I'm looking for a stronger antenna for a 2006 Silverado, and my mechanic wants to put a factory antenna in it, but I'm looking for an amped antenna in it. What should I be looking for if I want to pick up better signals from further away? Is a CB antenna better for a radio antenna?
I currently have a break off at the "screw on" antenna. I'm not going the XM route.
While if you used a CB antenna, it might work ... it wouldn't work very well. If you look at an OEM antenna for your truck, you'll see it has not only the central core (sort of like a CB antenna), it also has a separate wire wrapped around this core. You can see it in this image:
Without this secondary wrapping, the whip portion won't work near as well as stock. My suggestion is to follow your mechanics recommendations.
A Citizen's Band radio operates in the range around 27 MHz on the RF spectrum. Sirius/XM™ satellite radio is substantially higher on the chart, approximately 2330-2345 MHz. This is important because the wavelength of CB radio is much longer than that of Sirius/XM™ satellite radio, requiring a longer antenna for optimum reception. Ordinary FM radio in the USA ranges from 88 MHz to 108 MHz, which has lower wavelengths than CB and higher than Sirius/XM™ radio.
Each of these frequencies will have a different length antenna to work properly.
In the image above from Paulster2, the wire wrapped around the antenna is a vortex shedding device. Without it, the antenna will shake, vibrate and generally destroy itself, especially when it gets wet (personal experience.)
Antennae that have a spiral coil at the base indicates that the antenna has been designed and tuned to provide for frequencies that would otherwise require a much taller/longer antenna shaft: photo from above linked site.
The best antenna for reception is an antenna cut for the desired frequencies. A half wavelength antenna is ideal. For automotive purpose a quarter wavelength is used. The car body acts as the other quarter wavelength. The reception pattern of the antenna is generally in the area of most metal. For example If the antenna is mounted on the roof the signal is received more from front to rear and less from side to side. The length of antenna should be 29.5 inches mounted vertically. For AM band reception on a car radio isn't an issue because of internal trimming capacitors to compensate for the shortness of antenna.
The wavelength on the FM band is about 3 meters, AM band in North America vary between 560 meters to 176 meters in length.
For a CB antenna to work it would have to be seriously modified. You can take a mag mount antenna and remove the base loading coil winding and put a jumper wire across were the loading coil was. Then from the base measure from there to the tip of the steel whip and cut at 29.5 inches from the base. Cut the coaxial cable to the length you need providing the length is an odd multiple of 29.5 inches. Attach connector. Plug in . ROCK ON... :)
A lot of times longer is not nessesarily better sometimes actually worse.
