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Vintage Telephony and Telecomms Vintage Telephones, Telephony and Telecomms Equipment |
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16th Oct 2019, 7:11 pm | #21 |
Dekatron
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 6,130
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Re: GPO Modems
Ten out of ten.
I only noticed when I was looking at the image earlier today. The giveaway is the cutout on the right-hand side to allow the handset cord to exit with the lid closed.
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Mending is better than Ending (cf Brave New World by Aldous Huxley) |
21st Oct 2019, 2:50 pm | #22 |
Hexode
Join Date: Jan 2018
Location: Portsmouth, Hampshire, UK.
Posts: 430
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Re: GPO Modems
Seeing post number 7 reminded me of a company I worked for many many moons ago now long since defunct (Transdata Ltd). They had bought in a couple to "have a look at" if you know what I mean! They (within about 3-4 months I believe) came up with their own version namely the 307 & 307A acoustic couplers. Both very good in their own right (up to 300bd), we sold thousands of the things, mainly to the GPO! I remember testing 30-50 a day & then on Fridays sitting down with the duff ones & fixing them. I always thought the GPO one was far better built, it just looked right.
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The difference between stupidity and genius is that genius has its limits. (Einstein) |
23rd Oct 2019, 12:54 pm | #23 |
Hexode
Join Date: Apr 2019
Location: Skipton, North Yorkshire, UK.
Posts: 252
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Re: GPO Modems
I use to have a set of 2B modems, in a '62' type rack, I bought them for scrap and used them in answer mode for the original Telstar BBS back in 1981/2. I had all of the circuit diagrams at one point. I will have a look but I haven't seen them for years and years.
I still have a few of the DM424X type modems and a few others. I also have an auto answer board for the Nightingale series of devices. |