What is the most effective external antenna to put on a radio in a geographical area with poor radio reception

Answer 1

You could put up a straight vertical antenna on a pole or the tallest part of your home, but remember it will also act as a lightening rod and will need excellent grounding. A vertical antenna may not actually improve your signal either. A better idea might be a horizontal TV antenna for FM or simply a wire for AM.

The bandwidth for TV and radio are very close, in fact part of the lower end of the FM bandwidth is shared with TV broadcast channels. So any anttenna that is good for TV is also good for radio. Doesn't have to be expensive, I've stuck my multi-rod horizontal-designed TV attenna in the attic and it works fine.

You'll notice for AM reception, that as an accessory most manufactuers will provide a simple wire to run. Running this wire horizontally will gain the best signal, it does not have to be very high. Most radio signals are actually picked up better from a horizontal antenna or wire. Your location for a poor signal may just need more horizontal gain for a better signal, it is not a requirement for line of sight of the broadcast antenna for a good signal.

Now if you want the very best reception, take a look at the picture in the link below:

Answer 2

If you need better AM reception, you'll want a long wire (LW) antenna. It is literally a long wire, 100 feet or longer in a straight line, suspended off the ground. It doesn't need to be high (only 3 ft or so), and the radio station(s) you want to hear should be perpendicular to the wire.

Of course, it can still be hit by lightning, so you still need to be cautious about that.

You might consider a box loop or ferrite rod antenna, too, for interior use. They can rotate null strong stations or enhance weak ones.

Short wave reception would require a similar antenna, but shortened (i.e. tuned) to the proper length for the band that you want to listen to.