Welcome to the Vintage Radio Gear site and the Collins 51J resource page. This site is designed to help you quickly and easily find the latest Collins 51J manuals, Collins 51J books, Collins 51J parts and accessories and Collins 51J radios for sale. The Collins 51J information on this site is updated hourly, so if you are interested in the Collins 51J, bookmark this site so you can visit often.
Art Collins founded Collins Radio Company in 1933 in Cedar Rapids, Iowa for the purpose of designing and producing both shortwave and AM broadcast radio equipment and equipment.
The company introduced their first amateur radio receiver, the 75A-1 around 1947. This unit achieved excellent stability due to high build quality and the use of a permeability tuned oscillator (PTO) in its second conversion stage. It was one of the few dual-conversion superheterodyne receivers manufactured at that time and was designed to receive only the amateur bands.
The 75A amateur line was continued throughout the early 50s, ending with the 75A-4, released in 1955. The Collins mechanical filter was introduced in the 75A-3, and the 75A-4 was one of the first receivers marketed specifically as a single sideband receiver.
In 1958 the 75A series was replaced with the much smaller 75S series, part of the S/Line. These top-end receivers featured mechanical filters, excellent stability and very accurate frequency readout.
With the introduction of the S/Line in 1958, Collins moved to an integrated equipment system, making them the first manufacturer to take this approach. Collins was also introduced a compact HF transceiver, the KWM-1, the year before. These two innovations put Collins ahead of its competition and set the stage for other amateur radio equipment makers and the next generation of HF radios.
In 1978, the S/Line came to an end after a two decade run. The KWM-380 transceiver was introduced the next year – innovative in its use of transistors and digital technology, and its styling. It was Collins’ final entry in the amateur radio market until it was discontinued in the mid-1980s.
The Collins Radio Company was purchased by Rockwell International in 1973. In 2001 the avionics division of Rockwell International was spun off to form the current Rockwell Collins, Inc., retaining its name. Rockwell Collins serves the defense and commercial avionics industries and no longer markets receivers to the public. The company today employs over 19,000 people.
More information on Collins Radio:
Wikipedia reference on Collins Radio
Collins Collectors Association
Virtual Collins Radio Museum