Ah yes, Mr. Wizard would be proud. The garage turned into 'experiment central' again, this time to see what kind of AM/FM antenna seems to work best on a motorcycle.
It isn't exactly on the scale of Consumer Reports but here's the method I used scientific and controlled or not.
The bike was parked in my garage about 25 miles outside of downtown San Diego. Each of the antennas was placed roughly where it would actually be on the bike if it was really installed (as the powered unit was). Notice in the photo (left) the Tune Trapper was mounted right in front of the powered antenna. The whip was clamped to the front brake lever. Each antenna was plugged directly into the radio, no extensions no switches were used.
Each antenna was tested multiple times with the radio set to FM and on auto seek. The AM band wasn't tested because there are just too many stations in the area with Los Angeles and San Diego stations all being pulled in by all three antennas. For AM they all pass with flying colors in this area anyway.
For the test I manually pushed the "seek" button (as opposed to "scan" which is automatic) counting the number of FM stations the antenna locked onto.
A powered unit purchased from Pep Boys (also available from Crutchfield) for about $19. It is easily hidden inside a fairing and can be powered by the same source as your radio so it is switched on/off with the key or any switch (other than the one built into the radio) you use to power the radio on/off. The antenna is 14.5 inches long.
A passive antenna by "Tune Trapper" purchased from ECShylites for $29. This antenna is flexible and is 24 inches long with the antenna cable coming out of the center so it's very easy to mount and hide inside a fairing. I don't know if it had any effect on the sensitivity of this unit but the tips of the antenna overlap the speaker magnets a bit (see photo) especially when the fairing front is installed and the tips of the antenna are pushed down toward the magnets.
A plain old aftermarket clip on auto antenna I had laying around. The antenna was extended to 32 inches and was clipped to the front brake lever of the bike for the test.
As mentioned above each of the antennas was connected to the same radio and then the tuner was set to auto seek. I was in the drivers seat for each test. I counted the number of channels each of the antennas locked onto, discarding junk signals (curiously the powered antenna kept catching two of these which I've been told may be created by the powered unit itself). A battery charger (Battery Tender) was attached just to make sure any drain on the battery from the radio wouldn't affect the output.
After four seek tests for each antenna I set the radio to a distant Los Angeles station that was too weak to be automatically locked onto by any of the three and recorded the signal and variance (fuzz in/out of sound) as I walked around the bike. The station is at 101.1, roughly in the middle of the dial. Clicking the waveform images below you can hear the reception of each of the antennas. Remember this was a distant weak signal you'd normally never listen to because the sound is a bit fuzzy with all the antennas tested.
|Antenna||Number of stations locked||Distant Sensitivity|
|Whip||25 Consistently||Very Good with a variance in one spot when I walked around the bike|
|Powered||21-23 (varied from test to test)||Good with no variance when I walked around the bike|
|Tune Trapper||19-20 (varied from test to test)||Fair to Good with a huge variance depending on where I was standing. Best reception with this antenna was with the front of the fairing mounted, me standing in front of the bike with my hands on the fairing. Speaker magnets (see photo above) may have had some effect on the effectiveness of this antenna.|
If you want to mount a radio and don't have a fairing your choice is going to be a whip antenna. The reception will be superior and besides, they look kind of cool.
If you have a fairing and you want to hide the antenna I would recommend the powered one shown (they may not all be created equal). This antenna locked onto almost as many stations as the whip and wasn't affected in the least by my walking around the bike. To me this means it would also be least affected when surrounded by other bikes/people.
For the price and all the good reviews I read about the Tune Trapper on several Harley lists I was disappointed. I expected (actually wanted) this antenna to be better than all the others and I would have replaced the powered unit in a snap if it had. Unfortunately it turned out to be the least sensitive of the three and was disappointed in the "walk around" test fading in and out depending on where I was standing and only seeming to be as strong as the others when I stood right in front of the bike (an uncomfortable riding position ya think?) with my hands resting on the fairing. I'll use this antenna in place of my current 'piece of wire' garage antenna but not on the bike.