Sparton 930AC Equasonne

• Country
• United States of America (USA)

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

• Year
• 1928–1930

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 58953

• Picture
• Schematics

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

• Number of Tubes
• 9

• Valves / Tubes
• C-485 C-485 C-485 C-485 C-485 C-485 182B or C-182 182B or C-182 280

• Main principle
• Radio Frequency Amplification only

• Tuned circuits
• 4 AM circuit(s)

• Wave bands
• Broadcast only (MW).

• Power type and voltage
• Alternating Current supply (AC) / 3 taps, 100 to 110, 110 to 120 and 120 to 130 Volt

• Loudspeaker
• Electro Magnetic Dynamic LS (moving-coil with field excitation coil)

• Material
• Wooden case

• from Radiomuseum.org
• Model: Sparton 930AC Equasonne - Sparks-Withington Co., Sparton

• Shape
• Console with any shape - in general

• Notes

• The Sparton 930 (AC) Witherington model has one dial (primary tuning control knob) and offers a push-pull audio amplifier. Tubes according to the "Quantity and Types of Tubes" by Sparks-Withington for season 1928/29 would be the tubes of model 591: 6 x 485 Sparton, 2 x 482B and 80 but this is replacements!
  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. The 482-B would be the replacement for the 182-B or C-182.
  See 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."

• Price in first year of sale
• 169.00 $

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

• Literature/Schematics (1)
• Sparton Radio Service Manual (Sparton Manual 1, Bulletin 11-1, 2, Bulletin 6-3, 4)

• Other Models

• Here you find 807 models, 365 with images and 754 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Sparks-Withington Co., (Sparton); Jackson, Michigan