UHF antenna - which kind?
Submitted: Friday, Jul 16, 2004 at 09:46
ThreadID:
14703
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CruiserHead
I am in the morket for a new antenna. My trips take me mainly to the
Flinders Ranges and the flat country around Lake Eyre, so I am thinking 6db or 9db gain. To be mounted on the bullbar, so ground independent. I use the UHF mainly for repeater access and emergency contact, not so much for talking to other vehicles. How would a 9db function in the Flinders? What is the difference between those fat, long fiberglass rods and the thinner, shorter, often metal rods? What should I be looking for?
Thanks in advance to the experienced crowd, here!
Cruiserhead.
Reply By: Utemad - Friday, Jul 16, 2004 at 09:59
Friday, Jul 16, 2004 at 09:59
Hi,
For big open areas you can't beat the GME AE4706. Although it leans a bit at 100km/h. The benefit of this series is that they are interchangeable so long as you fit the larger spring base. Means you can fit a variety of antennas to suit the landscape.
I have the AE4706 and AE4705 as
well as my old AE409L stainless 6/9db antenna. It will still fit on the new spring base but I don't use it off road as the grub screws fall out and with the 9db attachment it bends right over at 100km/h. This series is ground independent.
I think most of the stainless antennas are lower gain ones except for the AE409L. Fibreglass rod type antennas will stay upright better at speed thus giving you better range/reception while driving. Don't hit anything with them though! They tend to bleep ter if you hit solid things like concrete car park entrances.
Choosing antenna
AE4700 series
When it comes to antennas there are heaps to choose from.
Utemad
AnswerID:
68023
Follow Up By: Member - Jeff M (WA) - Friday, Jul 16, 2004 at 15:10
Friday, Jul 16, 2004 at 15:10
The Larger fatter antennas are Dipoles which are different to your standard "peice of wire" or "whip" antenna.
Dipoles offer your a more stable signal. They are more delicate and heavier. Dipoles are very often used as base antennas. Some people who must be making up for some other kind of inadequncy use them on their bullbars, but personally for offroad use the smaller the better!
I have a dipole, but it's a miniture one only about 30 cm tall and low gain. Approx 3db.
6/9db atennas will work gret in the hills, as long as your right on the top! As soon as you get somthing in the way, it will block your signal.
If you are tryingto acces repeaters, a lower DB arial is the best option as the repeater's have very expensive high gain (generally 24db etc) on them and are situated on top of large hills or towers. They are getting the distance for you, you just need to be able to reach up with your lower db arial and grab hold of the signal. If you are "beaming" straight out ahead, you likely to miss the repeaters signal all together as it's much higher above you.
Hope it makes sense!
FollowupID:
328689
Reply By: Brew69(SA) - Friday, Jul 16, 2004 at 12:52
Friday, Jul 16, 2004 at 12:52
I use a uniden 6db metal antenna mounted on the roof rack as it gives a far better range than on the bull bar. When in the city i just swap it for a short rubber type which still does a reasonable range.
AnswerID:
68040
Reply By: CruiserHead - Friday, Jul 16, 2004 at 21:15
Friday, Jul 16, 2004 at 21:15
well, the roof rack it not an option for me, and neither is the gutter. it is also much easier to mount on the bullbar, wiring and all. so in this case, do I go for one that is long, to reach up as high as possible? in which case it would be a fibreglass rod? I think I will go with a 6db, seems like a good distance/terrain compromise.
thanks all for your help, I'll
shop around. anyone know of a good online
shop?
cheers,
cruiserhead
AnswerID:
68099
Follow Up By: Mad Dog (Victoria) - Friday, Jul 16, 2004 at 22:18
Friday, Jul 16, 2004 at 22:18
Yep, if you must mount it on the bullbar go for a bit of height, 6db ground independant elevated feed.
FollowupID:
328761
Reply By: Bob Y. - Qld - Saturday, Jul 17, 2004 at 08:15
Saturday, Jul 17, 2004 at 08:15
CH,
Can't beat the 6dB POLAR for performance, price and size. The GME 4018 should be as good, though "they" say it is only 4.5dB. Both are extended gain, and could be mounted on either bullbar, gutter mount or roof rack.
Have had the GME 4705 & 4706 mentioned above, and while the concept is very practical, the longevity of the whips is hopeless. Both whips have gone out of tune, so have a GME 409 screwed on the base at present. They don't last either, on corrugated roads, though the performance is adequate.
We use a 6dB whip on work vehicles, sold by Access Electronics in
Rockhampton. Performance is excellent, but would be too big for town use. There'd be broken flouro tubes in every servo you visited.
The UHF aerial debate can get almost as big as the Patrol/Tojo debate. Some blokes must spend half their trips swapping from 6dB to 3, and then back again.
Hooroo...
AnswerID:
68120
Reply By: The Banjo - Saturday, Jul 17, 2004 at 09:18
Saturday, Jul 17, 2004 at 09:18
I use the 6/9 db GME 409 model but it doesn't do very
well in undulating terrain. In convoy, I often miss out on comms. eMailed GME and they said I should go closer to 4.5 db setups - made a bush 4.5 db temporarily for a recent trip and it it did
well. Might leave it on !
AnswerID:
68122
Reply By: CruiserHead - Monday, Jul 19, 2004 at 14:14
Monday, Jul 19, 2004 at 14:14
thanks for all the helpful replies. I think I will
shop around for a longer, but not too long 6db for the bull bar. will let you knowhow I go.
thanks again,
cruiserhead
AnswerID:
68432
Reply By: CruiserHead - Tuesday, Jul 20, 2004 at 17:00
Tuesday, Jul 20, 2004 at 17:00
So I finally made up my mind and got a COL6MSK from Mobile One, 1760mm dipole, 6dB Ground independent Co-linear for mobile or base with MSCOL. Got a good deal at DickSmith, they tell me the line is dicontinued (probably by them), but 5 years warranty will be honoured.
see here:
http://www.mobileone.com.au/antenna/477.htm
Thanks again!
CruiserHead
AnswerID:
68677