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Vintage Telephony and Telecomms Vintage Telephones, Telephony and Telecomms Equipment |
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11th Jan 2016, 6:16 pm | #1 |
Rest in Peace
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,944
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GEC Battery Telephone
My best pal's father was a bit of a hoarder to say the least. When he passed away some years ago my pal had to empty a 6 x 8 shed that was stuffed floor to ceiling with what was mostly rubbish.
This GEC K7820 telephone was found although unfortunately it is missing both the transmitter and the receiver. Some information on www.britishtelephones.com. Can anyone add any info or comments? |
11th Jan 2016, 6:35 pm | #2 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,188
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Re: GEC Battery Telephone
The 4 terminals would seem to be :
ZE : Zinc and Earth -- one side of the line (Earth) and the -ve side (zinc) of the local battery L : Line -- the other side of the line. It was not uncommon for these sets to be used with one wire linking them (between the L terminals of the 2 sets) and earth return (E connected to an earth spike or similar) C : Carbon -- The +ve side of the battery for operating the signalling bells. How many cells you need depends on the line length MC : Microphone Carbon -- The +ve side of the battery for the carbon microphone circuit. Too high a voltage here will lead to 'frying noises', so it was common to run the microphone off 2 cells (about 3V) I think and have a higher voltage for the bells. The 2 cells for the microphone were also part of the bell battery. |
11th Jan 2016, 8:14 pm | #3 |
Dekatron
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 6,118
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Re: GEC Battery Telephone
With a carbon transmitter attached to the front a a "watch" receiver (so-called because it resembles a pocket watch) hung from the receiver hook, I have taken a simplistic approach and mine run very happily on a single 6V supply (using a 996 lantern battery) with "C" an "MC" strapped together.
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