• Country
• United States of America (USA)

• Manufacturer / Brand
• Zenith Radio Corp.; Chicago, IL

• Year
• 1959/1960

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 148247

• • alternative name: Chicago Radio Lab

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

• Number of Transistors
• 7

• Semiconductors
• 2N411 2N409 2N409 2N409 2N407 2N407 2N407 1N87G

• 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 / 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 275-J Ch= 7CT40Z2 [late] - Zenith Radio Corp.; Chicago,

• Shape
• Very small Portable or Pocket-Set (Handheld) < 8 inch.

• Dimensions (WHD)
• 5.75 x 3.75 x 1.75 inch / 146 x 95 x 44 mm

• Notes

• The Zenith Royal 275-J is a battery operated 7 transistor portable BC band receiver.  The BC band frequency tuning range is 540-1600kHz.  Has push-pull output stage and earphone jack that disconnects the speaker for private listening.

  The Zenith Royal model 275 is available in an early version with the inscription "The Statesman" on the upper front (chassis = 7CT40Z1) and a later version without this (chassis = 7CT40Z2). It looks similar to the Royal 250 but has two-tone cabinets and a gear reduced vernier tuning. As a cheaper radio, it has a plastic case rather the nylon cabinet like the 500 with practically the same chassis.
  
  Please check the color code before uploading pictures.
  The letter suffix is not shown on the model but there are the following codes for colors: 275B (dark blue with a light blue back), 275F (dark green with a light green), 275J (brown and a tan back) and 257Y (black with a beige back). As model name we list with a hyphen as 275-B, 275-F, 275-J and 275-Y so that you get the chance to find by 275 alone or with color suffix.
  
  Both, the early and the late version are featured in Photofact set 486, folder 28 on May 1960.

• Price in first year of sale
• 50.00 $

• Literature/Schematics (1)
• Photofact Folder, Howard W. SAMS (Date 5-60, Set 486, Folder 28)

• Literature/Schematics (2)
• - - Manufacturers Literature (Zenith Service Manual Model "Royal 275" Transistor Portable Radio dated 5-26-59)

• Literature/Schematics (3)
• Beitman Radio Diagrams, Vol. 20, 1960 (Pages 179, 180)

• Author
• Model page created by Ernst Erb. See "Data change" for further contributors.

• Other Models

• Here you find 4517 models, 4109 with images and 3652 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Zenith Radio Corp.; Chicago, IL