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Plastic insluator for Antenna what type? - VK6TU - 24-09-2017

I plan on making a few antennas in the future that will require a insulator to fit into some aluminium tube that will be suitable for RF.
I am wondering what would be the best type plastic to use?

Some options are
HDPE
Polyurethane
Acetal Delrin®
Teflon

Acrylic
Nylon

And possibly more in many colours.
This site shows a good range of options
http://stores.ebay.com.au/Warlond-Plastics?_trksid=p2047675.l2563

As I have a lathe I will be able to machine to the correct size but I want to make sure the insulator is suitable for RF and UV.

Thanks

Michael
VK6TU

RE: Plastic insluator for Antenna what type? - VK3LU - 24-09-2017

Hi Michael,
You can test plastics for rf compatibility by putting pieces in the microwave for a few seconds or longer.
I presume the results can be extrapolated down to vhf or hf. But I stand corrected.
Remember that nylon is hygroscopic.
I don't know about uv resistance  though. Black plastics could be an indication.

Nev

RE: Plastic insluator for Antenna what type? - VK6TU - 24-09-2017

(24-09-2017, 08:52 PM)VK3LU Wrote: Hi Michael,
You can test plastics for rf compatibility by putting pieces in the microwave for a few seconds or longer.
I presume the results can be extrapolated down to vhf or hf. But I stand corrected.
Remember that nylon is hygroscopic.
I don't know about uv resistance  though. Black plastics could be an indication.

Nev

Nev,
Thanks, Have used a microwave before to test unknown plastics, the only problem is I no longer own a Microwave and more importantly I have not got the plastic yet, prefer not to get some if its not suitable, that's why I asked

Thanks for the tip on Nylon, its off the list.

73 from Michael
VK6TU

RE: Plastic insluator for Antenna what type? - VK5ZD - 21-12-2017

Polycarbonate is another option. Reasonably strong and relatively immune to UV.

RE: Plastic insluator for Antenna what type? - VK2ZIW - 26-12-2017

to "fit inside Aluminium tube".
I'd suggest fiber-glass rod as in electric fence posts, see your local Produce Store.

Here on 6m and 2m beams, I use PVC 1/4 inch sheet cut into small squares or rectangles
screwed onto the (note square) boom and round elements with stainless screws.
Everything is at low voltage. Life in the sun, 30+ years.

Another plastic of use: Recycled plastic garden stakes.

Screws, forget Bunno's, find a real nut and bolt supplier and buy boxes of 200 8G x 3/4 for about $7 a box.

There are various grades of stainless-steel. 316 grade is much dearer than 304 and harder
to work. For antenna we only need 304.
You can, after filing, solder to the stainless screws. (proper flux though, Chemtools VIOFLUX)