At the end of September 1980 I was still uncertain what to do. The 3-year term of my initial QMC contract to work on the UKIRT receivers was to end quite soon. And as yet I had no fresh job lined up. I expected that I might get job offers resulting from my recent visit to the USA, but was starting to feel that I’d prefer to stay in the UK if I could. Derek Martin wanted to find me a new contract, but nothing was settled. The work I was doing for Armstrong Audio still continued to occupy most of my weekends. So I’d probably find employment – but doing what, where?
|The photo on the left shows me standing in front of the mm-wave telescope on the roof of the QMC Physics dept building. The photo on the right shows the Physics building with the dome at the top.|
Above left, the actual telescope behind me looks like a large black object because it is covered over with a large sheet of ‘bin liner’ plastic. This covering is to stop any near IR (heat radiation) or visible light from reaching the telescope’s primary mirror. Without this serving as blocking filter the focussed light from the Sun could have caused damage or started a fire! Bin liner material was ideal because it was cheap, blocked the unwanted heat, yet passes mm-wave radiation with almost no loss.
My first day back to work at QMC after my return from Kansas and New England was Monday 29th September. When I went in I was told that a visit had been arranged for Derek, Nigel Cronin, and myself to go and meet people at Plessey in Towcester the next day about a possible project! It was also on the cards at that point that I’d go to La Palma in November to help with collecting more atmospheric water-vapour measurements to assess how good the site might be as the location for future telescopes. In addition, John Beckman had put in an application to use the new receivers on UKIRT during the first quarter of 1981. He wanted me to go with him to help run the system. Any uncertainty about my future employment certainly wasn’t based on a lack of immediate work, or people asking for my involvement! Perhaps understandably, I wrote in my notebook at the time: “Rats!What about my thesis?!” I was aiming to get this finished by the end of the year and wondering if I could get everything done.
During the next few weeks I continued to exchange letters with Jennifer Weaver, Mary Jane, and Gerry Sollner. But despite all this I’d still was uncertain what choice I might make, if and when I got any job offers from the USA...
In terms of my personal life the 13th and 15th of October showed me just how people can differ. On the 13th I spent the evening with the Beckmans for dinner. Someone I’ll just call Margaret was there too. She had been an undergrad at the same time as myself and I’d met her then – also via a dinner at the Beckmans home. She was very bright in terms of being intelligent, etc. But gave me the same impression as I’d formed of her as an undergrad/postgrad. Her attitude to life seemed very negative and pessimistic, taking a gloomy view of every possibility. I recall that on an earlier occasion I’d made a date with her but she’d failed to turn up. We’d arranged to meet on one of the underground platforms at Liverpool St station. I think the plan was to go to a concert at the South Bank. But she didn’t appear. The reason she gave later was that she’d got onto a circle line train going in the wrong direction and decided it was too late when she’d realised her mistake. This may well have been true. But at the time I felt it was more likely that she didn’t really want to go out with me despite having agreed. Understandable as I wasn’t exactly attractive at the time.
In contrast, on the 15th I went out with Karen Worgan. We went to see a very unusual show titled “Song of the Lion” – partly one-man-show and partly puppet theatre! It was based on the life and works of C. S. Lewis and was excellent. Karen’s reaction was very interesting. She said afterwards that she’d come close to Christianity but regarded herself as a ‘backslider’ being her comfortable permanent state. Her boyfriend, Tom, was a quaker and through him she’d been helping with a group of mentally handicapped children. Karen was bright in every sense. Open, cheerful, helpful, and kind as well as clever. A real joy to be with.
On Friday 17th October Richard Huganin phoned and offered me a job building mm-wave receivers for MIT. Over the next few days as I considered this I continued finishing off my thesis. Apart from general matters like writing up my PhD and continuing to work on the Armstrong amplifiers over most weekends, the main part of my effort was devoted during that October to a particular topic.
One of the key components in mm-wave ‘quasi-optical’ systems like the diplexers were lenses. Ordinary glass is opaque at mm-wave frequencies, so these lenses had to be made of other materials that were sufficiently transparent. For many years a common choice had been ‘TPX’ (at trade-name for methylpentane polymers made by Mitsui). For example, the system used for the Concorde 001 Solar Eclipse experiment in 1973 used TPX lenses. TPX has the advantage of being reasonably transparent at optical wavelengths as well as in the mm-wave region. A bonus was that its refractive index in these two spectral regions was also fairly similar. Hence it was possible to align and check these lenses ‘by eye’ or using visible light sources. In practice, quite a useful property. However TPX wasn’t very transparent and tended to absorb a fair bit of the mm-wave power, hence it tended to limit performance.
