• Country
• United States of America (USA)

• Manufacturer / Brand
• Detrola; Detroit (MI)

• Year
• 1941 ?

• Category
• Military Receiver

• Radiomuseum.org ID
• 194399

Click on the schematic thumbnail to request the schematic as a free document.

Audio (to hear)

• Number of Tubes
• 5

• Valves / Tubes
• 6K7 6SA7 6SK7 6SQ7 28D7

• Main principle
• Superhet with RF-stage; ZF/IF 142.5 kHz; 2 AF stage(s)

• Tuned circuits
• 7 AM circuit(s)

• Wave bands
• Long Wave and/or Very Low Frequency (VLF).

• Power type and voltage
• Storage and/or dry batteries / 24-28 Volt

• Loudspeaker
• - For headphones or amp.

• Power out
• 0.3 W (unknown quality)

• Material
• Metal case

• from Radiomuseum.org
• Model: Beacon Receiver Model 438 - Detrola; Detroit MI

• Shape
• Rack

• Dimensions (WHD)
• 108 x 108 x 186 mm / 4.3 x 4.3 x 7.3 inch

• Notes

• The Beacon Receiver Model 438 is the version produced by Detrola of the Beacon Range Receiver identified as BC-1206. Another version is the Model 524 Beacon Receiver produced by Setchell Carlson.

  The 524 and 438 are physically interchangeable and have almost identical performances (200-400 kHz coverage, 3-5 μV sensitivity for 10 mW output, current drain of 0.75 A at 24 V, power output of 300 mW and provision for 300 ohm or 4000 ohm headsets) but, despite the common architecture, rely on different layouts and tubes (14A7, 14A7, 14J7, 14R7, 28D7 for the 524 and 6K7, 6SA7, 6SK7, 6SQ7, 28D7 for the 438).

  The 524 and the 438 have also different IF frequencies (135 kHz the first, 142.5 kHz the second).

  The receiver was not intended for direction finding but only for establishing whether a specific beacon station could be received and was endowed with a short antenna.

  There also are "early" and "late" versions of Model 438. The postion of the audio output transformer is different, along with the type and number of audio output tubes and some cosmetic differences.   The early version has the transformer in the upper part of the chassis, whereas the late version has the transformer on the bottom of the chassis between components.  The early version has five tubes and uses a 28D7 for the output, whereas the late version has six tubes with two 25L6 output tubes.  The volume control for the early version resembles a long screw, whereas the late version has a round knob similar to the tuning knob.

   

• Net weight (2.2 lb = 1 kg)
• 1.640 kg / 3 lb 9.8 oz (3.612 lb)

• Mentioned in
• Setchell Carlson Model 524 Instruction Manual

• Author
• Model page created by Roberto Guidorzi. See "Data change" for further contributors.

• Other Models

• Here you find 330 models, 192 with images and 287 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Detrola; Detroit (MI)