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Uhf Aerial


Duncs

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Hi all,

ordered an Icom IC-440 today and need to buy an aerial to go with it.

I've got a ute with an aluminium tray so I've read enough to decide I'll get a ground independent and mount it on the tray bar just behind the cab roof.

So I'm after some recommendations:

- do I go for a 4.5db or have a 3db and a 6db (or 9db?) and switch them around depending on where I am?

- what brand?

- anything else you think I need to think about?

Thanks!

Duncs.

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GME mate. I have a little 3dB (60cm) and a 9dB (about 1.2m) for long road trips.

When swapping between them I really notice the extra range of the taller one. But the little one is fine for daily use. It is good enough for a range of about 5km. The bigger one is good for nearly 15km.

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Depends on the countryside if its really hilly normal choice is the 3 db if its flat then the 9 db is the usual choice; you can fit both and fit an aerial selector switch - I haven't seen one in a long time though

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Thanks fellas.

I ditched the GME aerial that came with the unit after a few years.It was a 4db,but I think the aerial was either not fitted to the cable to well,or the cable was not as good internally as it should have been.It was ok for some things,but I would sometimes lose contact with the group I was travelling with over a small hill.I decided to upgrade to a RFI aerial,and chose the CD5000.This has been an excellent choice.I have no problems with communication,and last weekend on the Wonnangatta trip,had communication with all vehicles spread over a 15km range.

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i was in perth last weekend and whilst stopped at the lights at joondalup dve & wanneroo rd i was listening to a truckie raving on about a woman he just drove past who was reading a novel while driving along nicholson rd...

according to google maps thats a good 50ks away.. even as the crow flies thats a bloody long way.. i wonder if my gme couldve transmitted that far back

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i was in perth last weekend and whilst stopped at the lights at joondalup dve & wanneroo rd i was listening to a truckie raving on about a woman he just drove past who was reading a novel while driving along nicholson rd...

according to google maps thats a good 50ks away.. even as the crow flies thats a bloody long way.. i wonder if my gme couldve transmitted that far back

What you had on that day is called DUCTING. I'm a ham radio operator and have made many contacts like this.

Not uncommon and I myself have spoken to a fellow ham in New Zealand a few years ago on a handheld 2meter radio. This ducting can be caused by many things. Mostly though its the warm weather that cuses it. Think of the air as if it has 3 layers. Sometimes the inner layer gets warmed up and the outer 2 stay cooler. Radio signals travel throught the warmer layer and eventually come back to earth,this distance can be short or long depending on how long the ducting is. Antennas are a whole new ball game and what most people forget is that it might work better in some cases that in others. A GOOD earth to the vehicle is a must! You can check the earth connection out using a multimeter and should have less than 0.7ohms for a good earth. More that that and it will work but not that well. And to answer you last bit yes a good chance he may have heard you had you pushed the PTT.

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HOSS - what he heard (assuming on the UHF) is more likely the signal amplified by a repeater...

Duncs - RFI CD900 is the best IMO. Could also look at their other Antenna's; CD5000

In my experience there has been very little to no gain buy using a smaller 'gain' antenna in the high country. The terrain is just to varied and steep. If a quality 5-6db unit wont work, 99% of the time neither would the 1.5-3db's but as soon as things start to open up, the little ones are useless.

If you are looking to do extended open road / outback trips then for sure, get a bigger antenna 9db etc. but again most of the time a quality 5-6 (6.5 on the CD900) will get the job done and generally speaking hold up to the corrugations much better then the larger ones.

Another thing to think about is its no good being able to reach someone else if they cannot reach you back, another reason for just sticking with the 'standard' 5-6db antenna.

Congrats on the ICOM, bloody nice choice.

Travis.

PS - i believe sometime not so long ago GME changed manufacturers for the antennas. IIRC the original manufacturer was ZCG?

Edited to add ((lol - sorry didnt notice the original post date Duncs! So... what did you go with in the end?))

Edited by travis22
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