At the recent Hillsboro Air Show , I operated a portable station from First Aid Tent 2 out on the airfield. Although it was completely overkill, we used a Comet GP-3 mounted about ten feet up. We used a couple of sections of standard TV mast connected to a tripod (which was then zip-tied to a canopy strut). This worked extremely well and is part of Ed Clark, KC7ZBI’s standard portable setup.
More recent than the air show, I worked a shift on the Hood-To-Coast relay race. The race is mostly through back roads in the very northern bits of Oregon countryside. Cell service is spotty in most places, and completely absent in many. I was in a place where there was no cell coverage, and even the small 2-meter magmount on the car wasn’t getting into the repeater very well. This gave me the excuse I needed to assemble a ready-to-go portable setup like the one we used at the Air Show.
The GP-3 is an ideal antenna for this, but at $100, it’s definitely something you don’t want to just throw around. So, I decided to formulate a mechanism for protecting it during transit. Ed uses a fishing pole holder with tennis balls around the antenna shaft, which works pretty well. However, I had the idea of using standard PVC pipe parts to make something a little more custom. The result is pictured here:
The parts involved are:
- 1″ PVC schedule-40 pipe for the shaft (cut to length)
- A 1″ PVC cap for the tip
- A 2″ coupler
- A 1″x2″ PVC bushing on either side of the coupler
- A 1″ slide plug for the non-fixed bushing
I assembled all the pieces so that things fit snugly. The bushing on the free end of the coupler makes a nice removable cap, and the SO-259 on bottom of the antenna slides into the plug in the hole of the bushing. This means that everything fits snugly and doesn’t move around much. I think that I will add some felt tape around the opening to the 1″ PVC shaft to keep from rubbing the antenna element too much. The ground plane radials stay nicely attached to the exterior with some thick rubber bands.
All pieces are glued with PVC cement, except the end bushing that is supposed to remain free. A few more pictures are available here.