• Country
• United States of America (USA)

• Manufacturer / Brand
• Motorola Inc. (ex Galvin Mfg.Co. Chicago); Schaumburg (IL)

• Year
• 1958

• Category
• Audio Amplifier or -mixer

• Radiomuseum.org ID
• 154285

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

• Number of Tubes
• 3

• Valves / Tubes
• 12AX7 EL84 6X4

• Main principle
• Audio-Amplification

• Wave bands
• - without

• Power type and voltage
• Alternating Current supply (AC) / 110 - 120 Volt

• Loudspeaker
• 2 Loudspeakers

• Power out
• 4 W (unknown quality)

• Material
• Wooden case

• from Radiomuseum.org
• Model: HK31M Ch= HS-712A - Motorola Inc. ex Galvin Mfg.Co

• Shape
• Console, Lowboy (legs < 50 %).

• Notes
• The Motorola Model HK31M is an AC Operated 3 Tube Audio Amplifier and speaker system to be used as the right channel when converting Motorola models 3H24-3, 3H24-4, 3H25-2 and 3H25-3 to stereophonic operation. Uses chassis HS-712A. Cabinet is Mahogany. This model has Qty(1) 8" PM speaker and Qty(1) 4" PM speaker.

• Literature/Schematics (1)
• Photofact Folder, Howard W. SAMS (Date 11-59, Set 463, Folder 7)

• Literature/Schematics (2)
• - - Manufacturers Literature

• Author
• Model page created by Egon Penker. See "Data change" for further contributors.

• Other Models

• Here you find 4615 models, 2967 with images and 4114 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Motorola Inc. (ex Galvin Mfg.Co. Chicago); Schaumburg (IL)