Last edited 01/04/2003
As a youngster, I recall listening with envy on hot summers afternoons to people out on hilltops around the country using Liner 2s (perhaps the first generation of commercial 2m SSB equipment). To me it seemed to be the ideal way to operate, out in the countryside on a sunny day. In the 25 years since then I have often thought back to those days and wondered if that idyll was actually achievable. Of course, its easy enough to cart a radio with a battery up a hill but I had a rather different idea in mind. I wanted the radio to be a complimentary activity rather than the main reason to be out in the countryside. This immediately demands a complete rethink on the sort of radio operation that is practical. The radio equipment needs to be small and light enough to be put in the bottom of a rucksack and carried as a matter of course when out in the hills. The easiest way to carry radio along might be a VHF/UHF hand-held radio. However, in hilly country, while VHF may be suitable from the hilltops, it is unlikely to be very successful from valleys. No, for maximum fun it has to be HF. But there are lots of choices to make.
The lower HF bands have the great benefit of offering good inter UK propagation but the need to carry the aerial along made me dismiss 160m and 80m on weight grounds. I finally settled on 40m as the best band for my first few outings. Both 30m and 20m seemed like good options as well but one of the fun things about adventure radio for me is sharing my adventure with someone else and to do that within the UK, 40m was ideal.
The QRP epithet can be very off putting to many. Indeed, I would not describe myself as a QRP operator. My own ideal is to use as little or as much power is necessary to achieve my objectives. With adventure radio, the weight and size limitations mean that the transmitter power needs to be quite low no heavy batteries allowed. I calculate that 9 size AA Lithium Metal Hydride batteries with 1500mAH capacity would allow about 10 hours operation with a 2.5-Watt output TX and not be too heavy to carry. Ten hours of operations would be adequate for keeping a sked on a week-long backpacking trip or for some more serious radio activity in the hills for a weekend. AAA cells would be lighter but would give less life; they are also less readily available in many places making replacement difficult.
I am writing a separate article on batteries. It is here.
The choice is either CW or SSB. I have adopted CW as my mode of operation. It is just so much more effective than SSB due to the lower bandwidth and much better use of the transmitter power to convey the information. CW has another advantage in the countryside, as when using headphones the station is completely silent in operation.
I was fortunate in having a suitable home-brew transceiver for 40 CW already in the shack. It is small and light and with an output of 1 Watt. I modified it to make it more suitable for my needs by building in a keyer (TiCK2) and also by installing the battery pack inside the case. I figured that the less separate parts that there were to the station, the more convenient it would be. All I needed to operate now was a miniature key, and earpiece and an aerial.
Figure 1 A "Trail Friendly Radio" - note that the main controls are on the upper surface for easy operation when the radio is in the ground or on a knee.
There are very few commercial radios that are suitable for Adventure Radio. MFJ has some simple SSB and CW transceivers in its catalogue but the mini transceivers from Yaesu and Icom are far too big and heavy for adventure radio [this is about to change as Yaesu have just (September 2000) announced a baclpacking radio, the FT - 817]. There are a number of kits that could be suitable. Having searched for equipment on the Internet, I have found that the USA seems to be the best source. In the USA, the concept of Trail Friendly Radio (TFR) is well developed with several excellent kits available. Wilderness Radio's SST line looks a good candidate, as do the DSW and SW lines from Small Wonder Labs. There are several others about but the best way is to build your own TFR from scratch. That way it will do what you want it to do and will only have the frills that YOU want. You don't have to design it from scratch though - few home constructors do this. You just need a few good books with the basic building blocks and away you go. The ARRL Handbook and the RSGB Handbooks are good sources. Solid State Design for the Radio Amateur (also ARRL) is a must. Building a radio from a schematic is a thrilling adventure in itself. The Adventure Radio Society is currently promoting construction from schematics - great idea.
After much thought I decided that a dipole with about 10 12m of co-ax was the most flexible aerial. It has the advantage of not needing an aerial tuner/SWR indicator, which would add extra bulk and weight. A dipole can be supported from the ends or the centre (as an inverted Vee) giving quite a lot of options. The penalty is the bulk and weight of the feeder. For 20m and below, RG174 is my choice for feeder. It is flexible, thin and light and the losses are acceptable. My 40m aerial weighs in at about 12oz.
I also carry a ball of string to tie up the ends of the dipole. I elevate the ends or centre by throwing any handy stone (with the string attached) over a bush, branch or anything else that is nearby. Winding up the aerial for transport is a bit of and art. If you simply bundle it up, it will get tangled (I guarantee it!). I use a piece of thick cardboard to wind each leg of the dipole and the feeder on. Each is wound separately making it very quick to lay out and erect the aerial. I also carry three light tent pegs for pegging out the ends of the aerial and the centre support string. As an alternative to string, I have tried 40lb monofilament. This is very light but can be hard to work with. It is also rather difficult to see which is not always an advantage! If you are travelling to an area that may not have many suitable stones, try a 2oz fishing weight (sinker); its a handy alternative.
So there it was, the complete station, consisting of the radio, earpiece, key, three tent pegs, aerial and a ball of string (to tie the aerial up).
