Saturday, 22 September 2018

VHF, 1970s style.

I have been away, in Norway this time. Here is the usual photo of me somewhere unexpected ....
I was only on Honefoss platform because of a landslip on the track, and the Oslo to Bergen train had been diverted over a freight route to bypass the problem. This then led to us missing some stations and we then had to wait at Honefoss for buses to bring along the stranded passengers. After some shunting, the whole effect was to make us a hour late. Many UK rail travellers believe that such things only happen here. Thanks to a passing Australian tourist for taking the photo.

Anyway, I was going to say something about the radio world I joined, and how different it was from now. Sorry it is too long, but I cannot make it much shorter. Any errors are my fault, I am relying on an over-stuffed memory.

1) The Licence
I was first licensed as G8JWG on 4 February 1975. That was an "Amateur (Sound) Licence B"  which only allowed operation above 144MHz. I had passed my City and Guilds Radio Amateurs Examination, which was one part of the process, but I had yet to pass the Post Office morse test, which involved sending and receiving 12 words per minute morse.

I could only move up to an "Amateur (Sound) Licence A", which covered all permitted amateur bands, once I had passed both the exam and morse test. Some people waited until they had both and went straight to Class A. Others, like me, did the exam first and then learned the morse. The exam pass lasted indefinitely, whereas the morse pass was only valid for a year. If anyone had not applied for a licence within a year of passing the morse test they had to pass it again, which they also had to do if they later let their licence lapse for a year or more. On the other hand, once you had a Class A licence you never needed to do a morse test again for as long as the licence remained valid. It seemed a bit barmy that a morse test pass was only valid for a year, whereas if you could get a Class A licence, never use morse again, but still be regarded as proficient for as long as you paid your fee every year (which was exactly what I did).

The Class A and Class B thing was a clear enough system then?

There was a strong incentive to do the exam first and the morse second, as then the exam pass could not expire while you waited to pass the morse, whereas the other way round the morse pass could expire waiting for the exam pass.

You had to pay a fee every year. More than one for me actually, as in addition to the main Amateur (Sound) Licence B, which was then £3.00, I had an Amateur (Sound Mobile) Licence B which cost £1.50. The fees soon doubled. You had to renew each of them every year, and they kindly wrote to you telling you the time to pay had come. You then posted them the money and they sent you a receipt through the post, stamped "PAID" by the Cashier of the Home Office. All very formal and there was no Paypal in those days. You had to be careful as not only was illegal operation actually pursued in those far off days (which is not the case now) but if you had a Class A licence and you let it lapse for a year you would have had to retake the morse test.Taking it once as bad enough, taking it again would have been terrible for me. Actually managing to pass it twice was probably impossible for me.

Then, not only did I have my licence, and my mobile licence (I never had the television one to make up the full set - that came with an additional callsign too), there were all sorts of other bits and pieces. When I moved house and potentially had two possible operational locations, one had to be signed G8JWG/A. You needed to write to the local Post Office engineer and get approval to use a /A address. As usual click on the photo to enlarge if necessary.
When eventually "hand portable" equipment became available (in my case a 1 watt Kenwood TR-2200 which weighed 1.7Kg and needed a neck-breaking shoulder strap) you needed permission for that too. Given the quality of the equipment available and the capacity of the batteries of the era it was barely a practical idea anyway.
This was in the era before mobile phones, a time when anyone walking about the streets talking to someone far away was likely to be thought to be mentally deranged. There was, however, a further oddity. This portable operation was an extension of the mobile licence so you used your callsign /M, which seemed a bit odd being portable. /M meant mobile, or at least potentially mobile, be it in a car or on foot (but never in a bus, which was specifically banned). /P (for portable) did not mean what we all thought portable would mean, /P meant in a field, or by their definition somewhere without a postal address. If it had a postal address it was /A (for alternate) anywhere other than at your registered station address. But woe betide you if you used the wrong one, for there really was enforcement!

Slightly strangely, if you were not earning enough money to run a car and decided to operate pedestrian mobile instead, you had to spend some of the money you didn't have to buy a mobile licence you wouldn't use in order to get a piece of paper to tell everybody that you were not a madman but a radio amateur.

The first licence I had was that, then standard, Amateur (Sound) Licence B, the one with the specific ban on using spark transmission. If the use of spark seems improbable even in 1970s, it hadn't long died out for ships lifeboat emergency sets. When I worked in a photographic shop we sold remote shutter releases operated by spark transmitters. Am I really that old? Wot, no Bluetooth enabled 35mm cameras then?

In February 1977 the Home Office wrote to me and advised me that I could now have an Amateur Radio Licence B instead of an Amateur (Sound) Licence B. I was told that this would give me greater flexibility and I would now not need two licences (one Sound, the other Sound Mobile) plus two letters authorising use at an alternative address and pedestrian mobile. Also gone was the requirement to get the approval of the local Post Office manager for /A operation (you only had to notify them instead). Hurray! The price went up so that the one licence cost more than two previously. Such is progress.

