Eddystone User Group

Eddystone S640 and S688 speaker go to a good home

March 20, 2023 By: chris Category: News

Those of you who are members of the Eddystone User Groups.io forum will have seen the generous offer on17/3/23 from Andy in  Northumberland of a S640 receiver and S688 speaker Free of Charge to someone who would give it the TLC it deserves. Following his mother’s passing Andy had found the receiver, which belonged to his father, whilst clearing her loft space and he remembers having it in his bedroom as a youngster more than 40 years ago. The set and speaker were quickly claimed by Mike who lived in the same area  and picked up by him the same day.








Mike contacted me to confirm he had picked up the sets and sent in few photographs of himself with his  S940, which he bought new in 1968, waiting for BBC World Service to come on air whilst working in Boston, Massachusetts in 1971. The second picture shows Mike, repairing the RF stage on that same S940 in Northumberland 40 years later. The third picture shows Mike’s impressive collection of Eddystone sets.























My collection moving from left to right an 850/4, my 940 under repair, an “as new” 830/7, an EA12, 770 MkIIR and 770U MkII and an 840C.

Intrigued by such a layout, I asked Mike if he would give us some history about his love of Eddystone’s. He graciously obliged.

Mike’s Story

“I purchased my 940 from Aitkin Bros in Newcastle in late 1968. I had seen a 840C in their window along with a couple of the smaller transistorised models. Aitkins was where we went in Newcastle to buy valves and other radio and TV components and even to get valves tested for a fee. So after some thought I went in and put a £5 deposit on a 840C. But I picked up some brochures at the same time which included one on the 940. So I went back and changed my order to the 940. When it came in I carried it home on the bus with some difficulty. Later I ordered a plinth speaker directly from Eddystone. Around that time I saw an advert in Wireless World which covered the 830,770R and U so I always wondered about them.


Then I was transferred by my employer to the United States near Boston where I lived for many years and took my 940 with me, originally working in Image Analysis Scientific instruments and later in NMR (Nuclear Magnetic Resonance) and MRI which are both radio frequency technologies. Whilst in the US the BBC sent me a monthly program and that is what I have in my hand in the photograph.


I was repairing the RF stage on my 940 after Gerry O’Hara had asked me to make some voltage measurements for him. I had not been using my 940 for other than local radio stations at the time and had not realised that there was a fault but in checking for Gerry I found the usual out of spec carbon resistors so set about replacing them using Graham Wormalds tips for this awkward job. I had gotten to know Gerry when I appealed for some help with the repair of my 770U MkII and Gerry replied. Later by chance both of us together would be replacing and tuning new turret coils at the same time. In my case the Band 3 and 6 coil substrates had deteriorated and crumbled through damp. I did more work on my 770U MkII than any other radio tracking down an intermittent IF gain problem which turned out to be in the coils of the first 50 MHz IF transformer. This differs from the second 50 MHz IF transformer in that it is a a wider band tuning but only the narrow band second stage transformer was available and that worked just fine. I used a modern Marconi digital signal generator to align the set as I did not have much luck using the higher harmonics of my old AVO sig gen.


I also owned at one time an EP17R VHFand an EP20 HF Panadapter and used the EP17R to align my 770U and this work is featured in Gerry’s Detectors and Discriminators article. Also owned a very early 888 but sold that when I got the EA12. My other hobbies are E-Type Jaguars of which I have two so sticking with the “E”

Some additional photographs”   
























Thanks for the story Mike. Good luck with the S640, but you might need a bigger bench

Chris G0EYO

EUG Admin