broomstick vs whip

Far as I know broomstick v whip may not be the right question - antennas are designed to suit the wavelength and system in use etc......I think broomsticks are commonly CDMA phone.......whips are usually HF.......UHF models built by the pro's such as GME Electrophone all seem modular with the phasing coils mid wire and the grounding bits at the base. For mine, to choose a pro model to suit the conditions intended is the way. 6 db for mobile in flat country, 9db for static use and a shorty for undulating country (sand hills) - modulars allow you to make changes as you go..............whatever.....this approach has worked for me.I need red sand under me.

tdcockers,
I've got both and I interchange them depending on what I'm doing, I do find the broomstick antenna margianlly better all round when on a long trip on long stretches of open country, apart from that I couldn't honestly say I notice a huge difference, I though it was to do with the amount of antenna you have above the roof line of the vehicle and the distance between other antennas that made more of a difference, I have one antenna on the back (HF) and one on the bullbar (UHF) and everything works fine (ish). Keep the shiny side up

Lot's of people run UHF in road cars, nothing to be embarresed about. If you are just going to be around town there is an absolute ripper arial from GME. It's a 2.5db Dipole that you can mount to the gutters (for extra height) it's only about 30-40cm long total length. It's ground independant and $27 Retail inc GST from any 4wd shop or CB store. You'll find around the city the lower the dB the better off you are (if you are trying to access repeaters). Repeaters are normally placed as high as they can get them with very high dB arials. This means they can go the distance however unless your signal can go up in the air to the same kind of height that they are transmitting from you will not get good coverage.
Think of UHF as a bit of play-dough. You start off with a sphere or ball and the higher your dB the longer your signal gets but it get's narrow and more directional. ie If you go behind a building or in a dip you get nothing. The idea is to try and get your signal and the signal of the repeater or the person you are talking to, to overlap. Seeings as the guys setting the repeater up have already spend $$$ on high gain arials and prime positions to transmit from, all you have to do is get an arial that will reach up high enough to overlap theirs (a low db arial).
PHEW! I hope all that made sense?!?!
Basically you will very rarley be high enough while driving your car to make good use of a high gain arial while in the city. (especially Perth as it is very hilly).

A Dipole is just a different way of transmitting/receiving. Basically from my limited understanding you split the antenna in half I think UHF wavelength is approx 70cm so instead of having a half wave or quater wave antenna etc you can have a full wave but with only half the size. (there is a lot more to it than that, but someone will have to help me on that). I remeber my dad and I building a dipole out of a film cannister and 10m of Coax for my 27mhz CB when I was younger. To bit's of 5m coax joined and then fed back to the rig.
I have that little GME on a bonnet mount on my Surf and it works better than my 6db Whip and 4.5db Aliminium Dipole I had on my old 4by. Same radio too, just a ol' GME TX3000. Works fantastic though.

It depends on how good the repeater is. If you have clear line of sight I imagne you'd be ok. I can only just hit my "home" repeater from work in the car but it is 27kms as the crow flies and about 50m lower!! If you are the same height you will probally be ok.

One thing with a solid ariel, they break the bases if you drive under trees, carports, or carparks.. Ive done 2.. mate did his white fiberglass one last night in our carport, it was only a week old :(

Don't be too concerned, just get a big flexible mother so you have plently of signal capture. You'll only notice the 3db difference when operating at the extreme limit of distance. It doesn't matter if you open the repeater at strength 5 or 6 you'll be heard just the same. BEAM ME UP SCOTTY


Hooroo
Ray

I've got both a 5 foot long broomstick and a shorter ground-plane-independant whip antennas side by side on my bullbar. They are connected to a DickSmith 3-way switch. I honestly cannot notice any difference between the 2 of them under most circumstances. I "think" the broom stick gets better range in flat open country. In reality however, it's difficult to say for sure....let's face it, you're normally only going to be talking to somebody else in your own convoy/group, which usually won't be spread out more than 5 klicks or so. Any further than that, I wouldn't rely on the UHF, but would use the HF.
Cheers,
Roachie

For everything you ever wanted to know about antennas try

http://www.arrl.org/tis/info/whyantradiates.html

or

http://www.arrl.org/tis/info/antheory.html#why

Roachie hit on a very important point with the mention of ground plane and ground plane independent. With a ground plane independent aerial, you can mount it anywhere on the car without compromising signal transmission and reception. If you have a ground plane dependent aerial (as most of the older models were), they work best when mounted in the most central position with regard to the amount of metal surrounding them. This made the best place to put them the centre of the roof for most wagons! Not always very practical.

I run a 6db GME groundplane independent aerial (white broomstick) that is capable of picking up the maleney repeater from Chermside in Brisbane's northern suburbs, so that will give you an idea of performance at the Sunshine coast. They have a spring base so flex out of the way nicely. You can also interchange the aerial on the base to swap between heights and gains.

Cheers
Craig