I would love to show you the original licence but the Home Office insisted on me returning it before they would send me the new one. I think this shows how important the actual bit of paper was in the days before electronic communication. Somewhere I hid the mobile version as I only sent them the main one back, but right now I cannot find it.

The Home Office sternly advised me ... "Be sure to read the clauses concerning calls signs and log-keeping". I mention this because nowadays suffixes such as /A, /P and /M are no longer even a requirement, now they are just a recommendation. You don't need to sign /M any more, and generally I don't after establishing contact. Nor do you need to keep a log except under specific circumstances. At least this new licence had shifted pedestrian mobile into portable, which seemed more sensible at the time.
Debate about the difference between a "temporary location" and "alternative premises" was to dog the hobby for years. So was the requirement to use your callsign every 15 minutes and when changing frequency - people still do even though this is no longer mandatory. It just shows that we amateurs have our own rules over and above those imposed on us. Try giving out an address when you contact every station, every 15 minutes and when you change frequency.

The logging requirements were very onerous. Although the new Mobile licence clarified mobile logging in the sense that it made clear that you had to log everything as soon as possible, you still had to log everything. Everything included CQ calls and the many tests using the frequency testing equipment you had to have (and there was a page in the licence devoted to that), mobile or not. Think of it as using today's contest logging, but on paper, and if you were rash enough to go mobile you had to recall it all and write it down later.

It was really very bureaucratic, even with the "flexible" new licence. You trifled with it at your peril. There were station inspections (the unit who did this have been more or less disbanded so there is not much chance of it now). People listened and on one occasion I received a very odd telephone call from a Government employee in the radio department which proved that.

2) Class A licence.
I really wanted to get my Class A licence, at least in part because I had heard about this 4m band thing and I also heard a rumour that there was more to VHF than 2 metres. So I had to learn morse and reach 12wpm. I did this with the help of Eden GI4AIO and Dave GI4CWZ. These people took me in and spent time training me. You had to go to them - the Class B licence did not allow you to use morse on the air to reach proficiency. You were banned from sending CW on the air - even though you only had a VHF licence which did not require morse proficiency.

There was a large band of people keen to tell you that because they could do morse easily, you should find it easy too. This was rather like people telling someone with dyslexia that he ought to read the rules they had drawn up. But wait, those people still exist and still think that their fortunate ability to do CW should apply to everyone. It doesn't. It never did.

I did listen to weekly slow morse (from GI3SXG I think), but of course that only covered receiving. As it happened, my sending was fine, it was the receiving which needed attention. I also had some morse records. These were 12 inch vinyl records which you could play at various speeds, 33, 45 or 78 rpm as your speed increased. The drawback was that the tone of the morse changed when you changed the speed, and so did the spacings. It was tedious, but it had to be done.

Eventually I applied for my morse test. Some of my contemporaries had hit on the idea of heading off for Lifford in County Donegal where the Republic of Ireland post office examiner was very co-operative. I never heard of one of them who did not pass first time. I, on the other hand, being more principled and not wanting to spend the money on the 200 mile round trip, opted for the UK test. This took place at the Custom House in Belfast. I won't mention the examiners name, and the pass certificate was not issued by him personally so it has a different name on it.

The gentleman in question was a marine telegraphy examiner. It was pretty clear that English was not his first language, which might have helped me in the end. For whatever reason we didn't exactly form a natural conversational duo.

He gave me some character groups and let me practice on his morse key to get accustomed to it. He told me to try the whole script twice, which seemed odd. Then he started the test with the same script. This seemed even odder to me, as I had already got used to it. While I was sending he was signing a large pile of pink expenses claims and nodding regularly. Anyway, that seemed to go OK.

Then he sent to me. I still have the copy I took down, written in the faint pencil he loaned me, scrawled on a small square of lined paper. I won't embarrass myself by showing it here. "Read it back", he barked. I got on fairly well because he had asked me to read it back. I corrected a few mistakes which he would have found if he had read it himself. Then I got stuck.

"THE - missed a bit - SAMR ICANH" I stuttered.
He peered at me
"Doesn't that say THESE AMERICANS"? he grumped.
"Yes, I think it does" I replied.

I knew I had blown it but I carried on. I finished and at first he kept silent. Then he leaned towards me and grabbed me by the arm:-

"Tell me this is for amateur radio" he barked
"Yes it is" I said, a bit confused "I booked it for that"
"Don't ever let me find you at sea with that performance" he growled
"Oh no" I confirmed
"If I ever find you on a boat, I will throw you over the side. Your morse is terrible"
I nodded. It was true. My nod was my acceptance of his assessment. I would never make a marine operator, not that I had ever wanted to be one.
There was a long pause.
"In that case you've passed" he said.

