Re: ISB Receivers
Regarding the putative general move to the “one box” receiver concept, there was an interesting reference to that in an article on HF receivers in WW 1980 written by R.F.E. Winn of Racal. In a look-back at the RA1772 development, he said: “Another innovation was to provide a complete receiving terminal in a single case instead of extending facilities with add-on adaptor units, which, in the past, had frequently resulted in a 6ft high rack of equipment.”
I imagine that was a reference to the RA17 era and the external adaptors, including SSB and ISB units, that were developed for use with it. Also of course the classic point-to-point ISB receivers such as the Marconi HR21 & co., typically occupied a full rack.
The accompanying block schematic for the RA1772 showed the optional ISB board. The article also referred to the then new “Anglo-American” HF receiver, which I think was the RA1792, and one of whose rationale was much lower cost….As an aside, I wonder if that receiver’s 455 kHz second IF (as compared with 1.4 MHz for the RA1772) was to meet American preferences.
Cheers,
|