[John KC0G]

Much of the Marconi equipment being discussed in this thread was described in their in-house journal "Point-to-Point Telecommunications", which became "Point-to-Point Communication". Here is a list of references from the period in question, ie ca. 1968 to 1974.

1. P.L. Painter, Hydrus - a new H.F. Receiving Equipment, Point-to-Point Telecommunications, Vol. 12, no. 2, April 1968, pp 82-96

2, R.L.J. Awcock, A. Bell, and J.A. Gould, Naval Communications, Point-to-Point Telecommunications, Vol. 12 no. 4, October 1968, pp 198-212

3. K.A. Barratt, The Design of an M.F. and H.F. S.S.B. Spot-Frequency Receiver for Mercantile Marine Use, Point-to-Point Telecommunications, Vol. 12, no. 4, October 1968, pp 265-264
(Eddystone)

4. D.W. Ford, Solid-state General Purpose Receiver 10kHz to 30MHz, Point-to-Point Telecommunications, Vol. 13 no. 1, January 1969, pp 4-12
(Eddystone EC958 receiver)

5. B.M. Sosin, A Breakthrough in H.F. Receiver Design, Point-to-Point Communication, Vol. 14, no. 1, January 1970, pp 4-14
(H2901 receiver)

6. J.A. Gould, A new 100W Solid-state Transmitter and Receiver, Point-to-Point Communication, Vol. 14, no. 2, April 1970, pp 65-73
(HF1030 "Aries" transmitter, and HF2310 "Argo" receiver)

7. J.V. Beard, A Survey of Communication Receivers, Point-to-Point Communication, Vol. 14, no. 3, August 1970, pp 110-120
(covers H2102 MST, H2002 MST, H2001 Hydrus, H2900 series, EC958 series, H2310 Argo, N2020, N2023)

8. B.M. Sosin, H.F. Receiver Reception Failure Factor, Point-to-Point Communication, Vol. 18, no. 1, January 1974, pp 4-17
(corrected and re-issued as a separate publication, with the same title).

9. C.J. Mellor and R.T. Sutton, Improved General Purpose Communication Receiver, Point-to-Point Communication, Vol. 18, no. 1, January 1974,
(Eddystone EC958/7 receiver)

Pat Hawker, G3VA, often mentioned new professional equipment in his Technical Topics column in the RSGB's magazine, then called "Radio Communication". For example, some relevant items to the present discussions were::
Jan 1968 RA 217 and GEC RC410
Apr 1968 Redifon R499
May 1968 Marconi Hydrus, and references the article by Painter

Jan 1969 RX design, and references the article by Barratt
Feb 1969 Eddystone EC958, and references the article by Ford

Feb 1970 Marconi H2900, and references the article by Sosin

Jan 1971 Sosin and the term "Reciprocal Mixing"

Apr 1974 Sosin's (infamous) article on H.F Receiver Reception Failure Factor
Jun 1974 update on Sosin's article.
Dec 1974 Eddystone EC958/7, and references the article by Mellor and Sutton.

Other useful references are:

Pat Hawker, G3VA, Communications Receivers, Wireless World, June 1970, pp 256-260

Communications Receivers - abridged specifications, Wireless World, June 1970, pp 305-308, 310-311

R.T. Sutton, Eddystone Radio - A Short History of Radio Receiver Developments from 1965-1995, Conference on 100 Years of Radio, 5-7 September 1995, IEE Conference Publication No. 411, pp 134-140

73 John KC0G