That was that. The marine morse test was far harder and entirely different, so I still do not understand what he was on about. I have wondered ever since if perhaps his thick accent or my thick accent caused some confusion.

It is possible, allowing for the couple of corrections I made which he did not see, that THESE AMERICANS was within the allowable error limit (I missed three letters and got the spacing confused). Years later I recalled that I sent him letter and number groups of five characters, but he sent me plain text - I never even noticed that at the time. I guess because the slow morse I had been listening to was plain text I thought it was normal. The numbers were in random groups of five. He never even looked at my copy, but relied entirely on my smoothed out spoken version of it.

I had passed. My immediate CW career went on to see me work one station on 2m, one on 20m and I did not have another CW QSO for more than 25 years. I still have this man's assessment of me playing in my head.

At least it saved the petrol money for the trip to Lifford. The UK standard was, well, possibly on a par with Lifford. I did not sneak across the border to a foreign jurisdiction to gain a questionable pass certificate.. Oh no, I earned my questionable pass certificate by bungling my way through the oddest test I have ever undertaken, right here in the UK.

Later I received a certificate, signed by somebody else, and after that I also received through the post something called  a Radio Amateur Certificate and eventually a Class A licence covering all the amateur bands. I still wonder quite what all that was about.
Hmmmm. Apparently I had passed.
I immediately framed my Radio Amateur Certificate and proudly put it on the toilet wall - I never did find any other purpose for it. Then I had to wait to see what callsign would turn up.

Both of my callsigns were simply allocated to me. You had no choice, though a few patient people waited without a licence for a "better" callsign to be reached as they progressed alphabetically through the list. So I had been first been allocated G8JWG, which I disliked. It was awkward to say due to the W in the middle. I supposed that G8JUG would have been worse. Second time around I got GI4FVM which was better. I might have got GI4FUM, and becoming that would have been terrible.
At last I had my Class A licence.
There was a clause in the second licence which revoked the first one. I have never understood why people need more than one callsign in any country. It just seems to me to confuse things, befuddles the QSL bureau, and prevents the official number of licences issued figures from accurately representing the number of amateurs. Anyway, the only re-appearance of GM8JWG is the odd occasion when he spots GM4FVM on the cluster.

With GM4FVM being a "full" licence I could apply to operate in some other countries. Only some, as a only few had reciprocal arrangements, and some others would accept a UK licence as qualification for one of theirs. In those days the Republic of Ireland authorities required all their amateurs to provide them with details of the radio experiments they intended to carry out. Of course they required that for their "visitors" licence too, so for several years I had to set out the technical aspects of what I wanted to do, attach the required drawing, and back came this ...

3) Equipment and Operations "pre-transceiver"
When I started working on HF this was simple. The modern concept of the transceiver had emerged in the 1950s and by the late 1960s and it had really taken hold. Most HF operators had abandoned their old separate transmitters and receivers and gone over to SSB. The secondary bonus of  the transceiver was that you automatically transmitted on the same frequency as you received (the primary bonus being that it shared components as was thus cheaper than the separates). People rushed into the more efficient SSB and almost everybody was on the same frequency on transmit and receive.

There were,  of course, some HF old timers who refused to modernise. They often used surplus gear, with crystal controlled CW or AM. The use of crystals meant that they had fixed transmit frequencies and thus usually worked what we would now call "split". There were AM nets, who were theoretically on the same frequency, but this was pretty approximate. SSB required much better frequency stabilisation than AM.

Manufacturers offered matching transmitters to ease the pain of converting. If you had a receiver you could add a transmitter and share the VFO, which at least brought you onto the same frequency. If you had different types of tx and rx but you had a separate transmitter with a VFO and you wanted to get onto the same frequency then you could transmit a weak "netting" signal and tune your tx frequency until you could hear yourself in your receiver. It was not a very accurate way of doing things which was fine on AM but did not really work too well on SSB. It was tricky on CW. I still recall hearing netting signals before stations called me.

However, although the HF community had jumped into transceivers made by Drake and Collins, there was nothing similar for VHF. I used to visit the City of Belfast YMCA radio club in the late 1960s and early 1970s. Their pride and joy was a KW 2000, a lumbering beast of a thing. No doubt, as an SSB transceiver it was cutting edge for its time; to me it seemed vast, heavy and unyielding. Later as Chairman of the Queens University of Belfast Radio Club for several years I used their Yaesu FT-200 which was a joy in comparison - but still heavy (7.6kg). The arrival of radios like the FT-200 and the ground breaking FT-101 changed something very important - they were affordable. It was the end of an era. The day of the HF SSB transceiver, however clunky at first, had arrived. For VHF there was nothing like it, so we muddled on.
Yaesu FT-200. About 60% of the price of a KW2000 and better all round. Photo rigpix
In VHF the world was very different in the late 60s. It was as if the transceiver had never been invented. Leaving aside SSB pioneers, the traffic later carried by FM repeaters was almost all on AM. By the time I was licenced the RSGB had produced a bandplan which was rather like a simplified verison of what we have now. Previously there was a regional bandplan for the 2 metre band. It looks very odd now, but it seems to me that the object of the Regional Band Plan was to bring together stations rather than keep them apart, as is the case now. At some time there must have been so few VHF experimenters that something was needed to let them hear each other.

