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Old 28th Jun 2019, 9:10 pm   #11
G6Tanuki
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Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Ex marine AM radio equipment.

Somewhere in the attic I've got a 1950s-era "Marlin" marine-band AM set: I think it hails from the Antipodes because the receiver-dial (it covers MW down to around 4MHz - no LW band: did they have marine DF-beacons on LW in Oz/New Zealand) has MW station-callsigns of the format 2XY or 4AB which I gather was how broadcast stations were known down there).

Receiver is a "hybrid" with three US-style Brimar 12V-HT valves in the RF stages (FC, IF amp, detector/1st-audio) coupled with an OC72 and an OC16 as the audio-output.

Transmitter is valve: vibrator-HT, two EZ81 as rectifiers, an EF80 xtal osc with six xtal-positions, a 6L6 as PA. Modulator is another 6L6 coupled to the PA by a centre-tapped choke (like the primary of a push-pull amp). it's designed, seemingly, to use a carbon mic as the grid of the modulator 6L6 is fed from the secondary of a small transformer and there's DC on one side of the mic audio-connector.

How this came to be in the UK I really don't know.
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