Mobile Antennas and Mounts

[sssman]

I have a Uniden BCT15 scanner mounted in my Toyota Rav4 with a RadioShack glass-mounted antenna. I recently discovered I am not receiving certain frequencies while my handheld scanner and Minitor pager are. After spending hours reading articles and several different forums, I have come to the conclusion that the problem is my glass-mount antenna. So I am looking for a new antenna & mount. I do not want to drill holes to mount the antenna.

Therefore, I am considering either a hood lip mount or a roof rack mount.
I have found several from Diamond, for example:

http://www.rfparts.com/diamond/k515snmo.html

Also Larsen:

TMB or TLP mounts: http://www.larsen-antennas.com/docfiles/ASB8/Mobile/MobileIntroduction.pdf

Also Maxrad:

T Series or MT Series
http://wildcard.pctel.com/images_product_overview/pdf_docs/TSeries_PDS.pdf


Any recommendations? What is the difference between all these mounts? Is hood mount or roof rack mount better? I have read that you have to be careful about what cable you use and not to use the stock cable. Any recommendations?

I also need to buy a multiband antenna, preferably black. Do not need 800Mhz functionality. Mostly VHF (150Mhz) and UHF (460Mhz), some VHF-Low (30Mhz). Any recommendations? I have read that Larsen and Maxrad are the best...

Thank you.

 

[jonny290]

Roof racks require a roof rack, that's their downside. They also don't give quite as good of an RF ground, but you aren't transmitting, so that point is debatable.

It pretty much comes down to a convenience factor. Some people like the roof rack mounts because most of them are 'fold-over' and let you run antennas high on the vehicle (good for vhf/uhf). Others like the better ground plane and more 'low profile' appearance of the trunk mount. Either mount with a good antenna will give you performance far beyond that terrible glass-mount. Trunk lip/hood mounts do have the edge as far as install cleanliness, as you can usually hide the coax the entire way. With roof rack mounts, you have to find an entry point for the coax.

Don't worry about replacing coax yet; get the new mount and antenna, and see what you think about the performance. I will caution you against mounts with RG-174 size coax (approximately 0.1" diameter) - RG-174 is terrible, terrible coax and the minor install worries it solves are never worth the cable loss. Make sure it comes with RG-58 cable or better.

Unless your number 1 listening target is low-band, I will suggest trying a 2m/440 dual band amateur antenna in the 30-50" category. I only say this because specifically getting an antenna to cover VHF-low may mean that you deal with a 6- 8 foot antenna, and many areas just do not have sufficient lowband activity to warrant a tuned antenna for it. A 5/8 wave will function as a base-loaded 1/4 wave on VHF-low and will certainly pick up stuff in your county, if not better.

edit: one final note: you can spraypaint antennas so if you find the perfect antenna and it's silver, don't balk - just buy it, install and tune it, then unscrew the antenna and hit it with a couple coats of enamel spray paint in the color of your choice. Nobody who cares about the antenna's performance will mind if you decide to sell it later. all of my antennas are urban camo'd to blend into my back yard, and I sold a vertical and the guy actually appreciated the camo job.