Over the past twenty years,  I have operated from a VW Campervan during the all-day microwave contests. This has the advantage of lots of storage room for equipment,  a  table-and-seat operating position and the satisfaction of remaining  out of the wind and rain  during bad weather. The idea of standing outside all day, by tripod mounted gear has never appealed to me, even though I am quite used to Scottish mountain winters! In February this year I acquired a new vehicle, a VW Transporter, 1.9L diesel. It was a “bare” panel van when I received it from the dealer but I have since floored  and carpeted it as well as lining the interior walls with fibreglass wool, plywood and carpet. Side windows were then fitted in the sliding door and the wall opposite. No rear seats have been installed as this vehicle is for microwaves only! A small operating bench is bolted to the wall beneath the window. I fitted three VW roof bars to the vehicle and added two further longitudinal, square-section bars down from the front to the rear roof bars, thus forming a very rigid frame (see figure 1 below).
Figure 1 A metal plate, 19cm x 10cm, was then fitted  midway along each longitudinal bar and drilled to take U-bolts for a 3 metre long, 50mm diameter, aluminium pipe that runs under the frame from one side of the vehicle to the other. This forms a horizontal support for a 7 metre, 2 section mast that holds the 8 element 2m beam for talkback. No guys are needed as the mast as it has 3mm thick walls and is approximately 50mm diameter. I cut it into two sections and use a joining sleeve for full height. If conditions are extremely windy I can always use just one section but things have not yet come to that!

Photo 1

The mast in the foreground  supports the 144MHz beam. A Kee Klamp holds a turning handle at a suitable height. The 1.2m microwave dish antenna is not fixed to this mast as it is on a separate mast fixed to the ladder, seen in the background. The vertical 144MHz mast hinges on its support boom by means of a further
Kee Klamp, a 90 degree joiner used in scaffolding and  barrier structures. The base of the VHF mast slots over an axle stand (I have two in my garage … they are rarely used for car servicing!) to allow for easy rotation. The mast is locked into position by tightening the hexagonal bolt in the Kee Clamp.
The microwave antenna  mast is supported at the end of a short, 4 metre long ladder  section which is clamped to the van roof  bars. Here standard ladder clamps are employed. These allow a quick but secure attachment of the ladder to the roof bars. Around 1 metre of ladder projects beyond the back of the vehicle and a 3 metre high mast, consisting of 5mm wall aluminium, 48mm o.d., is attached to the side of the ladder, near the end rung. For this I use a caravan or trailer jockey wheel clamp, obtainable at low cost at any caravan spares supplier. The clamp is bolted to the outside of the ladder so that the ladder can still be used for climbing if need be.
PHOTO 3 .... shows the clamp in close-up. Note the sturdy locking handle and general rugged construction. The jockey wheel clamp allows both a secure support for the 3 metre mast and a convenient means of locking the mast in position when dish headings have been set.


The mast stands in a further Kee Klamp fitting which is mounted on a wooden board upon which a 360 degree compass scale was carefully drawn and protected with clear varnish. The  board is anchored to the ground by means of tent pegs pushed through holes in each corner (see Photo 4). A simple direction pointer was made from a strip of aluminium , painted black and clamped to the pole as shown

The 1.2m dish has a mounting ring and this is used to attach it to the top of the support mast such that the dish can rotate through a full 360 degree arc, above the van roof. The 10GHz transverter is carried on a small platform attached to the mast, just below and behind the dish. A short length of WG16 flexiguide transfers the RF to a  “Chaparral” type feedhorn that came with the dish.  Once the mast and dish are elevated into position and clamped to the ladder, the transverter is placed on its platform and secured with a couple of “bungies”.  A 3-way spirit level (local D.I.Y again!) is then strapped to the mast and everything is trued up.

With 5 watts of RF output, a 1.2m dish and a HEMT receiver front-end, I now find that I can work 400km or more on 10GHz with relative ease, if conditions are anything like normal. I have the distinct impression that the dish performs better at the new height of approximately 3 metres above ground. Plans are now afoot to use the same dish on 5.7GHz with my newly constructed DB6NT 6cm transverter.

With a “bombproof” antenna support system and a roomy vehicle, I can now confidently face anything the British weather throws at me (says he,  with fingers crossed!). I hope readers might find some of this information of use and that we might see more dedicated portable microwave operators out and about in the various activity days and contests.