Hi Bob,
Interesting idea. I think that the foam insulation, even though it doesn't absorb microwave energy, will alter the electrical characteristics of the helix. So, the dimensions - the diameter and/or the turn pitch - will need to be changed. It certainly would make for a durable antenna, however.
Good luck,
Greg KO6TH
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From: w7lrd@comcast.net To: AMSAT-BB@amsat.org Date: Tue, 5 Aug 2008 00:35:30 +0000 Subject: [amsat-bb] brain picking time
Hello all I have a couple of questions of some things I am working on- Has anyone used that expanding foam that you use for filling holes and gaps in walls etc. I am trying to use it for helix support inside some PVC pipe for a 2.4Ghz 6 turn helix. Once expanded it provides a rigid support for the coil. It stays cool in a microwave oven. I have no idea what if any the properties are regarding microwave applications. As with most of my efforts I just build and try.
Next question- which probably would be more aimed at a EME bb. I have a 12 foot TVRO I am building a patch feed for 1296, and feed it through 50 feet of LMR400 to my IC-1271A. I want to see if I am able to "hear" EME signals. Of course if I am able to, you can guess what my next effort will be. This will be a cheapie effort as I am only using stuff I already have. I do have a KJ6KO L band 70 watt amp. 73 Bob W7LRD Seattle
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