Years ago, I had a mobile scanner in my car, and RS was selling a pretty good all band scanner antenna. I havent seen that exact antenna at RS for many years. I guess they no longer carry it, but it worked great, so great, that I had bought myself a second one for the work van that I was driving at that time. I do not know how well the current RS mag-mount scanner antennas are made, and I have no clue how good the reception is on one of them, but I do have experience with band specific mobile mounted antennas. I currently own a retired police cruiser, and instead of leaving the plastic dummy caps on the antenna holes on the trunk and the roof, I have opted to re-install band specific antennas using the NMO style mounts. These are the original mounts that once passed thru the drilled out holes, and they support the installation of NMO style antenna bases. I have reconfigured all antennas using the NMO mounts, but I'm getting off the subject... your best bet might be to purchase a good quality, name brand antenna for your mobile application... a Motorola, Antenex, Tram, Larson, or Laird manufactured, band specific antenna, mounted on a magnetic base might bring you some results worth smiling about. They are available, in most cases, to come as mag-mounted antennas, and they are usually very good quality, and look professional. I trusted in buying some of these manufacturers antennas (w/ NMO option mounts in my case) from ebay. They even carry the Motorola 800Mhz police style antenna, which I might add brings in crystal clear reception of local 800 trunked systems. These antennas were purposly designed to work correctly, and I don't think they would let you down, unless your trying to monitor a signal that is just too far away to begin with, because that could give you poor reception right from the start. A roof mounted antenna might give you better results that a trunk mounted antenna, short distance coax is usually the rule of thumb, and good connectors all play a role in reception, while trying to minimize connector adapters. I have nothing but great results from the ebay purchases I have made, each mfr's antenna was built with quality in mind... they are usually commercial overstock or left overs from the previous years manufacture as new antenna models are invented, but they can be purchased at a great price.
