Yes, for shortwave a 10-20 foot piece of wire can be used. You do not need
to spend a lot of money to get started. If noise is an issue, google
for 'shielded loop antenna'. You can also buy more expensive antennas.
Try,
http://www.universal-radio.com/catalog/sw_ant.html


Why would a shielded loop receive less noise than, say, a classic wire turn
loop?

Dale W4OP