In my recent post, The truth about portable amplified shortwave antennas, I argue that small, portable amplified antennas are, by and large, ineffective. The post comments are interesting, however; many readers agree, and some tout the Sony ANT-LP1 as worthy, but Mike made the following comment about his amplified antenna:
The one active antenna that I have been pleased with is one I built myself. The design was by ON2NLT and uses a ferrite rod, so it is somewhat directional. Rotating the unit (it is very compact) often allows nulling out noise or interference. You have to be careful not to crank up the gain too much though, or you will amplify the noise floor. The link is here
Looks like a fairly simple project. Thanks, Mike!