Sparton 79-A Equasonne

• Country
• United States of America (USA)

• Manufacturer / Brand
• Sparks-Withington Co., (Sparton); Jackson, Michigan

• Year
• 1928/1929

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 58912

• Picture
• Schematics

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

• Number of Tubes
• 8

• Valves / Tubes
• C-485 C-485 C-485 C-485 C-485 C-485 50 80

• Main principle
• TRF without regeneration

• Tuned circuits
• 4 AM circuit(s)

• Wave bands
• Broadcast only (MW).

• Power type and voltage
• Alternating Current supply (AC) / 110-130 Volt

• Loudspeaker
• - For headphones or amp.

• Material
• Wooden case

• from Radiomuseum.org
• Model: Sparton 79-A Equasonne - Sparks-Withington Co., Sparton

• Shape
• Console with any shape - in general

• Notes

• The Sparton 69 and 69-A have one dial (primary tuning control knob). These models share the same schematic: 69, 79-A and 89 without naming the tubes and we think that 69-A is existing too because it is named below (in Radio Retailing). The list "Quantity and Types of tubes" from Sparks-Withington shows us for model 69: 6 x 485 Sparton, 50 and 80 but that is already the replacement!
  The models 39, 69, 79-A, 89, 89-A, 99, 109 and 930 are the first "Equasonne" models. The tubes are the original line up, not replacement, according to the page "The quantity and types of tubes used in Sparton receiving sets" and of Rider's page Sparton 5-6, replacement for the C-485, C-484 or 484 would be the 485_Sparton. See also the article here about different radio seasons.

  In "Radio Retailing" May 1933, page 47, "Tricks of the Trade" we can read for models Sparton 69-A, 79-A, 930AC, 931AC, 931DC, 301DC and 301AC: "Fourth section of band-pass selector, just preceding RF sometimes cannot be tuned to resonance with first three sections, producing weak reception and loss in selectivity. Give first, second and third selector trimmers 3 turns clockwise. This makes slightly less tuning capacity necessary for given frequency and fourth section selector can not be adjusted for resonance. Balance set in customary manner with oscillator and output meter and re-adjust kilocycle scale on dial by loosening it on shaft and re-setting."

• External source of data
• Ernst Erb

• Source of data
• Radio Collector`s Guide 1921-1932

• Circuit diagram reference
• Rider's Perpetual, Volume 1 = 1931/1934 (for 1919-1931)

• Mentioned in
• Radio Manufacturers of the 1920's, Vol. 3 (Rider's 1-7)

• Literature/Schematics (1)
• Sparton Radio Service Manual (Sparton Manual 1, Bulletin 7-1, 2, Bulletin 6-3)

• Other Models

• Here you find 773 models, 361 with images and 720 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Sparks-Withington Co., (Sparton); Jackson, Michigan