I would like to replace the horsewhip antenna on my Jetta with a VG sharkfin antenna. I’ve heard that reception with sharkfins may not be as good as with the stock antenna. Does anyone have any experience with or information about sharkfin antennas?
This is for an FM radio? I’m guessing it’s going to be a powered “active” circuit, rather than just a piece of wire. I have no idea how the performance compares. Cell phones and OnStar (which uses cell phone services) are much higher frequency (shorter wavelength) than FM… even so, they still may be powered antennas.
If you’re just looking to get rid of the damage-prone buggy whip antenna, have you looked to see if there are any windshield mount antennas? Some cars come with fine wires built into the windshield glass – maybe a stick-on version is available (for inside the car). If they can do it with rear-window defrosters, I’d think they could do it with an antenna. Before buying one, check to make sure there aren’t any state laws against sticking something on the windshield.
A shorter, wider antenna is going to have a broader bandwidth, but much lower gain. It will have to be amplified, but unfortunately when you add an amp to an antenna, you not only boost the signal, you also boost all the noise it picks up. A 31" whip is about the best vertical mounted antenna that you can get for FM.
Windshield/rear window antennas are horizontally polarized and so match the polarization of the transmitter. They usually work better as long as the ground plane of the roof doesn’t get in the way. They are also more directional so turning a corner could cause you to loose the signal. Tape on antenna’s are available, or were at one time, I had one but eventually switched to the whip. The OEM windshield/rear window antenna’s seem to work better than the tape on ones anyway.