Jerry, Do you have a pump or electric valve on that water line?
On 9/11/06, Tim Ellison <[EMAIL PROTECTED]> wrote: > I got one for you that goes to show everything does have a fundamental > resonant frequency. > > I had recently purchased an Icom AH-4 antenna coupler and was trying out > antenna configurations. I had never used a tuner or coupler before, but > I "thought" I knew what I was doing (NOT!). I decided to mount the AH-4 > under an eve on the end of the house and run a long wire out to one of > the trees in the back yard. So far, so good. Since the antenna coupler > was about 16 feet off the ground and it needed a connection to ground, I > ran a 1" ground strap to the earth and terminated it with a ground rod, > since that is what the instructions "told" me to do. Being extra smart, > I tied this ground rod to the A/C service ground as per the NEC. > > Now, remember that 16' long ground strap? Ok, now what is the length of > a wire that is 1/4 wavelength on 20 meters? About 16'. So, I crank > this puppy up with 100 watts and I am now effectively transmitting a 20 > meter signal into the ground of my house wiring. The one device that > REALLY didn't like this was my powered subwoofer for the Home Theater > that started feeding back at the EXACT resonant audio frequency of the > metal chimney connected to the fireplace insert. It REALLY starts > oscillating since I have magically "found" its fundamental resonant > frequency. It made the loudest noise; sounding like the walls were being > drummed on by some giant Org. The dogs went crazy. The XYL is running > through the house screaming, thinking that a tornado is hitting the > house. > > Now I'm at the other end of the house, the shack door closed, headphones > on making QSOs as fast as I can with Europe using my new antenna. I > can't hear a thing going on in the far end of the house. The shack door > bursts open, which does get my attention and in flies 2 dogs and a XYL > totally freaking out! Needless to say it was easy to find the root of > the problem and I decided that I needed a little more fundamental > knowledge about what a "real" RF ground is and why balanced antennas a > really good things. The fireplace was grateful too. > > > -Tim > --- > Integrated Technical Services > > "Too much of everything is just enough." > -Rob Barlow > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Mike Naruta > Sent: Monday, September 11, 2006 7:53 PM > To: Allen Boehm; FlexRadio@flex-radio.biz > Subject: Re: [Flexradio] SDR1000 WPI (Water Pipe Interference) Problem > > Yep, it was an interesting demonstration on Mythbusters. > > > Too bad Jerry changed it. I'm guessing that it would not have vibrated > with just carrier. > > > Mike - AA8K > > > Allen Boehm wrote: > > It is not an urban legend. Every thing has a resonate frequency. If > > you dig back into the history of Nikolai Tesla and his earthquake > > machine. Here are two related patents registered by Tesla: Patent No. > > 511,916 (Jan. 2, 1894) titled "Electric Generator" and Patent No. > > 514,169 (Feb. 6, 1894) titled "Reciprocating Engine". > > Al > > > > _______________________________________________ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com > > _______________________________________________ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com > -- "There is nothing more uncommon than common sense." -- Frank Lloyd Wright _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
