Unknown receiver from Detrola

Recently I found this quite unusual radio receiver from Detrola, USA. It is a single band superheterodyne covering from 200 to 400KHz. Its IF is around 145KHz. The circuit uses the following tubes:

6K7GT    RF amplifier
6SA7GT    Frequency converter
6SK7GT    IF amplifier
6SQ7GT    Detector and audio preamplifier
28D7GT    Audio amplifier

26.5 VDC single supply voltage, both for tube heaters and for anode supply.

It is very compact, measuring 106mm high, by 106mm wide, by 138mm deep, plus 25mm for the supply filter on the rear (4,17 by 4,17 by 5,43 inches). The tuning knob drives the three sections variable capacitor through one 8 to 1 coaxial drive.

The receiver was probably intended for aircraft and boat navigation purpose, to receive four-course low-frequency range signals, widely used well after WWII.

Unfortunately there is no indication of the model type or of the production date: does somebody knows more about? 

Regards,

Emilio Ciardiello

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Dear Emilio,

In the early 1940s the USA navy fliers and air force set up a Ferry Command to move aircraft and supplies around the world.    Special navigation posts were set up in such places as Alaska and Greenland to aid the polar flights to try to avoid interception.

Temporary receivers were installed in aircraft to receive these long-range beacons. 

I have no details of this particular receiver, but the legend and frequency range makes it clear that this is one such device.

Best regards,

Roy 

 

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