A one kilowatt high level modulated UHFamplifier with low distortion

The Communications Laboratory of RADC has completed the development of a vital communications link in the short range ground-to-air communieations. This link is the 1 KW Amplifier - Modulator Group which operates in the military UHF 100-watt transmitters for line of sight (los), ground-to-air communications. The design, development and fabrication of the 1 KW UHF Amplifier - Modulator is discussed. The equipment described provides an RF output of at least one kilowatt over the range 225 - 400 Mcps, when driven by an 80-watt exciter. The equipment also provides high level amplitude modulation (AM) of this RF. 90% or more AM is obtained over the audio range 200 - 22,OOO cps, and 80% or more AM is obtained over the range 22,000 - 25,OOO cps. With 80% modulation of an 1100-watt carrier, the total RMS harmonic distortion over the audio range 200 - 20,OOOcps is less than 3%. It is noted that the design solutions for this project have been jointly solved by engineers of General Electric Canpany, McIntosh Electronics and Rome Air Development Center.