The thing was, in the absence of new equipment, and given the well known reluctance of many amateurs to even consider keeping up with progress, pretty well everybody was still using the old regional band plan. The  home brewers probably did not want to go back to the drawing board and the users of commercial equipment quickly found that there simply was nothing suitable available apart from their cast-off ex-PMR taxi radios.

Thinking first about the more local traffic, there was a marked difference between London and "the North". In London the 2m band sounded to me like HF must have sounded before the arrival of the SSB transceiver. There were lots of AM stations, added to by a growing number of FM ones, scattered about an "all modes" section. The one thing which almost all of these had in common was that very few of them had more than one frequency to transmit on.

This seems very strange now. When I bought my second hand (used) 2m transmitter (I think it cost £11.00) it came with three crystals. That was my entire range of options for frequency selection. I see from log that I used 144.365, 144.770 and 144.950. Everybody else had different crystals and nobody really seemed to be on the same frequency. One joy of it was that your crystal seemed to give you personal use of a specific frequency - the downside being that nobody else was there. This was very much how things used to be on HF years before.

If 144.365 seems very close to the SSB "calling frequency", in those days the new band plan allocated SSB calling to 144.200 and described the upper end of the SSB section as "flexible", whatever that meant. With that fudge everybody could go on as if the new band plan did not exist. My 1974 "NBFM Manual" outlined the benefits of FM and showed the new band plan, but nobody seemed to care about either of these things.

The drill was that you called CQ for a long time on the one frequency you had in the hope that somebody would happen to be tuning past on their receiver. If they heard your call they would also hear you say, right at the end of your call, "tuning the band from high to low", or "tuning the band from low to high". If they only had one crystal, and many did only have one, they would give you a long call and hope that you would tune past them and find them before you had found somebody else.

Of course, I had the unusual luxury of three crystals. If somebody was calling CQ and said they were tuning from high to low I could select 144.95, which they were likely to find before 144.77. If they were tuning low to high I could select 144.365, and hope to get in before somebody else. As everybody was working split it meant that every QSO occupied two parts of the spectrum, and listening to both sides of a QSO involved me in a lot of VFO spinning. In a net of three or four stations you would find them all over the band. I have some cassette tapes of all this going on, and it is mayhem.

One reason why many people only had one tx crystal was that they were using ex-taxi type surplus mobile radios. These usually only had one socket for a tx crystal and one for an rx crystal. A company called Garex sold a conversion of a PMR radio which had a frequency tunable receiver while retaining the crystal controlled tx. This beast had a vernier dial for the VFO, but the receiver was not very stable anyway. These old PMR radios were amazingly bulky and crude. Brands like Pye, Cossar, Bundept, Storno were common.
I used a single channel version Cambridge on 4m. Photo: Pye History Group

Whilst by that stage the PMR users such as the fire brigades and the police forces had gone over to transistorised gear, the surplus we had was their previous generation of valvised equipment. These had been discarded for all sorts of reasons but made fairly good fixed stations. Older ones were entirely valvised, later ones were hybrid designs with a valve in the final transmitter stage.

The downside of these pieces of equipment must have been the trembler power supply. They were designed for use with 12 volt car electrics, and early ones had a simple buzzer-type circuit which cut the car's DC voltage into a square wave to feed to the primary winding of the HT transformer feeding the valves. Although later more efficient transistorised inverters were introduced, this was still fairly inefficient for amateurs who found access to high output power supplies tricky. Converting from mains AC to 12v DC at high current was hard enough with the technology of the day, but when it was then chopped up and converted back to high voltage AC and rectified and smoothed into DC you were really wasting a lot of energy in the process.

It must have been clear that this "tune the band" system was never going to last much longer but you would not have thought so. The 2m band was full of AM stations using two frequencies to work each other. FM was easier to generate than AM, and more efficient to amplify to useful output power levels. Repeaters were on the way, and with that would come an era where people used dedicated amateur gear rather than PMR cast-offs. It took time though, and many said that they would never change.

Of course, you did not have to use ex-commercial surplus equipment, You could build your own, and many did. There were one or two commercial products. TW made a range of transmitters and receivers for the amateur market, including some transceivers which were a receiver and a transmitter built into one box. Then there was the one I had - the EMSAC TX2 (there was also a TX4 for 70MHz).

