This is an article that I wrote for the RSGB regarding how I went HF Mobile - with ease. Published August 2004 RadCom
By Tim Seed, A45WG/M

REVIEW

The High Sierra 1800/Pro - If you want the ultimate in HF mobile performanceyou will need a big antenna. The High Sierra 800/Pro may be just the thing.

The basic antenna,without the 6ft whip attached. A close-up of the HighSierra universal mounting bracket.The control box and cable.I am lucky in that I live in the Middle East, in a country, Oman, that allows and encourages ham radio. At home I have a modest base station set-up, but often at the weekends (Thursday and Friday here in the Middle East) we head out into the desert for camping, exploring and socialising with friends. In summer, these trips head to the mountains as the weather is too hot at sea level (50ºC).As we often visit remote places, and are always in a very hostile climate, I had taken to packing a small HF emergency radio kit.

Despite much fun, it never really gave me the confidence that, if we needed it for real, we would be able to contact anyone. So the idea of a bigger, better, more trustworthy mobile installation was born. We drive a five-year old Land Rover Discovery Turbo Diesel - so how difficult can it be to go mobile? The answer, surprisingly, was very easy indeed.

WHICH ANTENNA?

There are two antenna routes you can take for HF mobiling: a set of monoband antennas that you stop and switch, or a single antenna that you can tune to work on any band. As we often spend four to five hours in the Land Rover just getting to a location, the thought of extra delays just so that I could see if anything was happening on 20m did not sound like a plan. So for us it had to be a tuneable antenna. I was also able to save some money and space by not requiring an ATU in the vehicle.

After several weeks of searching, head scratching, reading, considering building my own and costing we went for the High Sierra 1800/Pro. One of the main factors were the reviews from other hams on eHam.Net and the RSGB recommendations for mobile operations, which I found very helpful for a starting point [see ‘Further reading’ - Ed]. A very short time expired between ordering the antenna and a large box over 6ft long arriving. The process of reading the antenna installation manual began. After two or three reads I went outside and had a good look at the vehicle - then came back in and re-read the manual again. With the basic components out of the well-packed delivery material I thought, “wow… how are we going to fit that!”, or words to the effect. Let me make this very clear: the 1800/Pro is a large antenna. It weighs 2.5kg, and requires some substantial mounting to be secure and safe. It consists of a 4ft tuning / lower section that can be used without the second item, a 6ft steel whip. A control box with a simple rocker switch allows you to tune the antenna from inside the vehicle. Fully assembled the antenna ranges from between 10 and 14ft tall, so take care with those multi-storey car parks.

The initial shock of seeing how large this antenna was subsequently quietened by the absolutely excellent instruction manual. The images of the fitting to previous vehicles could be clearer, but as they are nearly all large US pickups, ‘RVs’, truck cabs and a tractor, alas I did not get too many ideas. The 4ft lower section mates into a very neat and well designed supplied fixing plate, the construction of which allows you quickly to install and remove the antenna when you require. The Pro pack also included the coax cable, PL259s, a mounting plate, as well as the antenna control box. The only thing you have to do is somehow attach the mounting plate to your vehicle.

MOUNTING

My goal was not to drill anything, install roof bars, or do anything that would ultimately damage the resale value of the vehicle. Magnetic mounts for a smaller antenna may be the easiest solution, but an antenna of this size requires firmly bolting on.The second requirement was that the antenna had to be in a safe place, somewhere where it did not interfere with the driver’s view of the road (so not on the bull-bars), and did not require taking apart when parking the car (we have a car shade, a sort of a Middle Eastern version of a garage, a little over 2.0m high. When installed the antenna is now below the height of the Discovery).

Just as I had formulated a plan, we were joined by Rodger Baines, A4/G3YBO, who was on a visit to Oman. Rodger was soon co-opted on to the antenna installing committee, and off we sped to get some welding and construction done. Rodger may be well known to many readers as he works for W&S in Matlock, but I’m sorry to say that site visits are not included in the HS1800/Pro package!