There were actually two telescopes on the roof of the QMC Physics building, as shown in the above photo. The lower dome contained a small conventional optical telescope. This and the room under the larger mm-wave telescope were mainly used for teaching purposes.
Preliminary tests on other polymers had indicated that polyethylene and PTFE (Poly Tetra Fluro Ethylene) tended to absorb much less than TPX. But the results also showed variations in performance from one sample to another. Looking at the pre-existing scientific literature it was also clear that the results obtained there were variable. I’d managed to get satisfactory lenses for the UKIRT systems but decided this needed investigating more systematically to try and make future design work easier.
To do this I got in contact with Jim Birch at the NPL and Dave Tod in the QMC Materials Science Department. They were both people I’d known for many years. Jim Birch from the Concorde project – where he was working to see if the use of the high-flying Concorde might affect the upper atmosphere. I’d known Dave Tod from my first day as an undergrad at QMC. Having collected our first-year undergrad paperwork we were all standing in a group in the foyer of the Main Building. I think I gravitated to him because he was tall enough to stand out, and had a local accent similar to mine! From then on we met and studied together along with a small group of other Physics undergrads, and we both stayed on as research students. The only split being that he migrated to Materials Science whilst I joined the QMC Physics Astrophysics Group. Dave was the ideal person to help with obtaining and processing polymer materials. Jim Birch was already well set up to make far-infrared measurements on the properties of materials. I was the person who wanted to nail down the properties of the materials in terms what would be of use for someone designing and building mm-wave optical systems.
To cut a long story short, we then collected a number of samples of many different materials and systematically did measurements on them. In the process it became clear that the best materials did seem to be Polyethylene and PTFE because they could provide the lowest levels of unwanted absorption of the mm-wave power. i.e. they were the most transparent materials we could find. A given sample also tended to have almost exactly the same refractive index across the entire spectral range from below 100 GHz up to over 1 THz. Useful for lenses that sometimes were to be used in wideband instruments.
In practice the Polyethylene came in a range of ‘molecular weights’. This indicate the average size or weight of the polymer chains that formed the molecules in the material. The materials made from long ‘heavy’ molecules tended to be referred to a ‘high density’ or HDPE (High Density Poly Ethylene) whilst materials made using shorter molecules were LDPE (Low Density Poly Ethylene). There was a small but systematic difference between their refractive indexes. But the levels of loss varied quite a lot from one sample to another even for what was, nominally, the same material.
Usually, material of either type was sold in the form of extruded rods or pellets. Tests indicated that buying the rods was a bit like buying wine for a wine-tasting. Lenses made from two different rods of HDPE, say, from the same maker might have distinctly different levels of mm-wave transparency. There were also signs that the material close to the surface of the rod was poorer than the material a cm or more below. The reason these variations was fairly simple. None of them were being made with mm-wave scientists in mind. No-one making them cared one way or another about their optical properties at hundreds of GHz. The rods were extruded to be sold for purposes like making plastic buckets, beer-crates, etc! The extrusion processes started from pellets of HDPE which were then forced though a die to squeeze out into a rod. Like toothpaste from a tube. However the pressures and temperatures involved tended to affect the material. Particularly at the surface of the resulting rod. And various additives were incorporated to make the manufacturing easier. Sadly the resulting rod could then contain chemicals and structures which absorbed mm-wave signals. With Dave Tod I did experiment with trying to make our own blocks of HDPE and LDPE from pellets. But this wasn’t a success. In effect, it was like trying to learn how to cook without any prior experience or advice.
The above tells the story from the point of view of HDPE. The situation for PTFE was similar although that tended to be made and sold in blocks rather than rods. The end result is that we established what ‘good’ and ‘typical’ samples of various materials would offer in terms of refractive index and loss. But also found that in practice it was a good idea to buy and keep a number of rods and blocks of materials, check their properties, and then use the ‘best’ ones as if they were fine old single malt whiskeys to be savoured when there was a need! Using any ‘cooking sherry’ material when the levels of performance required were low enough for the higher loss not to matter.
The graph above shows the refractive index results for all the materials we included in the survey. It is taken from Birch, Dromey, and Lesurf (Infrared Phys. V21 pp 225-228 1981).
