"Michael Coslo" wrote in message
...
John Smith wrote:
On 8/27/2010 9:10 AM, Michael Coslo wrote:
Afternoon everyone,

I'm rebuilding my Bugcatcher antenna. It works well, but the XYL had a
bit of an accident last year when we had a big snowstorm, the leaves
weighted down the limbs, and the antenna, which was strapped down, still
managed to introduce itself to a limb.

Anyhow, the original antenna was mounted using 1 inch thick plexiglass,
with holes drilled to run the mast through, and tapped screw holes to
mount to the back up plate, in turn mounted to the spare tire holder.

I'm trying to make something a little prettier now that I'm rebuilding
it.

But the thing is, I'm curious about the material. Is there any
particular material to avoid? I know Plexi works, but what about PVC?
Delrin? Bondo? 8^) Miiling, water absorption, etc?

- 73 de Mike N3LI -



I have grown fond of nylon/teflon material, problem is, these materials
are difficult to find locally, and are expensive when found. In a pinch,
those plastic kitchen cutting boards are pressed into service here. The
are an opaque material, kind of "translucent white", softer than
plexiglass but hold up well under stress, will bend or warp rather than
break, seem to resist UV well enough, seem to exhibit good insulation
qualities up to VHF at least (highest freqs I have used them at.) They
can be cheaply had at used stores. They are usually 1/2 thick. Perhaps
two sheets bonded or fastened together with brass/SS hardware?

Locally findable is good. I may pick up some and try some machining
experiments. Nylon is certainly tough. Thanks, John.

- - Mike -

Mike,
I use Delrin exclusively, great machining capabilities, and excellent RF
properties, very strong with excellent wear qualities, but make sure you use
the white product ONLY. If unsure, test it in the microwave on full power
for a minute along with a cup of water, and see whether it warms.

I have used it on all antennas from HF to UHF with no problems.
Use only 316 stainless steel hardware as well, less grief later on!
73
John VK2KC