The following day Roger and I picked up a sturdy steel bracket that had been made by two fine gentlemen from Bangladesh. Trying to describe in Arabic what we needed was certainly difficult, but the boys did us proud. Taking off the spare wheel on the rear of the car, two long threaded bolts that had been welded to a flat stout bar were passed through the unused wheel nut holes and the spare wheel then replaced. Next the spare was re-attached as normal and on to these slightly protruding bolts a bracket was now firmly mounted. The High Sierra plate fitted snuggly to this bracket. This method of hanging an antenna will work for any 4WD with a spare wheel on the rear door, or you could fit the antenna to a tow hitch with some ingenuity and planning.

I did break the no drilling holes rule just once and drilled one very small hole in the spare wheel holder so I could firmly attach the supplied earthing cable. You cannot see the hole with the spare tyre on and I could not see any other way around this. Good grounding seems to be the key for HF mobiling.

ON THE AIR

So it was with some trepidation that the family assembled as we powered it all up. The radio hissed, and tuned, but the antenna alas refused to budge. I soon traced the problem to a connector that had a break in it. I made up a replacement part from some Bosch cable connectors, and we now had life. Later that day I wrote to the manufacturers, to explain my problem and was amazed: they replied, were helpful and replacement parts were immediately dispatched! Way to go, High Sierra - full marks for customer service! Reduce RF power, tune the antenna, RF power up, and call CQ. Straight away I received a call from the Ukraine. Having used the antenna for several weeks now, I am still impressed. We have already clocked up 500km of off-roading, and given everything a really good shake and rattle, and nothing has dropped off. Even now the antenna looks in new condition. I’ve not, however, been able to test its waterproofing and am going to have to leave that part of the test to the UK boys!

For driving around town, we usually use only the lower 4ft section. Noise levels are generally high here in town, so we only work ‘loud’ stations: RA, YB and VU. However, the antenna does work very well even without the extension on it, with Hawaii (Mobiloe to Mobile !!) being the furthest contact so far (12,000km, the same distance as working Argentina from the UK). When we travel out of the city and into the desert we always put on the extra 6ft steel whip. There is a marked improvement in your received reports, as you would expect. At all times the antenna tunes well. A warning light in the control box comes on when you have reached the maximum or minimum travel of the lower section. I generally tune only once for the 20, 15 and 10m bands, especially if I am moving, although on the lower bands you have to tune as you change frequency within the band. This is only to be expected with such a short antenna compared with the wavelength of the band in use. I have placed eight small blobs of Tip-Ex on the rear glass on the vehicle, which helps me visually align the antenna before I start tuning. This has massively reduced the time and effort required to re-tune. I actually use two vertical indexes, one with the whip attached, and the other without.

One of the unexpected advantages of HF mobile is that my normal radio working times have been altered. Most of us are only able to operate at certain times, and possibly on certain bands. This ultimately stops yielding new countries. However, by being able to operate outside the normal ‘window’, I am now ticking places off I never even hear at my home station.

In late January, we were parked out in the desert and operating on 20m.I had a nice pile-up of VK,YB and even ZL-yes, even mobile you can run pileups! I managed to bag two new countries. What was more astounding was that most people did not believe they were working a mobile station, with 59 reports coming in. I was even logged on the DX Cluster.

Operating whilst driving at up to 120KPH we often work Thailand (59), 4X4 (59) and the UK (RS 45). Now how can you complain at that? My wife writes the log for me, while our daughter in the back shouts things like “take the VK, she sounds funny” - and the whole family is occupied. One spin-off from having the mobile installation is that many people have asked me “what is it?” I do not think one of them has not been impressed when I have said “let me show you” and we have called up someone for them. They have all gone away thinking good things about amateur radio, so maybe you too can be a smaller form of GB4FUN! The best thing is that my wife thinks it is really cool and now wants to take her own licence. Had I known HF mobile would have been this easy, I would have done it ages ago.

The antenna is available in the UK from Waters & Stanton plc, tel: 01702 206835, for £379.95. Two versions are available: grey or black. The High Sierra universal mounting bracket costs £59.95. An HS-160 160m adapter is available as an option for £89.95 -Ed.] ?

FURTHER READING
The Amateur Radio Mobile Handbook by Peter Dodd, G3LDO.
RSGB. Available from the RSGB Shop.

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