SCR-108

The SCR-108 Radio Truck was a mobile Signal Corps Radio used by the U.S. Army during and after World War I, for short range air to ground communications, [[File:Signal Corps Radio Truck 1920.jpg|300px|left

Use

This truck was assigned to squadron headquarters in order to communicate with the SCR-68 airplane radio as well as the others in its class. eventually replaced by the SCR-197 mobile radio station. The van is described as having room for 3 operators and one squadron radio officer. One bench supports the SCR-67, SCR-54, and 1 amplifier with storage batteries held by clamps underneath the bench. on another bench is the SCR-79. a desk for the officer is installed with batteries underneath. a 6 volt circuit is provided for 2 lamps connected to storage batteries, and a 110 volt circuit with 2 lamps is provided if there is an external power source available.

Components

(Note- all sets seem to have been upgraded to an A model)

• SCR-54 Receiver- (BC-14), Crystal detector; inductively coupled; tuned primary and secondary; 150 foot inverted L antenna; wavelength range, 200 to 600 meters.
• SCR-67 Radiotelegraph- (BC-13), transmitting and receiving; for ground stations; has 1 oscillator, 1 modulator, 1 detector, and 2 amplifier vacuum tubes; wavelength range transmitting 250 to 450 meters, and receiving 200 to 600 meters.
• SCR-79 Radiotelegraph- (BC-25), transmitting and receiving; consists of an electrostatically coupled vacuum tube oscillator circuit for transmitting, and a vacuum tube detector and 2 stage amplifier for receiving; requires a low resistance antenna. wavelength is 500 to 1.100 meters
• SCR-121 Amplifier- (BC-44), 2 stage vacuum tube audio amplifier using iron core transformers

Variants

The SCR-124 was evedently housed in a similar truck, and was assigned to division and Corps level headquarters. it carried the following components-

• SCR-99 Radiotelegraph
• SCR-121
• SCR-54
• SCR-82 battery charger (replaced by SCR-110)
• SCR-79.
• SCR-97 Radiotelephone