Away from London things were simpler but also messy in a different way. "The North", where I ended up, seemed to include everywhere from Northern England to the North of Scotland and included the Isle of Man and Northern Ireland. As we shall see later, many people in the North avoided the tricky issue of crystals and tuning by using the same AM frequency and avoiding new-fangled FM entirely.

That was the local traffic. VHF Dx-ers had virtually no commercial equipment available.When you think about it, dx is generally across regional boundaries and that meant crossing the regional bandplan areas too. Thus you had to work split or break the band plan rules.

The options for SSB were limited. In the early 70s basically you had to use an HF transceiver and a transverter. You could build a transverter or they were available from makers like SSM (later to be SEM). These things were essentially like the receive converters we used on AM but with the local oscillator frequency tapped out and used to mix up the SSB transmitted signal to 144MHz. I mention this because some of them actually had the receive converter (still in its box) attached to the back of the case. The final output stage then was a valve, usually a QQV 06/40 producing upwards of 50 watts.

There valve transverters were potent things indeed. I had one. Usually they relied on the HF transceiver for their high voltage to apply to the valves. Most Japanese HF rigs had a socket like an octal valve base which allowed you to extract the high voltage. Later I also had a Yaesu transverter which went further and was even styled to matched the FT-101 I had. This one made it possible to just turn a switch and move between HF and 2 metres - what a luxury. And this transverter had a transistorised final stage, though only 20W output.

The obvious problem with transverters is that they required you to have an HF radio to drive them. An HF radio involved a very large cash investment for a Class B operator who could not use it for HF. Even for those who could, the HF radios of the time were not very suitable for general 2m use as they lacked FM, did not have the ability to work split frequency and many older ones had no provision for a low power output to drive a transverter. Lacking an alternative, we still did it and made everything work somehow. If you did not have the money, or the determination, or the knowledge, you were stuck with AM and either split frequency operation or the perils of using the single AM mobile frequency.

4) Equipment and operations "post transceiver"
There was a time which I can well remember when 2m (which was all of VHF for most people) lived like a hangover from the 1940s, with valve equipment, fixed crystal frequencies, split operation and a rather hit and miss CQ system. I see that in my AM/FM only days in 1975 I worked stations using many Pye Cambridges, Pye Vanguards, and even a 90 watt Pye Base Station (probably the one out of the dire but homely TV series "Dixon of Dock Green"), all ex commercial. Apart from the Base Station, nobody was using more than 10W, many a lot less.

One station then was using a Heathkit HW17 valve "transceiver", another variant of Garex's idea of a tunable receiver with an unrelated crystal transmitter. About a quarter of them had homebrewed the tx but used commercial HF receivers with VHF converters. Somebody was using an ex-Navy B40 receiver with a homebrew converter. The receiver alone weighed 46Kg, as much as I weighed myself in 1975. One station (G6QN) told me that he was first licensed in 1922. He must have felt at home.

Although it was a joy to operate in what was really a radio museum, this had to end sometime. The regional band plan had been officially replaced by 1974 (though clearly it took a while for anybody to notice). The arrival of receivers that weighed less than a young radio amateur, the appearance in amateur circles of reliable transistors for output stages, and an influx of remarkable compact, cheap, Japanese gear changed everything. The change was really product led rather than any effort by amateurs to modernise.

Probably the first thing that most people noticed was the appearance of the Belcom Liner 2. This appalling excrescence was in fact an SSB CB transceiver with a 144MHz transverter, all bundled into the same box. It was a true transceiver, and it ran about 7 or 8 watts of SSB, so it was immediately transformative. It came with the standard cranky CB-style VXO with stepped frequencies. With a bit of twiddling you could tune right onto somebody's frequency, which was a novelty at the time. It arrived before the end of the Regional Band Plan so the supplied coverage of 144.100 to 144.340 was no use to those unfortunate enough to live in "the North". Modified ones were available for us, but then those ones shared no common frequency with ones used in other regions. Those sticking to the old Regional Band Plan, which was already doomed by the possibility repeaters, were going to have to get up to date.

I have a Liner 2 here. I never owned one years ago, so I bought one from Derrick, GM4CXP for "old times sake". I get it out sometimes and look at it. It is awful. This is a "Northern" one, so the frequencies are wrong for the current band plan. I seem to recall that 145.41 MHz was the Northern SSB calling frequency. I wouldn't use it now anyway so it stays the way it is.

The Liner 2's great plus (the transistorised output) was also its weakness. Already operating at the limit, the final could not take any more. People realised that the Liner 2s audio stage was uncompressed and thus its average output was low, so they turned up the drive. Bad idea. Although the talk power went up, the Liner splattered all over the place on speech peaks. Sure, they were fine if you left them alone, or so the story went. Better still was to add a Datong RF speech processor (I still have one of those too, this time my own one from 1975), but then if you used one on a Liner 2 you just overheated the output transistor and it died anyway.

