• Country
• Switzerland

• Manufacturer / Brand
• Hofrela, Hochfrequenzlaboratorium; Zürich, ab 1938 Grenchen

• Year
• 1944/1945

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 12079

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

• Number of Tubes
• 6

• Valves / Tubes
• ECH21 EF22 EF22 EBL21 EM4 AZ21

• Main principle
• Superheterodyne (common); ZF/IF 470 kHz

• Tuned circuits
• 6 AM circuit(s)

• Wave bands
• Broadcast, Long Wave and more than two Short Wave bands.

• Power type and voltage
• Alternating Current supply (AC) / 110-250 Volt

• Loudspeaker
• Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) / Ø 21 cm = 8.3 inch

• Material
• Wooden case

• from Radiomuseum.org
• Model: 645 - Hofrela,

• Dimensions (WHD)
• 610 x 410 x 310 mm / 24 x 16.1 x 12.2 inch

• Notes
• Spulenrevolver; 7 x KW

• Price in first year of sale
• 800.00 SFr

• External source of data
• E. Erb 3-907007-36-0

• Source of data
• Radiokatalog Band 2, Ernst Erb

• Circuit diagram reference
• Thali-Schemasammlung und Tungsram-Röhrenbestückung.

• Mentioned in
• Radios von gestern, 1. Auflage

• Picture reference
• Das Modell ist im «Radiokatalog» (Erb) abgebildet.

• Other Models

• Here you find 5 models, 5 with images and 5 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Hofrela, Hochfrequenzlaboratorium; Zürich, ab 1938 Grenchen