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Old 22nd Mar 2017, 5:47 am   #10
John KC0G
Hexode
 
Join Date: Mar 2009
Location: Minneapolis, Minnesota, USA.
Posts: 275
Default Re: Origin of terms "Roofing filter" and "Reciprocal mixing"

Thank you all for your comments, which prompted me to look further. I had previously looked through some of the articles from Point-to-Point Communication (a Marconi in-house journal) and Technical Topics for several years. That included the July 1966 piece, where I overlooked term “preliminary crystal filter”. :-(

I went back to the two-part paper by G.J. NcDonald and C.S. Burnham,
"Review of progress in mercantile-marine radiocommunication, Part 1. Systems and facilities", Proc. IEE, Vol. 118, No. 11, November 1969, pp 1807-1811
"Review of progress in mercantile-marine radiocommunication, Part 2. Technique and Design", Proc. IEE, Vol. 118, No. 12, November 1970, pp 1812-1820
There is no mention of the terms "roofing filter" or "reciprocal mixing". McDonald was with Marconi International Marine Co., and Burnham was with Marconi Communications Systems Ltd. This adds further credence to the theory that the Sosin was the first person from Marconi to publish these terms. The H2900 was an expensive receiver, and some evidence that it solved known technical problems would have been useful.

In Gosling's book "Radio receivers". Sosin wote the chapter on "Receiver performance and Specifications", and took a certain amount from his 1971 paper.

Pat Hawker referred to the potential effects of phase noise in his Wireless World article in the June 1970 issue, but as stated above did not use the term "reciprocal mixing". The effects of phase noise were discussed in a paper at the IEE Conference on frequency generation and control, by two people from Rohde & Schwarz. It was mentioned by Pat Hawker in Technical Topics in May 1968.

Somewhere I have a book (from the 1970's ?) on noise testing of communications channels. At the moment it is conspicuous by its absence.

I am left wondering where else to look. The first IERE conference on Radio Receivers and Associated Systems was held in 1972 The first IEE conference on HF Communication system was held in 1979. The IEE Radiocommunicaton convention was held in 1963, which is too early for this discussion, but the proceedings are fascinating. That leaves professional journals and in-house journals. The latter from the UK are hard to find here in the U.S.A.
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