of care.

28th Sep 2016, 10:56 pm	#1
T.S1997 Retired Dormant Member Join Date: Sep 2016 Location: Birmingham, UK. Posts: 4	MK. XV A.P 13231 British Admiralty Sound phone (Help needed please) Hello everyone. My name is Tim, and I'm new here. I signed up because I need help with a pair of the above phone, made by the Tele.mfg.Co in London. From the research I have done, they were used in the second World War by the British navy for communicating between cabins or even from the bridge to the engine room etc. Now, my problem is that I have them both wired up together, and although they ring each other fine, if I try and talk through the one it doesn't come through on the other handset (and vice versa). My question is, does anyone on here have any kind of wiring diagram for this type of phone? Or would someone possibly be able to look at one of their phones and tell me where all the wires are going to? Many thanks, and thanks for having me on board here, Tim (Note to admin: If I have posted this in the wrong place, then please feel free to move it to the correct board or delete if necessary. Thank you)

29th Sep 2016, 1:16 pm	#2
BigClick Hexode Join Date: Dec 2015 Location: Walsall, West Midlands, UK. Posts: 327	Re: MK. XV A.P 13231 British Admiralty Sound phone (Help needed please) Hi, have you tried here.... http://www.britishtelephones.com/adm...admiralty1.htm

29th Sep 2016, 2:57 pm	#3
T.S1997 Retired Dormant Member Join Date: Sep 2016 Location: Birmingham, UK. Posts: 4	Re: MK. XV A.P 13231 British Admiralty Sound phone (Help needed please) Hi there, that was the first website I found with anything to do with my type of phone. But, all there is on there is information on what the phone was used for and who used it. Tim

29th Sep 2016, 5:25 pm	#4
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: MK. XV A.P 13231 British Admiralty Sound phone (Help needed please) I have a similar telephone (just one) here. The handset contains 2 transducers,wired in parallel I think. There are 2 wires in the handset cable. You just link the 2 handsets (one on each telephone) electrically in parallel, speaking into one of them will cause the mouthpiece transducer there to produce enough voltage to be heard in the earpiece transducers (hence the name 'sound powered'). I believe the 2 telephones needed 3 wires to interconnect them, common, calling, and speech. The terminals are labelled 'C' for common, 'M' for calling and 'L' for speech. You just connect similar letters together in the 2 telephones.

29th Sep 2016, 6:05 pm	#5
dagskarlsen Heptode Join Date: Jan 2008 Location: Hakadal, Norway Posts: 643	Re: MK. XV A.P 13231 British Admiralty Sound phone (Help needed please) I hope this scan may help you. dsk Attached Thumbnails

29th Sep 2016, 7:03 pm	#6
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: MK. XV A.P 13231 British Admiralty Sound phone (Help needed please) I find it curious that the iron/steel case of the model 15 might affect the compass (hence the 15*) but that the magneto generator did not have enough stray field to do so. Incidentally, as those diagrams imply, the magneto in these telephones is a relatively low voltage but higher freqeuncy (audio frequency) one. It directly operates a transducer in the case of the called telephone causing the signalling tone and is stepped up by a transformer to operate the neon bulb.

29th Sep 2016, 8:39 pm	#7
dagskarlsen Heptode Join Date: Jan 2008 Location: Hakadal, Norway Posts: 643	Re: MK. XV A.P 13231 British Admiralty Sound phone (Help needed please) This is a totally other phone, but this diagram may also work. (page 78 of 109) http://radionerds.com/images/2/22/TM_11-5805-243-13.PDF dsk

30th Sep 2016, 6:58 pm	#9
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: MK. XV A.P 13231 British Admiralty Sound phone (Help needed please) You could try disconnecting the handset leads (there will be 2) inside each 'phone (make a diagram so you can put them back in the right places later) and then connecting the 2 handsets in parallel using the 2-core cable you have. This should allow you to talk between the handsets (obviously without ringing). If not then you have problem with the handset cable or the transducers in the handsets.

15th Nov 2016, 11:10 pm	#10
T.S1997 Retired Dormant Member Join Date: Sep 2016 Location: Birmingham, UK. Posts: 4	Re: MK. XV A.P 13231 British Admiralty Sound phone (Help needed please) I tried this, but to no avail

16th Nov 2016, 7:02 am	#11
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: MK. XV A.P 13231 British Admiralty Sound phone (Help needed please) You need to determine if the fault is electrical or mechanical, I think. Disconnect each handset. Measure the resistance between its 2 wires. Do you get a non-infinite reading which is roughly the same in both cases? Do the 2 wires of the interconnecting cable show infinite resistance between them (handsets disconnected)? Does that drop to a low reading if you short the wires at the 'far end' of the cable? It is possible to dismantle the transducers used in these handsets if necessary, but you need small tools (you may have make a spanner by filing a bit of metal strip (!)) and a lot of care.