On 12/24/2010 08:02 PM, Nick Smith wrote: > I tried with a 330 ohm and 33 ohm resistor, and the voltage stayed the same > as without. I have no doubt that it is mostly power line and the 1kW AM > station that is within walking distance. :) > > Also, the ground here isn't a very good ground, so that probably throws > measurements off. > > > As for where it's situated, it's an indoor antenna. In a very noisy house. > I long for a better location. :) > > > --- Nick > > >> From: Mark J. Blair <n...@nf6x.net> >> Subject: Re: [Discuss-gnuradio] Maximum antenna input voltage on LFRX >> To: "discuss-gnuradio" <discuss-gnuradio@gnu.org> >> Date: Friday, December 24, 2010, 7:20 PM >> >> A multimeter has very high input impedance. If you attach a >> 50 ohm resistor(*) between the antenna and ground to >> simulate the input impedance of a radio receiver, then you >> should no longer see a measurable voltage with a >> multimeter. >> >> Also, a multimeter won't properly measure RF voltage. >> You're probably just seeing 60 Hz power line noise, unless >> you're very close to a high-powered transmitter. If there's >> a 100kW broadcast transmitter next door, then all bets are >> off. :) >> >> >> >> (*) or any other value you can get your hands on between >> around 25 and 500 ohms >> > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > So, you measured above 1V with a 33ohm resistor across the multimeter?
I'm glad I don't live in that house! Yikes! -- Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
