Rectification of the signal can cause small DC currents as you suggest. Any non linear behavior that treats both the positive and negative RF swings equally can not result in DC generation but instead causes harmonic generation of the RF carrier. Do you consider salt water as capable of behaving differently to the positive versus negative instantaneous RF voltage and current waveforms? Where is a reference to this behavior?
The high frequency RF signal itself can not penetrate the water to any significant degree due to reflections from the surface. Also, keep in mind that radar signals are aimed to keep their energy toward targets that are above the water surface in general, especially close by. And the beam widths are so narrow that only a small portion of the radiated RF impacts the water near the antenna. Dave -----Original Message----- From: Hoyt A. Stearns Jr. <[email protected]> To: vortex-l <[email protected]> Sent: Tue, Jul 7, 2015 5:50 pm Subject: RE: [Vo]:Possible cause for coral reefs dying... Any non-linearity in a medium like salt water will cause baseband currents. From: David Roberson [mailto:[email protected]] Sent: Tuesday, July 7, 2015 2:45 PM To: [email protected] Subject: Re: [Vo]:Possible cause for coral reefs dying... You are kidding right? Any signal that shows up is merely being translated in frequency from its original location down to the baseband. The only signal received is very close in frequency to the carrier wave. The modulation signal at the low Hertz rate is visible at the receiver output, but it was not radiated by the transmitter. Dave -----Original Message----- From: ChemE Stewart <[email protected]> To: vortex-l <[email protected]> Sent: Tue, Jul 7, 2015 2:22 pm Subject: Re: [Vo]:Possible cause for coral reefs dying... David, Of course the low frequency square pulses show up on receivers, that is how pulsed doppler works! http://www.rfcafe.com/references/articles/images/Signal-Analysis-Modern-Radar-R-S-6.jpg When it is on (every pulse) a weather radar puts out ~1,000,000 WATTS, (32 billion watts EIRP) Stewart On Tue, Jul 7, 2015 at 2:10 PM, David Roberson <[email protected]> wrote: Come on now Stewart. If you take the time to analyze the spectrum of a pulsed radar signal, you will find that all of the energy is contained in a location surrounding the carrier frequency. Also, how well do you think a dish radar antenna being feed by a bandwidth limited waveguide is going to radiate those 200 to 1000 Hz signals? If you can show me where any significant amount of that low frequency is radiated I will assume that you are knowledgeable in RF design. It is easy to convince people that know nothing about radio and radar systems to be concerned about unimportant issues. And, as everyone knows, statistics can prove just about anything that you wish to prove based upon the restrictions that are placed upon the data that is analyzed. The same type of reasoning is used to keep kids from being vaccinated or cellular antenna locations from being located in the ideal places. We need real science instead of variable statistics to settle these issues properly. Dave -----Original Message----- From: ChemE Stewart <[email protected]> To: vortex-l <[email protected]> Sent: Tue, Jul 7, 2015 1:53 pm Subject: Re: [Vo]:Possible cause for coral reefs dying... Dave, the pulse train is a square wave, with the "on" amplitude approx 900' long or longer depending upon duty cycle, bouncing between clouds/planes and the suface of the ocean Just one weather radar has an EIRP of 32 billion watts of power, which gets ducted and scattered by planes and the atmosphere, more during storms. Mildly shocking biology with every pulse, depending upon impedence Electricity can kill you in a nanosecond, each radar pulse is 1000 times longer that that in duration. Admit it, you sparkies screwed up :) Stewart On Tuesday, July 7, 2015, David Roberson < [email protected]> wrote: The radar pulse rate does not effect the penetration into the water. In other words, the 200 to 1000 Hz rate is applied to the carrier and does not independently appear anywhere else. Dave -----Original Message----- From: ChemE Stewart < [email protected]> To: vortex-l < [email protected]> Sent: Tue, Jul 7, 2015 8:12 am Subject: Re: [Vo]:Possible cause for coral reefs dying... VLF radio waves (3–30 kHz) can penetrate seawater to a depth of approximately 20 meters. Hence a submarine at shallow depth can use these frequencies. Most of the radars pulse at 200-1000 Hz. Most of the coral disease is in shallow water <20 meters On Tuesday, July 7, 2015, ChemE Stewart < [email protected]> wrote: Except low pulsed frequencies On Tuesday, July 7, 2015, James Bowery < [email protected]> wrote: On Tue, Jul 7, 2015 at 1:42 AM, MarkI-ZeroPoint <[email protected]> wrote: This is primarily meant for fellow Vort, ChemEng (Stewart), but some others may have an interest… Stewart, I think I may have a cause for your hypothesis re: a link between our modern radar systems and the dying of coral reefs… ... Time to break out the tin-foil hats??? No need. Salt water shields against EM penetration. This email is free from viruses and malware because avast! Antivirus protection is active.
