A number of dates in the article below are contested by both Geoff G4AFJ and Dave G8MZY so alhough we are reproducing the original article, all dates are suspected to be between 4 and 6 years too early
Written by Jack G3PVG
Around 1970 the Leicester Repeater Group was formed at an inaugural meeting in one of the lecture rooms of the Area Health Authority, courtesy of Les G4CWD. Several projects were discussed, but the one which came to fruition first was a 70cm repeater. The machine was fabricated from a number of PMR components by Barry Doel G3SXK, who at that time was the Chief Engineer for a PMR Company in the Saffron Lane area of the city. The company called Contact Radio Telephones has long been defunct. A number of his engineers and colleagues were involved at the time, and notably Eric Goodwin, G3MNQ, who built the Logic entirely from discrete CMOS "A" Series logic Chips.
The project took some two years to complete, and during the final phases was "operational", into a dummy load of course, in the bedroom of Barry G3SXK just off the Hinckley Road. It was really amazing just how leaky that dummy load was, and how many people were able to access the box from just about anywhere in the city! Many sites in and around Leicester were considered, but the current one was by far the best, and much effort was placed into trying to obtain it for use as a repeater site. The site was an old Royal Observer Corp underground bunker site, and was considered to be secure and ideally located from an RF point of view.
A planning application was made on behalf of the Repeater Group, for the Markfield Site as it is today, for use as an amateur repeater site. The application was refused and an appeal was made. In the event, the appeal was unsuccessful, and it became clear that the Repeater Group, had in the eyes of the authority, become associated with Contact Radio Telephones. Since at that time, the authority would not allow the site to be used for PMR purposes the application was turned down because of the commercial implications!
Since time was of the essence, it was clear that another application from the Repeater Group would in the near future at least, also be unsuccessful, it was decided that an alternative approach might bear fruit. Many of the active locals in the Repeater group were also active in Raynet. The Controller was Chris Heyward G4CUK, or the "Cock Up Kid" as he was referred to by his friends. The Deputy Controller was Jack Bennett, and we got together with several other locals who were active members of both groups, to submit a planning application on behalf of the Raynet Group.
The application was submitted, and it too was refused on the grounds of impairment to local visual amenities. This of course was a travesty, as the site and its environs were an absolute tip. So, an antenna, a four element collinear was erected temporarily on a 30 foot steel pole, and photographs taken to show just how insignificant it looked from many different angles. Photographs were also taken, some thirty of them in all, showing all the scrap yards, derelict buildings and rubbish piled high in the gutters of all the surrounding areas and premises. The photographs were of excellent quality and taken by Derek Wills G3XKX, who at the time was employed as a professional photographer. The weight and assistance of the County Emergency Planning Officer was also brought to bear, and he attested to the fact that the Repeater would be an essential item in the operation of the County Emergency Plan. Hence the Emergency Mode which was incorporated into the repeater logic. The Chairman of the Markfield Parish Council, who was known to yours truly personally, later remarked that we killed em dead! Why on earth was the application not done this way in the first place! Thus the planning permission was granted, and the site was rented to Raynet by Markfield Parish Council. Raynet then of course made arrangements for the equipment to be installed on site.
As October 15th came and the licence was granted, it was realised that very little was actually ready, and the equipment would have to be got ready for installation quickly. The repeater itself was still with Barry G3SXK in Cheshunt, and he would not let it go until everything was in place and ready to go. A redundant 60 ft sectional pole was located at Lloyd's TV Service depot in Enderby, and was offered to the Repeater Group subject to its removal by a suitably qualified and insured contractor. The services of Stan G3SQV and his assistant, a SWL, now G4ZQT, were obtained and we gathered one very windy Sunday morning for the de-commissioning of the 60 foot mast mounted on the apex of an industrial building roof. The usual crowd of assisters were present, and to our amazement we saw Stan erect his ladders up the pole, climbing each one to erect the next. When the top was reached, he calmly unbolted the antenna mounted on the top and sent it crashing down to the yard below. He then unbolted each section of the mast and ladders progressing downwards until all of the mast was down. All this in a 40 mph wind at heights of up to 90 ft, amazing! Having got a mast, the process was reversed and the mast re-erected at Markfield. The names of all the helpers were too numerous to list, but a good job was done by all. A 30 Amp 12 Volt DC mains power unit was obtained along with some 12 Volt lead acid batteries for standby use, and these were installed on site.
