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Old 17th Jul 2017, 6:50 pm   #8
Dave Moll
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Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 3,149
Default Re: Telephone Set H Mk III

The handset of the Mk II may look externally similar to that of other field telephones with four-pin plugs, but the insets are very different - particularly the transmitter inset, which is similar to a receiver inset and generates a current rather than the varying resistance of a carbon-granule inset.

The handset switch of the Mk III is normally open and shorts out (as I noted earlier) a 0.8μF capacitor.

While talking about appearances, the Mk II looks externally similar to a telephone set "F" Mk I, but the insides have a lot of empty space with very little other than the magneto. The Mk III likewise externally resembles a telephone set "J", but with a similarly sparsely-populated interior.
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