Marine Receiver 352A

The Marconi Type 352A Marine Receiver covers 15 to 20,000 meters in 13 bands. It is an Audion with a rejector circuit, coupling condenser (variable in 3 stages), reaction condenser and a tuned input circuit, feeding a "Note Magnifier" (a three-electrode or pentode valve contained in the receiver) via chocke, transformer and Milliammeter in series to the H.T. The receiver has provisions for emergency operation with a crystal detector that can be plugged into the designated sockets.

It can be used with 2, 4 or 6-volt valves as desired, but a 2-volt supply is recommended.

The 8 LW bands can be switched by a band switch, the 5 SW bands (15 - 200 m) need coil change. Tuning was helped by monitoring the anode current of the detector. The model has some improvements compared to its predecessor Type 352, e.g. for band switching.

The complete equipment consists of the Type 352A two-valve receiver, a separate heterodyne oscillator Type 357 for reception of C.W. transmission in the range of 200 to 22,000 meters, and a note filter Type 358, designed to amplify a tuned range of the AF signal.

Note: the so-called "Note Magnifier" is a part of receiver Type 352A, and not to be confused with the "Note Filter" Type 358 which is a separate unit. It's currently unknown if there were also updated versions of type 357 and 358.

In questo link sono elencati 19 modelli, di cui 17 con immagini e 7 con schemi.
Elenco delle radio e altri apparecchi della MIM, Marconi International Marine; Chelmsford Essex