Inverted 1.2 metre dish with 10 GHz waveguide feed connected. The 5.7 GHz horn is fitted so a 3 degree elevation change brings that band into play. Having the feed at the top with the dish inverted keeps the rain out of the horn and removes any risk of hitting your head on the arm when standing on the roof rack. Bracing bars are 10 mm carbon fibre tube with quick-detach fittings epoxied into the ends. Elevation strut is a cheap 12 volt mechanical actuator.
The rotator fits on a mast section that tilts over so the dish can be worked on for band changes. It rests on a trestle or “mast scissors” when luffed over. This is the 3.4 GHz setup with a commercial C band scalar choke on a 9cm feedhorn I made for Tony
Rear view of the dish with two ODUs for 5.7 and 10 GHz
Another implementation of the rotary mast clamp. This one has a side entry for use on narrow lane verges. It also has a ground-mounted tilt plate and rotator. The fishing-rod stand allows you to lower the mast but it remains supported above ground for adjustments and band changes.
The second version of the clamp. The brass nuts fit on to captive clamps with 3/4 inch spigots to allow rapid removal of the clamp from the roof rack.
Close-up of the mast clamp with the gate open, showing the rollers and the knurled locking nut
The first prototype clamp
The 2.4 metre mesh dish on Tony’s van-mounted 60ft pneumatic mast
Elevation mechanism I made for the 2.4 metre mesh dish. The arm at the right is for the counterbalance weights
Porthole feedthrough in the mesh surface to allow shorter feeders to be used. Brass insert in the Delrin bush is for the quick-detach carbon fibre feedpoint support rods. Designed to be dismantled while standing on the van roof on a stormy winter night in pitch darkness with horizontal sleet on a Yorkshire Dales hilltop at 54 degrees North.
