Re: [Discuss-gnuradio] Maximum antenna input voltage on LFRX

[Nick Smith]

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 <address@hidden>
> Subject: Re: [Discuss-gnuradio] Maximum antenna input voltage on LFRX
> To: "discuss-gnuradio" <address@hidden>
> 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