• Country
• United States of America (USA)

• Manufacturer / Brand
• Radio Shack (Tandy, Realistic, Micronta); USA

• Year
• 1972 ?

• Category
• Kit (Parts plus instruction) or building instructions only

• Radiomuseum.org ID
• 336076

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

• Main principle
• Special principle (see notes)

• Wave bands
• - without

• Power type and voltage
• Dry Batteries / 9 Volt

• Loudspeaker
• - - No sound reproduction output.

• Material
• Various materials

• from Radiomuseum.org
• Model: Science Fair Indoor-OutdoorThermometer P-box 28-135 - Radio Shack Tandy, Realistic,

• Shape
• Portable set > 8 inch (also usable without mains)

• Dimensions (WHD)
• 4.75 x 3 x 3.75 inch / 121 x 76 x 95 mm

• Notes

• The Science Fair 28-135 P-box kit is a useful thermometer that can be used indoors or outdoors.  Senses termperature from -20 F to 120 degrees F, or calibrate your own scale.  Two thermistors are connected through a switch to a common resistance bridge network and a meter movement.  Uses three trimpots for calibration and a 200 microamp meter.

  The 28-135 is one of a number of small kits developed by Radio Shack that use a plastic chassis called a P-box that can withstand soldering temperatures.

   

• Price in first year of sale
• 8.95 US$

• Mentioned in
• Radio Shack catalog 1972 Version 2, pg 126

• Literature/Schematics (1)
• Kit booklet has schematic and principle of operation.

• Author
• Model page created by Rich Post. See "Data change" for further contributors.

• Other Models

• Here you find 1299 models, 1181 with images and 117 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Radio Shack (Tandy, Realistic, Micronta); USA