ve3pzr said:
The PCR100 does well in AM mode on the shortwave bands. There are many AM commercial broadcasters all over the world. The best (cheap) method is to use a long bit of wire. If you can get a long chunk of wire outside you will be amazed at what you can hear. The longer the better is the basic rule for shortwave. I went to the local hardware store and bought a small spool of wire. Some satellite TV coax is low loss and works well for receivers. Use the coax to get to the outside and then attach the wire to the center wire.
For signals above 30 mhz, a Discone is a not-bad general purpose antenna. Search the net for some pictures.
Hardly necessary; the antennas wiki here at RR has numerous HF designs, as well as some discones and other commercial built antennas. In general, the ScanTenna, Diamond D130J discone and the NilJon all have a good following, but there are many others, too.
One note; I know this is true of the PCR1000, and I would guess that the PCR100 has this as well; on HF, watch the length of the antenna, as overloading is a common probem. This tends to be somewhat specific to your area of the world, as the East Coast of North America tends to get blasted somewhat harder with the high power HF broadcasters than the West Coast or Midwest. Some folks have put a small tuner or passive preselector (like the ones MFJ sells) as a solution.
For some situations, longer is not necessarily better. 73s Mike