For those who treated them well the Liner 2s were a joy. People climbed hills, put up aerials, and actually came on the band. Distance records were broken, and 2m had come of age. How come? Well, the Class B licence helped to get the numbers up, but freeing people from the necessity of owning an expensive HF radio and a transverter too was key.

The Liner 2 cost £151.80 from Lowe's in 1973, which was 5.5 months pay for me. I might have afforded one if I had been prepared to go without food for 5.5 months. I never had one then but it changed the face of VHF operation.

By comparison, the FT-200 transceiver was £159.00 at the same time, so the pathetic Liner 2 cost as much as a very competent 100W multi band HF rig. An SSM transverter cost £79.09 and suited the FT-200 perfectly, so a much more effective solution existed if you could afford it. Nevertheless, the Liner 2 was still the most portable thing around. It was years before Icom, barely functioning when the Liner 2 came out, produced the rig the Liner 2 should have been, the IC-202. But that is another story.

Briefly there was the Braun SE600. This was a majestic radio, an attempt at a multi-mode VHF transceiver. It still had a valve in the final stage (!) and about 20 watts output on SSB. It looked like a piece of lab equipment and with a digital readout (gosh) and two VFOs it cost £627.00. The Liner 2 cost the price of an FT-200; the Braun cost the price of four FT-200s. I don't think they sold many but it was a bold view of the future.

On the transceiver front, the mainstream Japanese manufacturers were not far behind Braun. By 1975 my notes record a few, a very few, stations using rigs like the Yaesu FT-220 and the Trio TS700. These were the first mass produced VHF multi-mode transceivers we had seen. They included FM and moderately stable VFOs. By modern standards their output power (10W), receiver sensitivity, and strong signal handling characteristics are not great shakes. But at the time they offered a real step forward. They came with repeater shift - the first UK repeater GB3PI arrived with an experimental service in late 1972. Within 5 years most UK amateurs were within range of a repeater. My first repeater contact was via GB3LO on 18 March 1975.
The Yaesu FT-221R. How I would have loved one. Photo rigpix
Later the Queen's University Radio Club had a Trio TS770 which included 70cms - now that was a shock. Even the basic TS-700 was well beyond my pocket, as was the Yaesu FT-220. I really loved the look of the 220 and the later 221, and its VFO. I still find it a pleasing design but there just was no money for it. I decided to go down the transverter route because I already had an FT-101 to drive one.

Briefly, before the transverter I had one glorious period with an SSB mobile rig. Not wanting a Belcom Liner 2, I bought the mainstream answer to it, the Trio TR-7010, as soon as it was released. It was an SSB/ CW transceiver. I had joined the modern world at last. I could operate on the same frequency without problems and run to the dizzying heights of 8 watts through its transistorised final stage. It was magic and there was lots of SSB mobile and fixed operation to follow.

On the local AM/FM front, things were changing too. Tuning the band in either direction was not easy while you were mobile. In my part of "the North" everybody stayed on the mobile frequency of 145.800. This meant that all the local traffic, fixed or mobile, in half of the UK was on one AM frequency. There were always multiple QSOs going on. There were heterodynes all the time. As you drove about you found yourself in the middle of somebody else's conversation and neither of you had an alternative frequency to use.

For most people 144.8 AM was VHF, end of story. How wrong they were.

The rig that caught the mood for local operation was the Inoue IC-2F. It helped that is was more or less the first of its type available in the UK. It was a compact FM transceiver equally at home mobile or in the shack. It offered 6 crystal controlled channels and 10W output. Compared to a Pye Cambridge this was an object lesson in miniaturisation and efficiency. It actually had a knob on the front which you could turn and change both the receive and the transmit frequency (fancy that). It is difficult to describe how revolutionary a radio like the Inoue IC-2F was, and it was quickly followed by Yaesu's imaginatively named FT-2F and many others.
Inoue IC2F - a game changer in a modest way Photo ik3hia
By 1975 I had worked someone using an IC-2F and visited someone else who used one. I was already converted. Inoue changed their name to Icom and started developing a series of VHF base station rigs which quickly progressed to the IC-201, a remarkable bit of kit which competed in the multi-mode area with Yaesu and Trio (later to be Kenwood in the UK as it already was in some other areas).

Having heard about the Inoue IC-2F I knew I had to do something as single fixed tx frequencies and separate receivers were quickly becoming obsolete. My first (mistaken) reaction was to obtain a modern transmitter, as I already had a receiver. I was still thinking in terms of separate tx and rx. The tx I bought was something called a Telford TC9. This was an FM transmitter with a VFO. I would still have to net in, but I would be freed from crystal control. It didn't last long as the internal power supply blew and took everything else with it. That was a pity as it had a very nice Eddystone-type slow motion drive. I did try a VFO kit for the EMSAC. It worked, but was hopelessly drifty. 

