UHF Antenna

Submitted: Tuesday, May 13, 2008 at 18:53
ThreadID: 57576 Views:5972 Replies:3 FollowUps:3
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Has anyone had any experience with an RFI CD5000 UHF antenna on a diesel 4wd doing a lot of outback travel (with the constant vibration)?
Originally had a GME AE4702 suggested to match to a GME 3440 radio but as I would prefer to leave the antenna mounted on the bullbar this becomes a problem with anything over 900mm high when enetering and exiting the garage frequently.
Or is there some other option of installing two antenna and using the shorter one around town, then attaching the larger antenna and switching to this for the outback travel, and how would one actually perform the switch between the two antenna?

Spencer J
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Reply By: Member - Olcoolone (S.A) - Tuesday, May 13, 2008 at 19:08

Tuesday, May 13, 2008 at 19:08
I would stick to one antenna for everything, I don't understand why some people insist on changing antennas all the time.

Have a look at the GME AE409L 6/9db UHFCB Antenna, thats what we use on some of our vehicles.

I understand the theory but when you are driving are you going to get out and change the antenna when you drive through hilly terrain and then change it back when the terrain becomes flat, then the terrain becomes hilly again and you have to change it again.

Regards Richard
AnswerID: 303641

Reply By: spencerj - Wednesday, May 14, 2008 at 04:36

Wednesday, May 14, 2008 at 04:36
Ihave heard from retailers and installers that antennas such as the 409L have a tendency to snap at the coiled section. Just what I have been told.
Spencer J
AnswerID: 303690

Follow Up By: Member - Olcoolone (S.A) - Wednesday, May 14, 2008 at 07:55

Wednesday, May 14, 2008 at 07:55
We have them on 3 vehicles and never had a problem, the oldest one is about 6 years old.
FollowupID: 569834

Follow Up By: Grungle - Wednesday, May 14, 2008 at 07:59

Wednesday, May 14, 2008 at 07:59
Hi Spencer,

The coil sections are called phasing coils and it is a measured inductor used to join different wavelengths of antennas together so as to improve gain.

I forgot to mention below that we see the grub screws fall out of the phasing coils as well due to not being tight enough or vibration so it pays to check them periodically.

FollowupID: 569835

Follow Up By: Stu & "Bob" - Wednesday, May 14, 2008 at 09:33

Wednesday, May 14, 2008 at 09:33
Hi Spencer,

I have a AE409L mounted on my car which is around 15 years old.

No problems with it at all, and it has travelled over some pretty rough tracks during this time.
FollowupID: 569855

Reply By: Grungle - Wednesday, May 14, 2008 at 07:54

Wednesday, May 14, 2008 at 07:54
Hi Spencer,

The CD5000 is a great antenna that we sell quite a few of. We mainly sell them to people who want a permenantly fixed antenna to deter theives and also people that want to match it to their mobile phone antenna in the way of the CD2195.

I have seen the odd broken one that has coped a whack from a low object just above the spring where the spring cannot react quick enough so the fibreglass sheath breaks but this is pretty rare.

With the AE409L antennas, I am not really a big fan due to their whipyness. Ideally you want something that stays vertical when driving otherwise your transmission characteristics change and you get less range. The AE409L in 6db form is not too bad but in 9db form bends back quite a way when driving at 100km/hr so you you defeat the purpose of having a high gain antenna.

The other problem with the AE409L is that the stainless 1/4 wave whip at the base is prone to break so you have to buy the complete base and the 6/9db whip as seperate items. Also they are prone to theives. However saying that they are popular antennas.

The AE47XX series is a very good strong antenna that performs well (from GME) as does the RFI made CD931. I would stay away from other brands as they are just not reliable enough or fudge their performance characteristics so they can be comparable to the better brands (Axis for example have some badly tuned antennas for something that is supposed to be pre-tuned).

Regardless of what people say, you should always SWR an antenna whether it is pre-tuned or not. We have seen so many badly installed connectors and crushed cable that its not funny. However a lot of antennas nowdays have a slimline phone connector (FME-101) allready installed on the antenna cable so it can be passed through a firewall and then you have a couple of adaptors to choose from that join the cable to the radio. This takes the pain out of fitting connectors and knowing that everything is 100% spot on.


AnswerID: 303706

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