The measured results for the materials which seemed the best candidates for use in mm-wave lenses were included in my PhD thesis and published in a journal paper (as per the above illustration). The overall conclusion confirmed that good-quality HDPE and PTFE were the preferred choices because they provided the lowest signal loss. In the published paper the units used for the axies are somewhat arcane. At the time infra-red spectroscopists used ‘wavenumber’ as a measure of frequency. This was defined as being how many wavelengths would fit into one centimetre. e.g. ‘10 per cm’ corresponded to a wavelength of 1mm. The unit was convenient for those carrying out practical measurements because they were done using two-beam interferometers. As one of the interferometer mirrors was moved, altering the path length of one beam, the output would cycle up and down so many times for each cm of change in path difference. Hence a convenient unit for practical spectroscopists... but a head-scratching puzzle for radio astronomers accustomed to GHz!
Lenses were actually made by turning them on a lathe. This required a lot of skill on the part of the machinist because the materials were a lot ‘softer’ than metals. So they tended to deform under pressure, and then only partly spring back when the cutting edge had passed. They also would melt or degrade or small chunks might be ripped out unless cut in exactly the right way. As a result it was, in reality, one thing for me to find a ‘good’ sample of material in optical terms and then hand a chunk to a mechanical technician with a drawing of the precise lens shape I wanted. But It was something else entirely for them to have the skill and patience to actually turn up the required shape with exactly the right surfaces without degrading the material in the process! One lesson I learned very early on is that academic ability isn’t enough in itself if you want to be able to make something that works well. You also need someone with the sheer practical skills required to turn theory into reality. Fortunately for me, the QMC Physics workshop technicians had that to a remarkable degree. In particular I’d like to mention ‘Old Fred’ – an affectionate name for Fred Eskell. He gradually developed a wasting illness and became a bit slow and and shaky. Yet despite that and having to get around using sticks, he was able to machine some superbly precise work. To the point where I and others used to ask for him to do particular tasks because although it might take a bit longer, the results were worth the wait!
When people discuss science and the work of academics and scientists, all too often they overlook the vital contributions made by practical engineers and technicians. It’s all very well to come up with a natty new theory. But unless someone can make observational measurements which can test what the theory says, theory remains hot air. Physics has been defined as the ‘science of measurement’. If you can’t measure it, it ain’t physics! And when you want to push the boundaries of what anyone can measure to test new ideas you need someone you can turn to who can built the kit you need. In the end, that boils down to having people with the necessary practical skills even if they can’t write equations on a blackboard.
Derek Martin’s ‘Engineering Physics’ group was well founded on the above idea. It specialised in devising / developing novel instrumentation and performing challenging measurements. An approach which chimed nicely with my experience developing electronics for industry. In addition, QMC was one of the first UK Universities to set up a ‘commercial’ arm. This was under the general title of ‘QMC Instruments’ and also used other names like ‘QMCIRL’. The idea was to sell items or design consultancy work as a spin-off from the research work being done at QMC. The range of fields this covered was quite diverse. For example, although Infra Red and MM-Wave items were a part, ultrasonic bat detectors were also something of a best seller at the time! As a result of this, I gradually started to do more and more bits of work for QMC Instruments. I’ll say more about that, later on...
On the Monday 20th David Adamson joined Derek Martin’s group as a technician. By this time Chris Adams was starting to make more comments admitting that she’d be sad if I went to the USA. But at the same time she still was unwilling to make our relationship more than a good friendship. I continued going to concerts: with Chris to a “Chieftains” concert on Tuesday 21st where someone sitting beside us annoyingly kept talking all though the music; and on the following night with Karen to the BBC’s 50th Anniversary Concert at the RFH. This included Vaughan Williams’ 5th Symphony which has always been a particular favourite of mine. During that evening Karen said she’d also miss me if I went to the USA.
The above photo was taken from a viewpoint about half the way along the road to Mile End station. It shows what the telescope domes on the roof looked like for someone walking along the road towards the Physics department.