Eventually I caved in and at the end of 1976 I bought a Standard C-828 Japanese FM transceiver and went channelised for FM. I never worked AM on VHF again. The Standard 828 was a fairly novel thing as it used the same crystal for receive and transmit - useful at a time when crystals were so expensive to buy. Later I also bought the optional VFO which ... also ... turned out out be hopelessly drifty. This was the factor which caused so much trouble then. Before phase lock loop technology nobody really cracked it. I am still using the Standard 3 amp power supply I bought with the 828 in 1976.
Standard C828 Photo rigpix
Soon everything had changed. Within a couple of years we had given up tuning the band and separate receivers. We arrived at channelised working, transistor output stages, repeaters, a unified European Band Plan, multi-mode VHF transceivers (even if I couldn't afford one), compact mobile rigs ... modernity ... in a very short period. These days I might be surprised if someone turned up on the doorstep wanting to inspect my equipment, but in 1975 I expected it to happen any day.I knew someone who had his licence suspended after such a visit. It was a worry. However, we all got on with it and tuned the band from top to bottom.

There are still some dunderheads who, 45 years after the frequency was allocated for other uses, still operate AM or FM simplex on 145.800. Other, more sensible individuals, try to rekindle their memories by refurbishing old radios from this era and they get much satisfaction from doing so. I personally would like to just remember how it was and move on. I prefer to use modern equipment in a modern way. Each to their own. However, I still remember the complex licensing, the separate transmitters, the valves glowing purple and the whole rather primitive nature of it all.


P.S. I do not know whether bandplan is all one word or two, so take your choice from the above.

Sunday, 2 September 2018

Equipment, autumn and the Microset RU432-95 linear amplifier

Now that September has arrived we can start to think that the Sporadic E season is almost over. There may well be several good days for Es during September, but the regular openings are usually over by this stage of the year.

I tend to take a spell off from radio sometime around now, though that generally means that there will be a brilliant tropo opening which I shall miss.

Trigger for this change of mood is the harvest in the field outside the shack. This year the weather, which has been very dry at times, has brought the harvest forward despite the wheat having been sown late. The dry season has also resulted in unusually high demand for fodder, raising the value of grass hay bales. This has, in turn, created more of a market for the lower grade straw cut from the wheat fields. Usually the straw is left to dry and collected long after the wheat has been harvested, but not this year.

The harvest turned into a dramatic dash with 7 machines at work at once - and 432MHz being obliterated by various signals, intended and unintended.
Harvester hard at work outside the shack
Straw bales being removed immediately by Manitou reach stacker
This seasonal change marks an alteration in the nature of the radio here too. For me, meteor scatter and tropo become of more interest. However, the pace generally slackens and I have other things to attend to.

Time for a review of the equipment.

A few months ago I bought another Icom IC-7300. This came second hand (used), was installed and after that I basically put it into use and have nothing further to remark on ...
IC-7300A (left) and the original IC-7300.
The large gap between the two radios was filled, until last week, by the control box of the IC-7100. However, with the general reshuffle the IC-7100 control box has moved to the other side of the desk. On reflection, I may move it back between these two.

End result is that the FT-817 is not in regular use.

Things are now divided up as follows. The two IC-7300s cover 4m and 6m. The TS-590 drives the transverter on 2m. The IC-7100 does 70cms. Any of the radios could cover HF, but that duty presently falls to the IC-7100. Well, it does in so far as I do any HF.

Another second hand purchase has been a Microset RU432-95 linear amplifier. This thing is capable of about 95W output. I tried to photograph it in position, on a shelf in a dark corner, so sadly the image is rather grainy and of poor quality.
Microset RU432-95 linear with sit-on fans and temperature controller.
It currently has three fans sitting on top. This may appear rather excessive. Two are there under the control of a thermostatic switch, the same system as I have on my 6m linear and my 2m transverter. The third one is controlled by the sequencer to activate during transmit only. I tried both systems separately and they worked OK, but having the linear hidden away at a distance made me uncomfortable. Plugs and temperature sensors can pull out, and it would be easy for it to overheat. So I have two independent cooling systems.

Not that this particular linear looks to be liable to overheat. It shares the same size box and heatsink with the SR-200 I used for many years on 2m. It ran 200W, this one runs 95W, so the heatsink looks well able to handle the heat. So far that seems to be true, though it is still early days. I am not yet sure how it will behave during a contest or a long 70cms opening, so I am playing it safe for now.

