• Country
• United States of America (USA)

• Manufacturer / Brand
• Jackson (The) Electrical Instrument CO., Dayton

• Year
• 1958–1961

• Category
• Service- or Lab Equipment

• Radiomuseum.org ID
• 192993

• Number of Transistors

• Semiconductors
• 1N51_Diode

• Wave bands
• - without

• Power type and voltage
• Alternating Current supply (AC)

• Loudspeaker
• - - No sound reproduction output.

• Material
• Leather / canvas / plastic - over other material

• from Radiomuseum.org
• Model: Dynamic Tube Tester 648-R - Jackson The Electrical

• Shape
• Tablemodel, with any shape - general.

• Dimensions (WHD)
• 415 x 170 x 370 mm / 16.3 x 6.7 x 14.6 inch

• Notes
• 648R replaced 648A in October of 1958. Changes are; removal of large 7 pin socket, pilot light and noise test, 1S5 tube is replaced with 1N51 diode. On outside changes are only cosmetical, sockets (9 pcs) are moved to socket bay (for later easy upgrade) and roll chart is moved to separate easy remouvable compartment above the tester.
  All 648 series tube testers share same operation principle (advanced emission test which applys different voltages to different electrodes during test) and same test settings, tubes that measure below 70% and above 130% should be discarded. Similar to other 648 series tube testers circuit is operated with two power transformers (separate for filament and anode), and schematic is stampled on the bottom of the case.
  Absence of grid emission (gas test) is only drawback of this tester. 648R was replaced with 648S in July 1961.

• Net weight (2.2 lb = 1 kg)
• 8 kg / 17 lb 9.9 oz (17.621 lb)

• Price in first year of sale
• 130.00 $

• Source of data
• - - Data from my own collection

• Author
• Model page created by Sinisa Trlin. See "Data change" for further contributors.

• Other Models

• Here you find 64 models, 61 with images and 17 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Jackson (The) Electrical Instrument CO., Dayton