SCR-108

The SCR-108 Radio Truck was a Signal Corps Radio vehicle used by the United States Army during and after World War I for short range air-to-ground communications,

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 one 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 six volt circuit is provided for two lamps connected to storage batteries, and a 110 volt circuit with two 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 (500 kHz - 1500 kHz)
• 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 (600 kHz - 1200 kHz), and receiving 200 to 600 meters (500 kHz - 1500 kHz).
• 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 (250 kHz - 600 kHz)
• SCR-121 Amplifier- (BC-44), 2 stage vacuum tube audio amplifier using iron core transformers

Variants

The SCR-124 was evidently 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

See also

• Radio Tractor
• Signal Corps Radio
• Crystal radio

References

• Signal Corps Storage Catalog https://books.google.com/books?id=WgKAfBPtDL8C&dq=scr+54+radio&pg=PA33
• Radio Communication Pamphlet No. 3 (SCR-54) https://books.google.com/books?id=LSxJAQAAIAAJ&dq=scr+54+radio&pg=RA1-PA29
• Radio Communications Pamphlet No. 17 (SCR-79)https://books.google.com/books?id=LSxJAQAAIAAJ&dq=scr+54+radio&pg=RA1-PA29
• Radio Communications Pamphlet No. 22 (SCR-67)

External links

• https://web.archive.org/web/20100413132056/http://www.gordon.army.mil/ocos/museum/equipment.asp scr and bc lists
• Annual report https://books.google.com/books?id=VBE_AAAAYAAJ&dq=scr-108+radio&pg=PA259
• 1922 Congressional hearing https://books.google.com/books?id=IA49AAAAYAAJ&dq=scr-124+truck&pg=PA210