My own behaviour and attitude to life during this period had changed a great deal from when I had been younger. As a result I had drifted almost without thinking about it into a situation where I was frequently going out with various women. Quite a contrast to my period at Armstrong when this was rare to the point of being virtually non-existent! To some extent this probably was a ‘one thing leads to another’ effect – i.e. having been seen to be going out with one or two people from the Physics dept, others who worked there decided I was ‘OK’ and were then themselves happy to have a friendly relationship without feeling that I’d put any unwanted pressure on them. Who knows, maybe they even got together and talked about the men in the department to compare notes! I did sometimes get the feeling that I’d become seen as a sort of ‘brother’ or ‘uncle’ and was regarded as a ‘safe and daftly amusing’ person they felt relaxed to be with. If so, that was fine with me.
I confess that I did find Karen’s behaviour curious in some ways, and I’d wondered for a while if there may have been factors I didn’t know about her situation. She was very happy to go out and about regularly with me at lunchtime or in the evening, and we’d have a kiss at the end of the evening. Yet she had, I think, lived with Tom for some time. Probably this was simply that she was an open and friendly person and felt I was a pleasant enough companion to go out with. Possibly for situations where we shared an enjoyment in something like the same music which didn’t interest Tom. However on a later occasion she did say to me that when she went out with Tom she was bothered by the way he tended to refer to her as his ‘friend’ rather than anything closer. She also spoke about her parents and said her mother behaved in ways that upset her, and might be unwell. The impression I got was that this meant she found visiting them uncomfortable, and it distressed her. This did make me worry about her. But, when we were together she seemed very happy and we enjoyed each other’s company very much. I didn’t want to push or be a pest, so I was just happy if she enjoyed being with me anything like as much as I did being with her. Came to feel that if she did ever want more, she would say, or ask for help. And I’d have been happy to do whatever I could.
On the Thursday Karen and I took a walk to the Bancroft Rd Library and bought some maps showing the area as it was in 1882. It was strange looking at that map for the first time. It only shows an area a few miles square, but I realised that for most of my life at that time this covered where I’d lived and worked. On Friday the two of us walked down to the Queen’s Head for lunch. I also got a letter from Amhurst in the USA offering me a job there. I still hadn’t really made up my mind about moving to the USA or not, but it was very encouraging to get offers! However on Saturday (25th Oct) I noticed a TV advert for Pan American (airline) as I walked though the living room of our Council flat. I commented that “Everyone wants people to go to America!” to my parents – meaning that the airlines were at the time really competing to drum up business for their transatlantic flights.
A couple of minutes later I went into the kitchen and found that my Mother was crying. She refused to say why, but it seemed clear that she was feeling quite sad about the possibility that I would emigrate to the USA. It is worth remembering that back then it was much rarer than now for people to fly often between the UK and USA. So from her point of view my going to the USA would make her feel she’d never see me again. She never would say why she’d been crying, but this incident, along with other comments I’d had from Chris, etc, did make me consider more seriously that my moving might affect some other people rather more than I’d assumed.
On Thursday 30th October I went with Chris to the RFH. The concert was given by Paul Tortelier and the Mozart Players. Tortelier is a particular favourite of Chris’s. I was continuing to work on my PhD thesis, and not always going to work on the Armstrong amp every weekend because I was determined to finish my thesis by the end of the year. During the week I also helped to test a receiver that was being taken to the Canaries for more atmospheric measurements. On the 4th of November, Nigel Cronin, Brad Rose, and David Adamson flew out to the Canaries with the receiver system to carry out the atmospheric measurements. Their expedition was to last about a month. Judging by the way they took sleeping bags, billie-cans, cold weather gear, etc, they clearly seemed more prepared for the Solar Tower than I was when Ian sent me off to do the earlier measurements from that site. When they arrived, though, they phoned to say it was raining so hard they couldn’t even get up the mountain!
The above shows the view you would get looking East out of the Physics building windows in the 1970s and early 1980s. The field outside was a disused Jewish graveyard. No-one had been buried there in many decades, and no relatives ever visited as they were all long gone. Later on the University negotiated having the bodies moved and the field reclaimed.
During November I started collating information in preparation for a trip to use UKIRT in January 1981. John Beckman had been given time on the telescope and receivers and I was to go along to help run the system. On Saturday 8th November I spend the evening with Chris. She again said she’d miss me if I went to the USA. So I replied that she’d be welcome to come as well. But she said we’d probably aggravate each other! Wednesday 12th, I went to an Austrian restaurant with Karen. She’d initially suggested a German restaurant, but we couldn’t find that one which had a table, so we chose the Austrian instead. Overall, I remained uncertain about which way to head for my future whilst enjoying life day-by-day and keeping busy. I also continued to exchange the occasional letter with Mary Jane or Jennifer Weaver.
