Many black plastics are "blackened" by the addition of "carbon black" that can make them rather lossy at RF! "Been there, done that" in my work - at 900 MHz. 73, Charlie, K4OTV Delrin is a trademark
Yep, that's the "black pigment commonly used" that I refer to. It's used in the PE jacks of coax too! I can't say I've tested black - vs - white materials in the microwave region, but I've never seen
Non-UV-rated clear 0.118" Polycarbonate is visibly yellowed and mildly brittle after 5 years in my outdoors environment in the sunshine and other weather. I think this is the plasticizers "drying out
I don't want to belabor this, because I think Greg was going to try Delrin, but Delrin homopolymer is slightly different than other acetal resin copolymers. They are similar, but not exactly the same
All good points. We have used gray UV-stabilized poly carbonate to mold covers for electricity watt-hour meters that had some rather stringent requirements fr with standing ambient sunlight. The prob
On Mon, 16 Dec 2013 14:32:41 -0500 "Charlie Cunningham" <charlie-cunningham@nc.rr.com> wrote: Many black plastics are "blackened" by the addition of "carbon black" that can make them rather lossy at
On Mon, 16 Dec 2013 14:32:41 -0500 "Charlie Cunningham" <charlie-cunningham@nc.rr.com> wrote: Many black plastics are "blackened" by the addition of "carbon black" that can make them rather lossy at
I have been using 3" black Derlin (Acetal)insulators at the base of my 160 m vertical. Because the antenna is only 91 foot tall, there are substantial voltages on the insulators at legal limit. Indee
Using grommets to create additional leakage/creepage distance is clever! I never would have thought of that! Best is to turn the material on a lathe, but in a pinch you can use a bolt as a mandrel in
Using grommets to create additional leakage/creepage distance is clever! I never would have thought of that! I'm cheap and lazy, not clever. _________________ Topband Reflector Archives - http://www.