501A Harp

• Country
• United States of America (USA)

• Manufacturer / Brand
• DeWald Radio Mfg. Corp., Pierce Airo Inc.

• Year
• 1939

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 37458

• • Brand: Pierce Airo

• Picture
• Schematics

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

• Number of Tubes
• 5

• Valves / Tubes
• 12SA7 12SK7 12SQ7 50L6GT 35Z5GT

• Main principle
• Superheterodyne (common); ZF/IF 455 kHz; 2 AF stage(s)

• Tuned circuits
• 6 AM circuit(s)

• Wave bands
• Broadcast only (MW).

• Power type and voltage
• AC/DC-set / 105-125 Volt

• Loudspeaker
• Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) / Ø 4 inch = 10.2 cm

• Material
• Catalin (a brand name for a thermosetting polymer popular in the 1930s and 1940s - a phenol formaldehyde resin - like Bakelite, but a two-stage process with a lot of work afterwards).

• from Radiomuseum.org
• Model: 501A Harp - DeWald Radio Mfg. Corp.,

• Shape
• Design Radio or Novelty / Gadget - fancy or unusual shape.

• Dimensions (WHD)
• 9.75 x 6.5 x 5.6 inch / 248 x 165 x 142 mm

• Notes

• DeWald on the case, but not on the dial.
  Built-in loop as first RF circuit. Date see tube list, can not be earlier than 1939.

• Net weight (2.2 lb = 1 kg)
• 2.5 kg / 5 lb 8.1 oz (5.507 lb)

• External source of data
• Ernst Erb

• Source of data
• The Radio Collector's Directory and Price Guide 1921 - 1965

• Circuit diagram reference
• Rider's Perpetual, Volume 12 = ca. 1941 and before

• Other Models

• Here you find 442 models, 195 with images and 344 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from DeWald Radio Mfg. Corp., Pierce Airo Inc.