unsure of best aerial

[dm0011]

hi , can anyone tell me what they think is the best bull bar mounted aerial for a uhf , i live in the Adelaide Hills so therefore lots of ups and downs, cuts a lot of stuff out for a line of site aerial.

[Red Baron]

GME make a base that fits both the large fibreglass antenna for outback use or a smaller stainless whip for around town or in the scrub. RF Industries also make a good product, so check them out too. They make a ground independent base with a good spring on it that has a fibreglass lower that tapers up to a steel whip. I got my radio from Prestige Comm's in WA, and their website has plenty of info on different antennas; might be worth a look....Cheers Chris.

[DirtyDawg]

I Have a GME4706 antenna and found it to be the most useful all rounder and built for 4wd so it can take a knock

[JDNSW]

hi , can anyone tell me what they think is the best bull bar mounted aerial for a uhf , i live in the Adelaide Hills so therefore lots of ups and downs, cuts a lot of stuff out for a line of site aerial.

UHF will be line of sight regardless of what antenna you use - arguably a high gain antenna will be less use in the hills than in flat country where the extra effective radiated power is some use. Also note that a high gain antenna gets the increase in gain by having a more directional (flatter) radiation pattern, which is more likely to be aimed in the wrong direction in hills where the other station is at a different level or the vehicle is not level.

John

[waynep]

Yes a "ground independent" antenna base with a 1/4 wave ( non gain ) or longer "gained" whip on top is essential if you are going to mount it on the bullbar.
The standard 1/4 wave antenna ( at UHF this is a stainless steel whip about 6" long ) needs a "ground plane" to work properly, which is ideally a flat sheet of metal 1 sq metre or so under the whip. This used to be provided by the vehicle roof when they were mounted on the centre of it. In a ground indepedent, or "elevated feed" antenna, as you see on most 4WDs, you effectively are going to a 1/2 wave dipole design ( sort of ) that doesn't need a ground plane.

The bullbar isn't the ideal location for any antenna because it is low down, has poor signal to the rear, and is susceptible to electrical noise from the engine bay, but as the BB manufacerer's provide a noice little bracket for an antenna, it's convenient I guess ( mine is not on the bullbar )

[njz]

I've got a GME AE4018K1 on my bar. I've used it a fair bit in the hills and have found it to be a great all rounder. Its 4.5dB and just short of a meter tall.
GME have some useful info about radiating patterns and antenna gain in their catalogue.

http://www.gme.net.au/land/PDFs/ant_broc.pdf

[Michael2]

It's been said - but in laymans terms -

shorter aerials for hillier or wooded terrain,

taller aerials for flat terrain.

So even with 'short' hills like Simpson Desert sand dunes, the shorter aerial would be better for getting the signal over the dune.

Use the springy ground independent bases (the short aluminium pole).

I used a 3.5dB gain aerial on a ground independant base on the bullbar of the SIII.

On the Defender, the previous owner had the aerial routed to the roof (rack) so I use a small flexible 'rubber' aerial. A mate who works for Uniden recommended it and said they install them on tractors that always scrape shed doors and they don't break or fail.

[GrahamH]

I've had good advice and service from:

• Radio Specialists
• 243 Seacombe Rd South Brighton 5048
• (08) 8298 3906

They're on the web at http://www.radiospecialists.com.au/
and they have a good range of antenna's.

PM me if you'd like to have a look at my vehicle's antenna array (I'm in the Blackwood area).

[dm0011]

Thanks for that Graham I might well do that because I think it is neccesary to also get a radio aerial to get some better reception on the normal radio stations

[Slunnie]

It's been said - but in laymans terms -

shorter aerials for hillier or wooded terrain,

taller aerials for flat terrain.

Its actually the gain of the aerial that makes the difference in relation to the radiation pattern rather than the length. The interesting thing is that my GME AE409L which can be setup as a 9db is about as long as my GME AE4705 4.5db aerial.

From my experiences, if you get mixed up in the bush where things need to be durable, and the terrain is up and down then the AE4705 is excellent as the gain is about 4.5db and the construction is fibreglass on a heavy spring and bar mount - sensational aerial. In the plains such as central Aus, Cape etc the bigger AE4706 is excellent at about 6db and it radiates straight over the roof of the car. I can Rx/Tx with other vehicles using this aerial that others inbetween us cant! For a wire aerial I've found the GME AE409L to be excellent when setup as a 6db.