• Country
• Great Britain (UK)

• Manufacturer / Brand
• Invicta Radio Ltd.; Cambridge, London

• Year
• 1938

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 108950

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

• Number of Tubes
• 6

• Valves / Tubes
• TH4A VP4B TDD4 PenA4 TV4 IW4/350

• Main principle
• Superheterodyne (common); ZF/IF 465 kHz; 2 AF stage(s)

• Tuned circuits
• 6 AM circuit(s)

• Wave bands
• Broadcast, Long Wave and 2 x Short Wave.

• Power type and voltage
• Alternating Current supply (AC) / 200; 220; 240 Volt

• Loudspeaker
• Electro Magnetic Dynamic LS (moving-coil with field excitation coil) / Ø 8 inch = 20.3 cm

• Power out
• 8 W (unknown quality)

• Material
• Wooden case

• from Radiomuseum.org
• Model: Monomatic 500 - Invicta Radio Ltd.; Cambridge,

• Shape
• Tablemodel, high profile (upright - NOT Cathedral nor decorative).

• Dimensions (WHD)
• 430 x 520 x 285 mm / 16.9 x 20.5 x 11.2 inch

• Notes

• Magic eye. Five preset stations and wavebands selected by Monomatic tuning knob.

  A suffux to the model indicates factory tuned stations (2 x LW and 3 x MW). The "S" suffix was presumably tuned by the Dealer as it's to customer instructions. However the coils are identical for all versions. Tuning of each button is limited as it uses fixed mica capacitors with small parallel trimmer capacitors.

  Suffix pretuned Options:

  • A: Droitwich, Luxembourg,London Regional, Midland Regional, Fecamp.
  • B: Droitwich, Luxembourg, North Regional, Stagshaw, Athlone.
  • C: Droitwich, Luxembourg, West Regional, Midland Regional,Fecamp.
  • D: Droitwich, Luxembourg, Scottish Regional, Athlone, Lyons.
  • E: Droitwich, Luxembourg, Athlone, Scotish Regional, Stagshaw.
  • F: Droitwich, Luxembourg, Athlone, North Regional, Scotish Regional.
  • S: Two Longwave  and three Medium wave stations tuned to customer's instructions.

  Station names are illuminated as the switch is turned.

  Wavebands:

  • SW2: 13.5 .. 52 m
  • SW1:  50 .. 200 m
  • MW: 200 .. 560 m
  • LW: 800 .. 2100 m

  Mentioned on the brochure with 500 (but not illustrated) is the 502 is a Radiogram version and 503 an auto-radiogram version apparently using a similar chassis  with 5 preset stations (similar factory options). But the 502 and 503 also can tune TV sound (A.M. on approximately 5.5 m band or 41.5MHz for Ch1 405 Lines System A) as well as the same coverage / bands as this model. The other differences apart from the single play or autochanger record player is a 10" rather than 8" loudspeaker and a different cabinet 27³/₄" x 33⁵/₈" x 16³/₄", AC mains 40Hz to 60Hz only. No other details.

  Piano finish Walnut cabinet. Five colour edge lit glass scale.

  Power consumption 80W. Standard version is 200 to 250V, 40Hz to 100Hz only. There may be other versions (See notes on 430).

  Three position tone control and tone compensated volume control

• Source of data
• - - Manufacturers Literature

• Literature/Schematics (1)
• Trader Service Sheet (suppl. of Wireless & El. Trader, etc.) (330)

• Author
• Model page created by Norbert Haselbach. See "Data change" for further contributors.

• Other Models

• Here you find 117 models, 68 with images and 82 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Invicta Radio Ltd.; Cambridge, London