Re: [Discuss-gnuradio] What antenna for WWV/WWVB?

[michael taylor]

On 12/7/06, Heiko Jones <address@hidden> wrote:
> What is the minimum antenna(s) I would need to pull in WWV (5/10/15Mhz)
> and WWVB at 60KHz with my USRP with the Basic RX daughtercard? I was
> wanting to look at decoding the BCD time code.
>
> How about if I wanted to get my local airports ATIS at 126Mhz?

Short answer: It depends.

Slightly longer version: It depends upon three main factors 1) RF
frequency 2) distance from source (signal lost based on distance), and
3) atmosphere conditions ("propagation") which is frequency dependent.

WWVB at 60KHz would normally use a loop antenna around a ferrite core,
similar to those found an AM radio. Depending on where you are (cont
US vs. Europe) a small AM loop antenna might work, or a large outside
antenna might be needed if you are in EU.

A VHF signal like 126MHz is roughly line of sight plus 5% (I think), a
1/4-wave vertical would normally work if mounted outside above a large
percentage of nearby buildings and terrain. So a 42cm (~16.5 in)
vertical antenna with a metal ground plane mounted at roof height
would likely work if you are "near" an airport.

A useful starting point is the ARRL's Technical Information Service web pages,
<http://www.arrl.org/tis/tismenu.html>. A copy of the ARRL Handbook
can also be an accessible reference for many common RF related
questions written in an accessible form (compared to standard EE / RF
engineering references), so if you plan on doing a fair bit of SDR
work I would recommend getting a recent copy.

-Michael Taylor, VE3TIX