At 5/4/2008 07:44, you wrote: >Paint a polythene cup with your favourite antenna covering. Let it dry and >put it into the microwave oven along with a cup of water (to act as a >dummy load) >Cook for 1 min on max power. >If it gets even slightly warm its no good for antennas. > >er.. can I please have an award for the first cooking recipe to get past >the moderator on repeater-builder > >Ian >G8PWE
This is an excellent suggestion. I have 2 sets of ceramic plates in the cupboard: plates from one set get so hot in the microwave I think they get hotter than the food on them, the others stay at room temperature. It's possible that some materials may still have low loss @ 50 or 146 MHz, but have high loss at 2.45 GHz (where the microwave oven's magnetron tube operates), so you may get some "false positives" with this test, but if it passes it's definitely a good material. Bob NO6B
