UHF Aerial

[Walky88 Member Find all posts View Profile Close Walky88]

Just wondering what UHF Aerial everyone is running???

I head out west occasionally when the wife lets me to go hunting and would like a good one.

I don't want one that is 2m tall however would like good range.

was looking at

http://www.oricom.com.au/oricom-uhf-...e-antenna.html (0.4m high) or

http://www.oricom.com.au/oricom-uhf-...es/anu300.html (1.0m hight)

I'm not sure what dbi means but the first one is 2 and the second one is 4.5

this is one 6.5dBi and 0.8m high

http://www.oricom.com.au/oricom-uhf-...es/anu200.html

Any ideas?

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

You need to way up your terrain and how far you want to reach. I find this picture pretty self explanatory. ..


There is a bit more to consider also but thus is the premise for dbi

[Walky88 Member Find all posts View Profile Close Walky88]

From talking to a mate the higher the dBi the longer you can hear in a straight line however the lower the dBi is better for hill terrain.

While you are online RanJ i have a question for you.... How did you get your wiring from your spotlights on your roof to inside the vehicle??

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

That pretty m uch sums it up mate. Also look at durability. A flexible whip will hold up much better in the bush than a fibreglass solid whip. But on the highway at 100+kmh the stiff fibre glass has much less sway.

Wiring goes straight up the rain gutter on either side of the windshield. Positive runs up the passenger side and ground runs up the drivers side. I'll take some happy snaps and flick them to you tomorrow if I remember mate. Fwiw... the wiring isn't inside the car at all...its all located in the engine bay.

[Walky88 Member Find all posts View Profile Close Walky88]

That pretty m uch sums it up mate. Also look at durability. A flexible whip will hold up much better in the bush than a fibreglass solid whip. But on the highway at 100+kmh the stiff fibre glass has much less sway.

Wiring goes straight up the rain gutter on either side of the windshield. Positive runs up the passenger side and ground runs up the drivers side. I'll take some happy snaps and flick them to you tomorrow if I remember mate. Fwiw... the wiring isn't inside the car at all...its all located in the engine bay.

That would be awesome Cheers in advance!

[Guest Close Guest]

I have a little rubber ducky antenna mounted on a knockdown bracket on the awning. It gives me much better range than a higher gain antenna mounted on the bullbar. This is because the antenna is up high and doesn't have to travel through the car's body. The knockdown bracket assists with undercover car parks.

Whichever one you buy, make sure the cable length is enough for where you want to mount the antenna and the main UHF unit.

[Muzza72 Lurker Find all posts View Profile Close Muzza72]

Same as amts - I also have 3db rubber ducky mounted on knockdown bracket attached to rhino platform rack seems to work a treat I can put a larger antenna with higher db gain if need when traveling in outback.

[Walky88 Member Find all posts View Profile Close Walky88]

Hey amts or Muzza any chance of a photo???

[Guest Close Guest]

Hey amts or Muzza any chance of a photo???

http://www.pradopoint.com/showthread...ckdown-feature

[Walky88 Member Find all posts View Profile Close Walky88]

Awesome going to have to order one!

[Guest Close Guest]

I was on a trip with my bro-in-law in Newnes. I had my 3dB on my awning and he had a 4.5dB on his bullbar. At the end of the day, I was about 5 mins ahead of him and descended into the old ZigZag railway. There was a turnoff that isn't marked that went to the ZigZag railway. If you missed this you end up in Lithgow.

I radioed him to remind him about the turnoff but didn't get much of a response apart from something feint. When we got back to our place of accommodation, it turned out that he heard me loud and clear and responded but his transmission signal went straight over us as we were lower but he was still up at the plateau. So this demonstrates really well the graphic shown by RanJ.

Most of the 4WDriving is done in undulating terrain. It is only in the highway where you can gain from having a high gain antenna. But if you place your low gain antenna up high, you can get more range out of it.

[sweetpea Senior Member Find all posts View Profile Close sweetpea]

You need to way up your terrain and how far you want to reach. I find this picture pretty self explanatory. ..


There is a bit more to consider also but thus is the premise for dbi

I think this diagram is a bit misleading.

UHF frequencies as used in UHF CB are essentially a line of sight signal path.

It does not matter what gain the antennae are, the hill in between will stop the signal.

If the graphic was redrawn with the vehicles on opposite sides of a valley with the lobe pointing away from the second vehicle it would be much more convincing.

S.

[sweetpea Senior Member Find all posts View Profile Close sweetpea]

I was on a trip with my bro-in-law in Newnes. I had my 3dB on my awning and he had a 4.5dB on his bullbar. At the end of the day, I was about 5 mins ahead of him and descended into the old ZigZag railway. There was a turnoff that isn't marked that went to the ZigZag railway. If you missed this you end up in Lithgow.

I radioed him to remind him about the turnoff but didn't get much of a response apart from something feint. When we got back to our place of accommodation, it turned out that he heard me loud and clear and responded but his transmission signal went straight over us as we were lower but he was still up at the plateau. So this demonstrates really well the graphic shown by RanJ.

Most of the 4WDriving is done in undulating terrain. It is only in the highway where you can gain from having a high gain antenna. But if you place your low gain antenna up high, you can get more range out of it.

When designing a radio system it is normal to consider that the gain for an antenna is the same for transmitting and receiving. In other words, it the radios are performing the same, the signal quality will be the same in both directions.

If it is better in one direction it is likely that one of the transmitters or one of the receivers is not performing as well as the other or there is a fault in one of the antennae. It is almost certainly not a consequence of the rated gain of each antenna.

S.

edit.
Or it may be that the squelch in your radio was set a bit too high and the received signal on your radio was not high enough to open it.

[Guest Close Guest]

When designing a radio system it is normal to consider that the gain for an antenna is the same for transmitting and receiving. In other words, it the radios are performing the same, the signal quality will be the same in both directions.

If it is better in one direction it is likely that one of the transmitters or one of the receivers is not performing as well as the other or there is a fault in one of the antennae. It is almost certainly not a consequence of the rated gain of each antenna.

S.

edit.
Or it may be that the squelch in your radio was set a bit too high and the received signal on your radio was not high enough to open it.

My bro-in-law was at the top of the plateau. I was nearing the bottom. His higher gain antenna has a narrower lobe so his signal went over me.

[D4D-GXL Advanced Member Find all posts View Profile Close D4D-GXL]

3dB gain is all you need for hilly terrain. If your out on a plateau like the dessert go with a 6dB or something like that. It is that simple.