Monitors who are consistently successful in monitoring the HF spectrum will tell you that their success is the result of their antenna systems just as much as the receiving equipment they use. The old adage “the more metal, the more signal” is the best formula for success. Those living in an apartment or condo know that not being able to put up an outdoor antenna can be a real hindrance to monitoring the HF radio spectrum.
The only real solution to this problem is to use one of the active HF antennas in the market. And while these antennas do perform well, they have their own set of problems that they bring to the listening equation.
First, noise loves antennas that are vertically polarized. If you want to see exactly how much noise you really have in your neighborhood, switch your HF antenna over from horizontal to vertical polarization. The differences can be startling.
Second, to make up for the smaller capture area of most active antennas versus a full size longwire or dipole, the active antenna uses an amplifier (the "active" portion of an active antenna). That amplifier not only amplifies stations you want to hear, but amplifies any noise at the same rate. If noise was an issue at your location with a vertical, it will be an amplified issue with an active antenna.
There is no easy answer to the noise problem, but the AOR WL-500 Window Loop goes a long way towards reducing some of the noise issues we have seen with other active antennas in the marketplace.
During our test of the WL-500 we used it on a several receiver models, including the venerable Sony 2010 portable. My local shack RF environment tends to get a bit noisy at times with computer and television interference being the primary culprits. And while noise was still an issue using the WL-500, having the ability to turn and null out some of that noise was a definite plus. Compare that to some of the other active antennas on the market that only use an omnidirectional vertical whip antenna, and you realize that the WL-500 might be just the ticket for monitors who can’t put up outdoor antennas.
We took the WL-500 out of my shack environment and hiked into the woods with the 2010. Our noise issues disappeared and really let the WL-500 shine. The 16dB amplifier really helped pull out some nice DX on the 2010. The portability of this antenna will be especially appealing to the camper and traveler alike. Assembly was a snap and took about a minute and a half to accomplish.
The loop is constructed of flexible twin cable braced by a center pole which splits into two sections so that it can be easily stored away. When set up, the loop forms a diamond shape with an approximate diameter of 23.6 inches (60cm). The loops covers 3.5 to 30 MHz with a range switch mounted at the termination point of the loop (switching at 10 MHz).
A length of screened cable is supplied, which is terminated to a RCA Phono plug to connect the loop to the control box. The control unit provides preselection and amplification terminated in a BNC socket for connection to the receiver. The unit exhibits good, strong signal handling characteristics.
The WL-500 can be powered using an internal 9VDC battery (battery consumption is around 16 mA) or an external 12VDC power source (not included) using the 1.3mm power socket.
While the WL-500 will operate below 3.5 MHz, performance in the medium and longwave portions of the bands will be enhanced if used with the optional 500LM bar element.
If you are looking for an excellent travel or camping shortwave antenna and space/weight is a consideration, then the AOR WL-500 should be on your short list of antennas you should consider for the task. The WL-500 sells for $198.95 plus shipping and is available from Grove Enterprises http://www.grove-ent.com (ANT24).
The Grove Catalog and Buyer's Guide