Over the weekend of 10-12th November I spent time at East Grinstead with Barry Hope working on the Armstrong 700 amplifiers. By this point I was mainly working on the pre-amplifier, in particular on the ‘moving coil’ preamp stage which is the part that needed to deal with the lowest input signal levels and hence needed to have an ultra-low noise level. By then I was also working on ultra-low noise amplifiers for use by University researchers as well. So the two areas of work dovetailed quite neatly. I came back to London early enough on the Sunday to go straight out to the RFH with Chris that evening. At this point I was beginning to admit to myself that I’d really decided that I wouldn’t be going to the USA. This shows up in a comment I made about Chris in my notebooks after the concert: “I shall miss her if - (note, I’m now saying if) I go to the USA”. The comment in parenthesis – which I did write at the time – showed I was finally admitting to myself that I didn’t really want to go to the USA and lose contact with people I now felt were so important to me.
Sadly, talking to Chris after the concert she’d said that she’d tried sharing her life once and just didn’t want to do that again. I could understand this given how terribly hurt she had been by Steve leaving her. So although we got on very well there still seemed no sign this would ever become more than a close friendship. I’m not now sure when it happened, but as it became clear that I wouldn’t be going to the USA I had a conversation with my Mother which led to her telling me something I’d never known. Since I was now regularly enjoying going out with and getting to know various women it seemed quite plausible that one thing would lead to another and I’d be leaving my parents anyway at some point.
I’d said that I cared a lot for Chris, she clearly cared for me, and we got on so well. But that she simply felt too hurt to be willing to ever share her life again or get re-married. My Mother then said, ‘It takes years to get over being left by someone you loved and married.” She said this with so much certainty and conviction that it was obvious she had good reason to feel she knew it to be true. She then went on to admit that she had been married to someone and then divorced, some years before she met and married my Father! This was total surprise to me. Until that moment – when I was almost 30 years old – no-one had ever mentioned this to me, or given the slightest hint.
Photo of my parents. It shows them in my grandparent’s garden, along with my Grandmother. My Mother’s parents had a flat in the same block as ourselves, with a small but lovely garden.
I knew my Father had been married before. He had never made a secret of this, and it was obvious anyway because I had two step-brothers about ten years older than myself. He still loved the memories of his first wife. When she had been dying she’d told him to get married again because she knew he’d not be happy alone. And he clearly loved my Mother whilst still loving his first wife as well. When he died my Mother arranged for him to be buried beside his first wife in a church graveyard in Laindon, Essex. This was because she’d known this was what he wanted and that he’d gone on loving them both.
My own feeling about life and love is, I think, something that started from understanding my Father and Mother and the example they set. It is possible to love and care for more than one person during your life. And to go on doing so even when they aren’t with you. However love here, for me, means caring about someone else and wanting them to be happy, whatever they may do. or where they go, even if you aren’t with them and miss them. Love and caring makes the prize worth the price. The only real challenge with accepting that you may love more than one person is the test you face of ensuring you never do anything to hurt or harm them. Your love is for them, not for yourself.
However – until she’d made her comment about Chris – no-one had said a thing about my Mother having been married before. She then explained that she’d married a trumpet player who, shortly afterwards, walked out and left her. She had been very deeply hurt by this, and even decades later she still didn’t want to say anything more about it. Indeed, when I made some tape recordings of her recounting her history many years later she continued to refuse to say anything about her first marriage. But she had opened up just to tell me, so I might understand better what Chris would be feeling at the time. She went on to say that, if I cared for Chris and waited, then she might come to feel differently after a couple of years or so. A comment that proved to be well-judged...
On the 26th November I finally finished writing the manuscript text of my PhD thesis. I ‘only’ now had to sort out getting the illustrations drawn and having it all copied and bound for submission. On the same day Carey told me that I was to be one of the Ugly Sisters in the Panto we were writing. Carey had, of course, taken on the arduous task of deciding who was doing what, how, etc, and I for one wasn’t brave enough to argue! A sign of the times was getting a letter from Jennifer Weaver thanking me for sending her copies of the series of ‘Hitch Hikers Guide to the Galaxy’ books which were apparently quite hard to find in Kansas.