The first tests were done in the garden. On a lovely sunny day, I cut the dipole to length and put out a CQ call. It was easy to get contacts across the UK and into the nearer parts of Europe, even with 1 W so things looked promising. I was able to practise setting the station up and got to the stage where setting up takes about 10 minutes.
For the next phase, I packed the station in the bottom of a small day-sack and drove to the island of Anglesey. I found a secluded picnic spot in a wood and set up the dipole at about 25 feet by throwing a line over a tree. A couple of calls and I was in QSO. Before long, others found my "secluded" spot in the woods and I was the subject of some curious looks. However, I was engrossed in some very pleasant CW chats. I had forgotten the thrill of making solid QSOs with a few transistors and ICs soldered together and thrown into a little box.
After a while I decided to wander off to the beach in search of a seaside location. I found a place where some woods came down to the shore. I threw a line over the bough of a tree and had several QSOs. The location was idyllic, it was warm and sunny the concept was reality!
The real test was to come however. I had planned a mountain biking trip to the Isle of Man and the Adventure Radio set-up was to come along. Before setting off, I contacted an old friend, Pat G3IOR, and told him that I would be on 40m CW over the weekend. No sked time or frequency was arranged; it was simply left to chance. I packed the radio into my day-sack before heading off for the airport. It went through the X-ray machine without causing any problems and I was on my way. I made my way to the hotel in Douglas and spent a pleasant evening there. In the morning the sun was shining. I packed a few additional things into my day-sack for the day and set off to hire a bicycle. I was soon on my way across the island in brilliant sunshine. Being in no great rush, I stopped a few times on the way from Douglas to Peel to put up the aerial and sat in the shade under trees and had some contacts. I had several pleasant and relaxed QSOs including some with people who had worked me on my Anglesey trial. The day was hot and the cycling arduous at times. Several sections of my route were off-road with very rough going but the radio didnt fall apart. On the way back to Douglas, I operated from another woodland site and was surprised by some locals out for an afternoon stroll, one of whom turned out to be licenced! No contact with Pat on the first day though. I returned to Douglas across the hills, hot and rather browner than when I set off. Radio had been the secondary objective and it had certainly enhanced a great day out.
On the second day Snaefell beckoned. Its the highest point on the island and I wanted to get there. I cycled to Laxey to see the famous wheel, parked my bike and took the tram up the mountain (lazy!). On the top I admired the view while waiting for a tram back down. This was where the adventure radio concept really came into its own. Because the station was so small and light, I took it up Snaefell. I hadnt intended using it there but while waiting from the return tram I wondered what success I might get with a CQ call. I quickly strung the dipole up as an inverted Vee from the top of a fence surrounding a communications tower on the summit. It was only about 8 feet up at the centre with the ends pegged out near the ground. I got some rather odd looks from the other trippers but I was getting used to that. No one ever asks whats going on! On the second CQ, I was delighted to be called by Pat G3IOR. We had an excellent CW chat that was the high point of my trip in all respects! Pat was my one and only contact from the summit of Snaefell. A few more QSOs followed on the way back to Douglas, some from a lovely cliff-top overlooking the Irish Sea with the aerial supported by a hawthorn tree.
It is easy to look back many years with rose tinted glasses. At the outset I was perhaps a little sceptical that my Adventure Radio concept would actually work out. In fact it exceeded my expectations. While this article has concentrated on the radio aspects, on my trips radio was very much a complimentary activity. The size, weight and convenience of the equipment means that it was not inconvenient to have the radio along with me at all times. And that in turn meant that unexpected opportunities could be seized upon.
I have assembled another station for complimentary radio activities. This one is for vacation radio. The whole station including aerials and absolutely everything fits into a slim brief case. Its first outing was earlier this year when I used it to make over 1000 QSOs from Rhodes as SV5/G3CWI without disrupting our family holiday! Complimentary radio in action again.
I am now putting together a station based on the Small Wonder Labs DSW-20 for backpacking trips this summer. My first tests with this station in the field have been successful. I have a camping trip to the Isle of Man organised for August 2000 and the DSW-20 will be coming along too. I am also planning a trip to the Rhinns of Kells mountain range in Galloway, Scotland a perfect opportunity for some 40m activity. Should be fun
Post Script - My trip to the Rhinns of Kells was a very successful walking trip but rather less successful from the radio point-of-view. The only viable place to camp next to Loch Dungeon, did not have any suitable objects to support the aerial. On the first night, I did have one QSO with the centre of the aerial just draped across the tent. On the second night we found some old petrified trees near to the shore and got the aerial up to about 8 feet off the ground in the centre and 2 feet off the ground at the ends. It was enough to make contact with my old friend Pat G3IOR in Norfolk though! We left the tree and end supports propped up in place. I wonder what archaeologists will make of them in years to come?
Conditions were appalling for the Isle of Man trip. Not only did it pour with rain the whole time but also HF conditions were very disturbed. I got up the 20 metre aerial and found a wooden hut to set up the station inside. but could only hear one station at any strength on 20 metres and he was on the Chagos Archipelago (some 8000 miles away). No QSOs resulted.
These trips may sound like failures - but the advantage of this highly portable method of operation is that it is not a burden, even when things don't quite work out as expected. The trips themselves were a success - it was only the radio that wasn't!
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