The Heathkit Model SB-220 Linear Amplifier is a completely self-contained, table top. grid. linear amplifier. It is designed to operate at the maximum amateur ... unpacking, parts identification, tools, wiring, soldering. and step-by-step awnbly procedures. PARTS LIST Check each part against the following list. The key numbersThe kit provides all parts necessary to build the 2 Meter Kilowatt amplifier RF deck, and will work with the Freescale MRFE6VP1K25H, the NXP BLF578XR or the newer BLF188XR LDMOS devices. The board included in the kit has all the latest improvements (temperature compensated bias circuit, separate DC drain feeds to reduce transformer heating, and ... A linear amplifier is an electronic circuit whose output is proportional to its input, but capable of delivering more power into a load. The term usually refers to a type of radio-frequency power amplifier, some of which have output power measured in kilowatts, and are used in amateur radio. Other types of linear amplifier are used in audio and laboratory equipment. Discovery Power Amplifiers - The Discovery series of amplifiers are designed and built in the UK by Linear Amp UK Ltd, one of the world's leading amplifier manufacturers, specializing in high power RF tube amplifiers. The amplifiers use large GS31 or GS35 ceramic triode tubes.