Royal 500 Ch= 7ZT40

Zenith Radio Corp.; Chicago, IL

  • Year
  • 1956/1957
perfect model
  • Category
  • Broadcast Receiver - or past WW2 Tuner
  • Radiomuseum.org ID
  • 69090
    • alternative name: Chicago Radio Lab

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

 Technical Specifications

  • Number of Transistors
  • 7
  • Main principle
  • Superheterodyne (common); ZF/IF 455 kHz; 2 AF stage(s)
  • Tuned circuits
  • 5 AM circuit(s)
  • Wave bands
  • Broadcast only (MW).
  • Power type and voltage
  • Dry Batteries / AA: 4 x 1.5 Volt
  • Loudspeaker
  • Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) / Ø 2.75 inch = 7 cm
  • Power out
  • 0.1 W (0.18 W max.)
  • Material
  • Plastics (no bakelite or catalin)
  • from Radiomuseum.org
  • Model: Royal 500 Ch= 7ZT40 - Zenith Radio Corp.; Chicago,
  • Shape
  • Very small Portable or Pocket-Set (Handheld) < 8 inch.
  • Dimensions (WHD)
  • 3.5 x 5.75 x 1.5 inch / 89 x 146 x 38 mm
  • Notes
  • The Zenith Royal 500 is a battery operated 7 transistor portable BC band radio. The tuning range is 540-1600kHz. The first 4 models are aluminum chassis, hand wired, point-to-point, and have 4 different chassis numbers due to limited quantities of transistors from manufacturing suppliers. The later 4 models are PCB and included vernier tuning. Chassis have chassis numbers along with a Color Code Dot in the battery compartment with labels in the same Color Code ink.

    Year Chassis Number Chassis Type Transistor Source Color Code Dot Cabinet Colors Vernier Tuning
    55/56 7XT40 Circuit #1 Hand Wired Sylvania
    (NPN)
    Black R,Y N
    55/56 7XT40 Circuit #2 Hand Wired Sylvania
    (NPN)
    Maroon R,Y N
    55/56 7XT40Z Hand Wired Raytheon
    (PNP)
    Red R,Y N
    55/56 7XT40Z1 Hand Wired Texas Instr. (NPN & PNP) Green R,Y N
    56/57 7ZT40 PCB Sylvania
    (NPN)
    Magenta R,W,Y Y
    56/57 7ZT40Z1 PCB Texas Instr.
    (NPN & PNP)
    Brown R,W,Y Y
    57/58 7ZT40 "Revised" PCB Sylvania
    (NPN)
    Magenta L,R,V,W,Y Y
    57/58 7ZT40Z PCB Raytheon
    (PNP)
    Orange L,R,V,W,Y Y

    Color Codes:
    L = Tan/Beige (rare); R = Maroon/Burgundy/Garnet Red (semi-transparent); V = Tango Pink (rare); W = White; Y = Black/Ebony.

  • Net weight (2.2 lb = 1 kg)
  • 1 lb 3 oz (1.187 lb) / 0.539 kg
  • Price in first year of sale
  • 75.00 USD
  • External source of data
  • Ernst Erb
  • Literature/Schematics (1)
  • Transistor Radios 1954-68 (Antique Radio Magazine n.61, June-July 2004, page 53 (Ita/Eng). Free at Aldo Andreani's website.)
  • Literature/Schematics (2)
  • - - Manufacturers Literature (Zenith Supplementary Service Manual "Royal 500" All Transistor Portable Radio Chassis 7ZT40 7ZT40Z1)
  Radio a transistor tascabili americane: Zenith Royal 500 “Owl Eyes” (Per cortesia di L.Salvatore/ARM) 3327 KB
  • Documents regarding this model

 Collections | Museums | Literature

Collections

The model Royal 500 is part of the collections of the following members.

 Forum

Forum contributions about this model: Zenith Radio Corp.;: Royal 500 Ch= 7ZT40

Threads: 1 | Posts: 3

Wer kann bitte klären: Ich habe dieses Gerät aber innen mit Chassis-Bezeichnung 7Z T40Z . Ähnlich - identisch mit dem gelisteten oder eine Abweichung. Danke Eckhard Wegner

Eckhard Wegner, 17.Feb.08

Weitere Posts (3) zu diesem Thema.