I dithered a bit before buying the Microset. First of all - do I need a linear on 70cms at all? Then, although the Microset looked like a good bet based on my experience with the SR-200, it seemed far too expensive new. I watched this second hand one for a month to see if the price would fall - in fact all that happened was that it was offered with free postage, which is a price reduction in a way. Eventually I decided that I had waited long enough.

I think that most of you know about my approach to equipment by now. I do not go in for expensive rigs, free-standing masts or full-legal linear amplifiers. Instead, when I want to extend things I tend to upgrade to a modest level - or, in the the recent case, go for a new band (70cms). Thus you will not find a 4 yagi stack here on 2m. On the 70cm linear side there are much more powerful linears at twice the price, and some smaller ones which offer little progress over barefoot. The only other one in the 100W-ish range is from RM Italy. I know that RM Italy have improved their designs, but the Microset seems better constructed to me. There is also the issue of the drive level - the Microset suits my equipment better. The RM linear has a very low drive level, and I know that my IC-7100 puts out a spike on starting to transmit which might overdrive the RM.

So a second hand Microset it is. Second hand is what made the difference. It saved me over £200. It brought it within my affordability limit. Buying second hand equipment comes with a certain degree of risk. However, I have bought an IC-7300, a TS-590, a TE Systems 6m linear and this Microset all for prices I could afford.

If they fail then they fail, and I have not lost so much money. It is a risk I am willing to take. I know for instance that this linear has already been back to Microset in Italy for repair before I bought it. Life is full of risks. I had looked long and hard at older BNOS linears before concluding that this was the way to go. Time will tell.

One downside of buying second hand is never knowing quite what you are going to get. This time there were no instructions, circuit diagram or PTT plug. I must search the internet to try to find instructions or circuit diagram for a Microset RU432-95 linear amplifier. As for the PTT socket it is a "Molex"-type 2 pin. As this is the same as the SR-200 I was able to improvise to start with and order a new one. To my surprise, these could not be found in the UK for a reasonable price and I had to wait for some to arrive from China.
The 2-pin "Molex" plugs had to come from China.
I suppose I should not be surprised. The days when "Eddie's" shop across the road from school contained any plug I might need, or if needs be I could visit Smithfield market where surplus stores sold everything from Post Office relays for 5 pence to entire receivers for £2, are long gone.

I did take the time to tidy up a bit on plugs and sockets. The SHF-Elektric Bais-Tee and masthead pre-amp both use phono plugs as DC connectors. I have to use them there, though I always short them out trying to connect them (try turning the power off first, Jim). Then again I have been using phono plugs for the same purpose for my cooling fans. Phono plugs are just not suitable as DC connectors. But what to use? Even more surprisingly, the 2m pre-amp uses a PL-259 socket for its DC supply socket. I prefer to restrict the use of phono plugs to PTT leads, but here the Microset uses Molex connectors for PTT when you might think they would be better for DC. Banana plugs are awful, so maybe spade connectors and screw terminals rule. Anderson power plugs seem rather over the top to me.

Anyway, I am still sorting out the 70cm set-up. I have moved the radio section of the IC-7100 to be beside the Microset linear. This saves 4m of RG-213 coax. I could not see the point of having a radio which allows the RF section to be separated from the control box and then not moving the RF section as close to the antenna as I can. This is especially true for 70cms. This has created a "70cms outpost" at the far side of the shack, with the IC-7100, sequencer, linear, fans, SWR meter, the Bias-Tee and a PSU all located at the end of the Hyperflex coax. This is worked remotely from the IC-7100 control head. It saves using any RG-213 coax (except for a short length on the mast). If I had another 2m of Hyperflex I would get rid of that bit too.

That seems to be plenty to report on the equipment front for now.

With the 4m allocation to Germany coming to an end this year on 31 August there have been many German stations to work, especially on meteor scatter. 28 August brought an unexpected tropo duct opening into Switzerland. I worked HB9MFM  and HB9DFG on 2m (both JN37 - 1162 and 1138km respectively). I took the whole thing rather casually as I knew I had worked HB9 on Earth-Moon-Earth. Except that I hadn't. HB9 was a new country for me on 2m. I think that I spent so much time listening to HB9Q on EME that I convinced myself that I had worked them.

This was a classic duct opening. Apart from one or two stations in England I could hear nothing apart from the two Swiss stations. Actually, nothing was worked here for more than 4 hours on either side of those two contacts. I can see why ducting is very localised, but why "normal" propagation seems to vanish at the same time is something which puzzles me. Perhaps this doesn't happen. Perhaps I am just not seeing things logically.

HB9MFM was heard here for over an hour, mostly calling CQ and working nobody. There did not seem to be any other GM stations active, or else they were out of the area fed by the duct. I felt a bit for the Swiss stations when I heard long calls and no response.

I have now got to 27 DXCC on 2m excluding EME. EME only adds one more not worked directly (Bulgaria).

I am still mystified by all this tropo success.