During December 1980 I sorted out my flight arrangements, etc, for the trip to Hawai’i to help John Beckman use the UKIRT system. Although I was increasingly feeling that I’d end up deciding not to emigrate to the USA I also tacked onto the end of the trip some flights that would let me re-visit Kansas. On the Wednesday 3rd Karen and I had gone to see a Woody Allen double-bill – ‘Annie Hall’ and ‘Manhattan’. Karen was also helping me to analyse the results from some of my measurements and with getting the QMC computers to plot out satisfactory graphs for my thesis.
|The graph on the left shows some of the results of the measurements made by Jim Birch. The diagrams on the right illustrate two different ways to reduce the amount of loss due to unwanted reflections at the lens surfaces.|
HDPE and LDPE had the lowest levels of signal absorption, so were the ‘best’ choice for lens in optical terms, and HDPE could be machined accurately to the required shapes. In practice, with good materials and machining the main cause of loss would then be a result of unwanted reflections at the dielectric boundaries between lens material and air. For conventional glass lenses used at visible wavelengths the standard approach used to tackle this is to apply surface coatings using a material whose refractive index is different from that of the bulk lens or air. Such a layer has the effect of creating an added reflection interface above that of the original lens. As a result there were now two reflection components produced as the radiation goes from air to lens (or vice-versa). That may seem a perverse thing to do given that the aim is to reduce the amount of reflection, and likely to make things worse! But the idea is to arrange for the reflections to be of equal magnitude but a half-cycle out-of-phase. If that can be done, the reflections add up to zero and the result can be almost no power lost by reflection. Hence the right coating can reduce the overall level of reflection to virtually nil!
Unfortunately, there were no suitable coating materials or methods for mm-wave HDPE lenses, so that approach couldn’t be employed. Instead I arranged for lenses to be ‘blazed’. This meant cutting a pattern of grooves into each surface. The simplest way to understand the effect is to think of the result being that the lens now effectively had two surfaces on each side. One at the tops of the grooves, the second at the bottoms of the grooves. And once again, by giving these grooves the right depth, etc, you can produce two reflection components that tend to cancel out and reduce the overall reflection losses.
The snag with both these tricks is that they tend to ‘tune’ the lens behaviour. So the price of reducing the reflection losses at some wavelengths is to make them much bigger at other wavelengths. But for systems designed for a specific frequency band the process works neatly... provided you have machinists with sufficient skill to accurately manufacture what is required!
On Monday 8th I finished my thesis including all the figures, etc, and the next day I had it copied for binding. At the time Derek Martin and myself were trying to arrange a project with Prof Stradling (not at QMC). This didn’t get off the ground but it was my first contact with him, and may have had some effect on events three years later. On Monday15th December we put on the QMC Panto, ‘Cinderella’, in which I played one of the Ugly Sisters. During this John Beckman and myself sang “I feel pretty”! Type casting, obviously... And on the following Thursday I took my thesis to the binders. Alas, Karen, playing Cinderella, forgot one of her lines which was a shame as she’d been perfect in every rehearsal, and looked beautiful in the dress she wore for the Ballroom scene. Phil Halstead had arranged a big flash for Guy Wilson to appear as the Fairy Godmother – but not quite as big or stunningly dramatic as the one he arranged for me in a later Panto!
The day after the Panto, Derek Martin and myself met Keith Marries of QMC Instruments and they said they’d be able to pay me a salary for a few months at a time to do various project work on electronics and mm-wave optics for them. This would prove to be very useful in keeping me employed during 1981 as I ended up doing quite a diverse set of project work for them. The drawback being that it was on the basis of a patchwork of short-term arrangements, so had no real stability. However given my years in Hi-Fi manufacturing it suited me fine because I was used to designing equipment to meet specific customer requirements, etc.
On Friday 19th December we had a “room party” during the afternoon at QMC with Christmas as the excuse. During this I danced with Karen, Carey, Rosemary Eve, Chris Sutton (Terry Pritchard’s better half), Peggy Rose (Brad’s wife), and Chris Robson. Really wonderful event where everyone had fun. I went direct from the party down to East Grinstead to work on the Armstrong amplifier over the weekend. Chris Adams had left to spend the holidays with her parents who lived in Winchester at the time. I phoned her whilst she was there to see how she was and wished her a happy Christmas. Once QMC was closed for the holidays I spent more time at East Grinstead than usual, focussing on the pre-amplifier sections of the 700 design. Then home again to spend Christmas and New Year with my own parents and family.
23rd Aug 2017