GME vs ZCG Scalar

Neither, ( and do you mean AE4705?)

Get a 6.5db whip from either of those or RFI and put it on the roof if you are really serious about decent performance. The ones you state are too heavy for that. Preferably put it in the middle of the roof, but anywhere up there will be a lot better than on the bull bar.

Stick ( or any) antennas on the bullbar are more show than go. The bullbar is a stupid place to mount an antenna. It simply will not perform well. If you have tinted windows it is even worse as they act as a shield.

Height is might. Bar mounted antennas are a bull bar company initiated design, not a Radio company design.

Both antenna brands have been around for years and are both good quality, GME don't make their own antennas whereby Scaler do..... Scaler is an antenna company that sells other gear and GME is a radio company that sell other gear.

The GME antennas would be made by one of the other antenna manufactures like Scaler and rebranded GME.

You will get a good run out of both and performance would be top notch...... however I would prefer GME as there antennas are more readily available and supported by more retailers Australia wide.

As for the 2.1m 8.1 dbi gain antenna..... you know they are only sold in pairs and they are not real antennas...... but the look so cool!...... you also get a 40% discount if used on a ute with an extremely large bull bar.....

Seriously the advantage over gain is often over exaggerated in a mobile situation as the terrain often changes, the downfall of that antenna would be the length limiting access to many places and the increased chance of damage plus if you had to remove it trying to fit something 2.1m into a vehicle is not the easiest thing.

The other two would be a better choice for practicality, reliability and would out perform the bigger antenna in most applications.

Thats a question that cant be answered simply. Antannae choice is all about the terrain, your need and your expectations.....by way of explanation

The lower the gain the greater the chance of signal in hilly/undulating terrain
The higher the gain the greater distance signal will travel and be sent/received but the terrain needs to be much flatter.

A low gain antannae radiates in a ball pattern. A high gain antannae radiates more like a football shape.......Look at this link ..easier to understand

http://www.zcg.com.au/antenna-gain-explained.html
Google will find others as well

My standard antannae is the GME 4705 with 4.5db....a very good all rounder. Mounting position also affects performance...bullbar mount can at times be sheilded by the vehicle body in a straight line if you are trying to talk to a vehicle strainght benhind you...get a few bends or corners in the road and all ok

Roof mount is the best but their survival rate off road is not the best!

cheers

As described by bungarra in the previous post, a higher gain antenna has the effect of "focussing" the outgoing signal. In simple terms, instead of sending some signal straight up (towards the sky), some stright down (towards the ground) and some at every angle in between, a higher gain antenna focusses the signal more tightly around "horizontal".

If you imagine a ball of clay skewered on the antenna as being "low gain", you will notice that no matter what angle you tilt the antenna the signal will still reach a receiver that is within the diameter of that ball. For a high gain antenna, imagine the ball is flattened to a disc (like a dinner plate). It is the same volume of clay, has a much larger diameter than the ball, but is very thin. If the antenna is tilted backwards then the "dinner plate" also tilts, and a receiver in the same place as in the "ball" scenario may now be above or below the thin slice of signal (dinner plate) and so will not receive the signal. However when the antenna is vertical, because of its larger diameter the "dinner plate" reaches receiving antennas that are further away.

The power going from the radio to the antenna does not change, but a high gain antenna concentrates that power in a horizontal disc which therefore extends further than the spherical signal from a low gain antenna. But when the high gain antenna tilts, that narrow slice of signal tilts above or below the receiving antenna. So in flat country, or for base stations where the antenna is stationary, a high gain is great. But if the antenna is mounted on a vehicle that is constantly changing angle (side slopes, up and down hills or even two wheels in a gully), then a receiving antenna can lose the signal very easily as the "disc" of signal changes angle. This effect is worsened by the distance between the two antenna, the angle of tilt, and the degree to which the broadcasting antenna flattens the signal (i.e. the gain).

So as has been stated, in flat country a high gain antenna will perform better, but in hilly country that same high gain antenna might not let you talk to a vehicle 100m away!

This is why some companies sell antenna with a spring base and interchangeable whips - you can change whip to suit the terrain, or the car wash!

Antenna height is important, but roof mounts are exposed to damage from trees and you have to find a way to run the cable up to them! Bullbar mounted antenna are less exposed to trees, easier to mount and, if chosen on length, can give a good guide as to whether the roofrack will hit the garage roof, tree, carpark etc......

Hi Scoop,

Just to add to your confusion - I had a UHF antenna (6.5db) on a spring mount on my bull bar for a trip across the Savannah Way (i.e. corrugations) - On the trip I had two flick themself off at the base - So I tied it back for the rest of the trip so as to dampen the spring. - My current vehicle has a poly bar (smartbar) and it does not vibrate near as much on corrugated road

My Next G antenna (6.5 db) is mounted on my snorkel on a bracket I made myself - I have no trouble with it

Reading previous comments suggested taht I am on the right track with my snorkel mount - Before my next trip I might try to put my CB antenna on the roof rackbut that would be too high around town for underground carparks etc

Regards
Peter

Scoop,
Yes! you can mount a small aerial on your roof but I know I won't. Reason, hole in roof, and you have to get the coax out of the vehicle as well. Top of snorkel is feasible but again you have to get coax there without drilling any holes. Again this can be done but not for me.

Here is a photo of my work ute's dash. All the aerials were mounted on the Backboard behind the cab and once a month they would be replaced as they got wiped out.

Yes you will get further with a roof mounted aerial but at what cost. I have a bar mounted aerial and I don't have any problems getting between 18 and 20 k which I find acceptable.

Aerial wise, either of them will be fine. I like GME because I have never had any problems with their gear, be it in trucks or vehicles.

The vehicle dash shown ran on main roads, rural roads, tracks, surface mines and underground so it was used everywhere in all conditions.

Would I get a noticeable difference by mounting to antenna to the top of the backboard rather then the bull bar? If the backboard is a better spot do I go ground dependent/independent?