I recently changed out the stock antenna on my smart for one from a company called ShortAntenna (
Stubby Antenna). This antenna is a "B" series, adjustable in length from 4" collapsed to 11" extended. With the antenna collapsed to you need a fairly strong station to get good reception, extended to 11" the signal noticeably improves for weaker stations, but even in the extended position the reception is significantly weaker than with the stock antenna. This is what I expected when I bought it, but since 95% of my driving is in a strong radio signal area, it doesn't particularly bother me.
What does bother me though, is that when the antenna is extended, it will cause a reasonably loud whistle above 20 mph, with the source being the inverted conical top piece of the antenna. When collapsed it will fit tightly against the lower section of the antenna and no whistle is noted, but when up, the cavity which is exposed in the bottom of this conical cap generates the noise. Falls easily into the "strongly irritating" category
My question is this. Has anyone else with an extendable stubby antenna noted this and found a fix? I've tried various cavity modifying experiments like putting some tiny o-rings into the cavity, but these just made it difficult to completely collapse the antenna and didn't stop the whistle anyway. I can always go back to the stock antenna and these stubby antennas are so inexpensive that it doesn't matter much (about $10), but I'd just like to make the little antenna work out.
Any suggestions would be appreciated.
Linear Mode
