UHF Same Frequency Research Repeater.
Final technical rept. May 67-Jul 68,
RAYTHEON CO SUDBURY MA SPACE AND INFORMATION SYSTEMS DIV
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The report describes the work performed to design and build a sampled repeater, capable of receiving and transmitting amplitude modulated voice messages within the same UHF channel. The repeater, operating at any of four crystal controlled frequencies in the 225-250 MHz band, was flight tested late in 1967. The flight tests were successful in proving the feasibility of utilizing a sampling voice repeater in an aircraft. The flight tests consisted of actual voice transmission relay by the airborne repeater between two terminals out of line-of-sight. The problem of backscatter of the transmitted signal by the ground back to the relay receiver was solved by offsetting, within the same channel, the transmitting frequency from the received frequency. The amount of this offset, in addition to the sampling frequency, duty factor and pulse weighting were adjustable in order to determine the optimum values of these parameters under flight conditions. The output power was 4 watts carrier, non commutated and 1.8 watts carrier, commutated at a .45 duty cycle. Author
- Radio Communications