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Rockwell Collins 618T-3 avionics HF SSB transceiver full restoration



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This is a video of a full restoration that I did for the Collins 618-3 HF SSB avionics transceiver. The Collins 618T is a true vintage engineering marvel worthy of preserving. The first ones of these entered the market around 1965, after a 3 year engineering effort by Collins. It was produced all the way into the Eighties, after it was replaced with the fully solid state 628T radio (also shown at the end of this video).
The Collins 618T radio might look like an unappealing black box, but it is one of the most innovative and iconic transceivers Collins has ever produced. It paired versatility to superb reliability and as such it was used in almost every larger airplane of the time (the B747 had two of them installed), including the military. Numerous units have been sold; it was one of Collins most successful products. It also was used in many land-mobile and stationary applications, both military and civilian. Collins started the design for this radio during the early Sixties and the result was way ahead of its time.
The 618T was the first automatic compact HF SSB transceiver that Collins came out with. A radio that can cover the full shortwave range from 2 MHz to 30 MHz in 1 kHz increments, fully auto-tuned. The user only has to set the desired operating frequency from the remotely mounted control box. As such, the radio can generate 28000 user-selectable frequencies, all locked against a high-stability master oscillator with an accuracy of 0.8 PPM.
Keep in mind this radio was designed before the availability of digital dividers or digital synthesizers, it is all done in a fully analog design. A truly superb design effort, especially when you consider the limitations of the available technology at that time. Today's engineers have it much easier. You need to design an SSB radio? Grab some DDS chips from the web-based databook, and some DSP's with the software library for RF processing already done by the chip supplier, and off you go...
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Audio
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