• Country
• United States of America (USA)

• Manufacturer / Brand
• General Radio Company; Cambridge (MA)

• Year
• 1946 ?

• Category
• Service- or Lab Equipment

• Radiomuseum.org ID
• 130358

• • alternative name: GenRad

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

• Wave bands
• - without

• Power type and voltage
• No Power needed

• Loudspeaker
• - - No sound reproduction output.

• Material
• Wooden case

• from Radiomuseum.org
• Model: Variable Inductor 107M - General Radio Company;

• Shape
• Tablemodel, with any shape - general.

• Dimensions (WHD)
• 6.5 x 8.75 x 6.5 inch / 165 x 222 x 165 mm

• Notes

• The General Radio 107M is a variable inductor. The model consists of two coils, a rotor and a stator, which are mounted concentrically.  As the position of the rotor is changed, the coupling between the two coils changes, thus causing the inductance to vary.  The total inductance range is over 25:1. The maximum power is 15W.

  Separate terminals are brought out for both the rotor and the stator so that they may be connected in series or in parallel as a self-inductor, or used separately as a mutual inductor.

  The 107 was available in 5 different versions, each covering a different range of inductances:

  Model	Mutual Inductance	DC Resistance	Self-Inductance (Series)	Self-Inductance (Parallel)
  107-J	0 - 10.8 uh	0.05 ohms	8 - 50 uh	2 - 12.5 uh
  107-K	0 - 110 uh	0.38 ohms	80 - 500 uh	20 - 125 uh
  107-L	0 - 1.1 mh	4.6 ohms	0.8 - 5 mh	0.2 - 1.25 mh
  107-M	0 - 11 mh	32 ohms	8 - 50 mh	2 - 12.5 mh
  107-N	0 - 110 mh	410 ohms	80 - 500 mh	20 - 125 mh

   

• Net weight (2.2 lb = 1 kg)
• 5 lb (5 lb 0 oz) / 2.270 kg

• Author
• Model page created by a member from A. See "Data change" for further contributors.

• Other Models

• Here you find 241 models, 212 with images and 131 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from General Radio Company; Cambridge (MA)