db Rating on UHF Antenna

If by configurable you mean you have a two part antenna where you physically change a long section (9Db)for a short section (4Db) in my experience you will find a dramatic difference between the two antennas.
In brief - the 'long' section gives brilliant coverage in 'open' country but it bloody useless in 'hilly' terrain.

I don't see why people have to keep changing antennas all the time when the terrain changes?

There are so many variables that come into play when receiving and transmitting, we don't live in the ideal world.

Get a good quality 6dB antenna and leave it alone.

But then people will buy the cheapest 1-2 watt UHF handhelds and tell you they work wonderfully and they don't have a need for a better one.

Then when it comes to antenna gain people think differantly.

I think people become to anal about it.

But then again it's no different to what I do, I take 6 different types of tyres (yes thats right 30 tyres in total) when going away so I can constantly keep changing them when the road road conditions change!....so I suppose it is no different to some one wanting to change antennas all the time to suit the terrain.

Yep - I too reckon that the + - 6db area as a compromise for most conditions is a good idea - it is true that the high number radiation patterns work much like a very wide flat pancake with line of sight being very important. The low numbers work more like a ball, with better local penetration into obstacles. Another factor that was important learning for me was that rigid antennas are better - the flexible whip unit I had once (GME - with 3 wires and black / blue phasing coils) flopped around that much that the signal would (of course) sometimes be directed way up in the air (and the people we were trying to comm with insisted on staying on the ground :-o).

Thanks Guys

My GME AE409L "configurable antenna" kept snapping witht he corrugations.

I have been using the same AE409L antenna for the past 12 years. I have always used it as the 6db antenna and find that it gets out and receives well.

Prior to that I had a 9db fibreglass whip mounted on the bullbar. It was roughly 2.4m long, I just forget who made it, but I bought it new in 1985. It worked really well in the open downs country around Longreach and Winton, with mobile to base comms on simplex still possible around 100Km (no repeaters around then). The base antenna was a 12db gain that came in 3 sections that had to be glued together before we put it up on the aerial mast.
The UHF radios were (mine still is) Sawtron 999 units.

HTH