You don't care if the cup of water heats up - you are looking to see if the painted cup heats up. The water is only there to prevent burning out the microwave.
Joe M. Burt Lang wrote: > Fine except for one problem. Water is an excellant absorber of the > microwaves used in the microwave ovens (2.45 GHz) So your water will > heat up quickly irregardless of the coating. The only substances that > are better absorbers of that frequency are animal or vegetable fats > because they contain 9 times the molecular bonds (the O-H bond) that > actually do the absorbing. > > Burt VE2BMQ (who used to be a professional chemist) > > IM Ashford 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 >> >> >> ----- Original Message ----- >> *From:* skipp025 <mailto:[EMAIL PROTECTED]> >> *To:* [email protected] >> <mailto:[email protected]> >> *Sent:* Sunday, May 04, 2008 2:44 PM >> *Subject:* [Repeater-Builder] Re: antenna question - Dip It and >> Scotch Kote >> >> I constructed a 6 meter beam some years back, worked like a bomb >> even at 25ft above ground elevation. To ensure my pride and joy >> would last a long time I sprayed it with clear Krylon brand spray >> paint. >> >> The antenna was instantly unusable regardless of my efforts to >> remove the paint, re-tune or otherwise modify the antenna. I later >> learned that type of paint contained materials with a horible >> D-Factor. I was never able to use the antenna again, although it >> remains in my back yard as a reminder. >> >> cheers, >> s. >> >> > "Chuck Kelsey" <[EMAIL PROTECTED]> wrote: >> > Boy, you took a gamble. I'd have been afraid that this action >> > could have either messed up the VSWR or shifted the resonant >> > point of the antenna. Then again, maybe it did and either >> > you don't know that or it wasn't significant. >> > >> > Chuck >> > WB2EDV >> > >> > >> > ----- Original Message ----- >> > From: "skipp025" <[EMAIL PROTECTED]> >> > To: <[email protected] >> <mailto:Repeater-Builder%40yahoogroups.com>> >> > Sent: Sunday, May 04, 2008 12:19 AM >> > Subject: [Repeater-Builder] Re: antenna question - Dip It and Scotch >> Kote >> > >> > >> > > Hi Robert, >> > > >> > > You might get lucky... because they might also have advertised >> > > the dip-it as an insulator material, which means someone was >> > > hopefully looking at the dissipation factor (aka D-Factor) when >> > > the compound was engineered. Time will tell... >> > > >> > > cheers, >> > > skipp >> > > >> > >> "georgiaskywarn" <kd4ydc@> wrote: >> > >> Someone else told me that after I had put a whole can of dip >> > >> it on the db408 I showed you. I went back and covered every >> > >> inch of it with liquid electrical tape. I have had good >> > >> results in the GA sun with it. >> > >> 73, >> > >> Robert >> > >> KD4YDC >> > >> >> > >> >> > > ------------------------------------ > > > > Yahoo! Groups Links > > > > >