Christmas 1972 came and went, and still no repeater due to pressure of work for Barry G3SXK. So, at this point it was decided that yours truly would go to Cheshunt and get the machine for installation and firing up on New Years Eve 1972. Upon arrival at Barry's qth, I discovered that the repeater had been in a shed for over a year, and had started to show signs of deterioration. The box was fired up, and of course it didn't work, not even into a dummy load. After much messing about, the time ticking away, we discovered a fault in the through audio. Since no spares were available, we did what can only be described as desperate things. We took an old Europa board and cut out the audio section with a hacksaw. This section of board was placed in a plastic bag and mounted as an outboard unit secured with electrical tape. The board ran with jumper wires as umbilical chords for nearly two years!!
The repeater was installed down the hole by G3PVG and G4CUK who ably assisted in tuning up the cavities. These had been modified and adjusted by Geoff G3TQF. At this time there were several helpers who did a lot of coming and going, fetching bits and pieces and generally doing a lot of good work. I can't remember everybody as there were so many, but a few have stuck in my mind. Brian G4FZL, Dave G8MZY, Mike G8CAC, and Dave G4FSS.
The box was commissioned of sorts and came on air at 0001 hours 1 January 1973. It ran for a while and we were all so tired that we left it to settle down and went home to bed. During New Years Day, I was called out to fix the box which had gone off air! Upon arrival at site it became obvious that the logic had blown up and we had a major problem. Since the breakup of Contact Radio Telephones , there has been several political problems which had the result of no Logic Diagram being available to the group. This meant that the logic had to be fault found with no diagrams. The logic was built on a full size Euroboard with something like 180 chips on board, all of which were "A" series CMOS Logic. Basically what this means is that the chips had little or no noise immunity, and were very susceptible to noise on the power lines. It turned out that this caused a major hic-up in the fault finding routine. The faulty chip could not be sourced locally and was of a type little used. We found a couple in Derby courtesy of Paul G3PXQ using Dave G4FSS as courier! The method of fault finding at this stage was very crude, since we did not have a scope down the hole. The only way was to find the clock oscillator on the board, and slap a very big capacitor across it to slow the clock down far enough, so we could watch the pulses on an Avo 8! The next problem was memorising the results since we had no diagrams.
The helpers were furiously scribbling down the measurement results as we went along! Once again the box was up and running, and it became apparent that the coverage was tremendous. Later on the same day I was again called out as the box had failed again. I was of course supported by the now usual team of helpers. Many hours of work were put in by a few people, so much so that after an all night session and all through the next day, we discovered that the power supply was blowing up the logic. Another all night down the bunker was called for, and I asked Mike G8CAC to pick up some tools and supplies from my house. He turned up with the supplies, the tools and components, and a Jiffy bag from the XYL. When I opened the bag it contained my pyjamas!!
Many sessions similar to these occurred until we became more experienced in the ways of the box, and over the years many people put a lot of time and effort into keeping the various Marks of LE alive and running. Thank you all, to those who took part, however small.
Various Marks of LE have been built and installed, some lasting longer than others. A list of them is given below, but please forgive me if I have left someone out, it certainly isn't intentional.
Mkl -Built by Barry Doel G3SXK & Eric Goodwin G3MNQ
MK2 -Built by John Elliott G8CGW & Bob Bennett G8BFF
MK3 -Built by Paul Toon G8JFD
MK4 -Built by Chris G8LMW
MK5 -Icom 726 with Logic by Don G3IPL
MK6 -Revamp by Adam G0ORY & Don G3IPL
MK7 -New Machine - Content unknown - Adam G0ORY
The machine continues to prosper and is going on to bigger and better things, as does CF, but that's another story!!
Many Happy Returns, Happy Birthday, and many of them!
73, de Jack G3PVG