UHF Aerial
Submitted: Tuesday, Feb 08, 2011 at 21:53
ThreadID:
84218
Views:
8357
Replies:
16
FollowUps:
7
This Thread has been Archived
Mark & Jacqui
I have broken several UHF aerials recently. My aerial is mounted on the bullbar of my vehicle and it seems the vibration is breaking them. The aerials that have broken have all been stainless steel type (I prefer these as they are easy to see past). Can anyone recommend an areal that can withstand extended periods on a corrugated road?
Reply By: miandering fiander - Tuesday, Feb 08, 2011 at 22:11
Tuesday, Feb 08, 2011 at 22:11
Sounds like you may have a Prado,
I have and had the same problem with both fibreglass and stainless aerials.
If so I took the springingness out of the spring at the bottom and have not had a problem since. about 8 months now.
The spring was allowing the aerial to whip back and
forth violently and was snapping.
I got a piece of conduit heated it up until it was soft and pushed it down over the spring
AnswerID:
444711
Reply By: Member - Captain (WA) - Tuesday, Feb 08, 2011 at 22:18
Tuesday, Feb 08, 2011 at 22:18
Hi Mark,
Stainless Steel whip aerials are very prone to stress fatigue, I bet they are breaking off close to the base?
I have two black fiberglass ground plane independent aerials that has lasted me for many years, I swap between a 3ft 4.5db whip and a 6ft 7.5db fiberglass one with its own spring base. Both these aerials have seen may, many corrugations, quite a few tree whacks and still work fine. Being black, they tend to fade away in the background and you very quickly find you do not see them when driving.
Cheers
Captain
AnswerID:
444715
Reply By: Member - Graham H (QLD) - Tuesday, Feb 08, 2011 at 22:28
Tuesday, Feb 08, 2011 at 22:28
Must be a rattly diesel I have had a 1018K on the bull bar of my cruiser for nearly 3 years It has done over 60,000k on all sorts of roads and still is in one piece and still works.
The RFI cell phone aerial was a bit wobbly as the spring is not as stiff as the UHF one.
I slit a piece o slightly smaller black poly pipe and cable tied it around the spring Its been there for 25 months and is fine.
The 1018K is just the right height that if it goes under a doorway or
carpark height bar the car will go under as
well.
Smart thinking there boy.
Cheers
AnswerID:
444717
Reply By: Sand Man (SA) - Tuesday, Feb 08, 2011 at 22:42
Tuesday, Feb 08, 2011 at 22:42
I fail to understand why folk persist in mounting their antenna on the bullbar.
The bullbar is mounted to the chassis and as such has considerably higher vibration effects when compared to the vehicle body.
I have an RFI CSW series Phasemaster™ antenna, just a sinple SS black coated 900mm one mounted on the vehicle guard close to the front windscreen.
It sits a few cm's above the roofline giving excellent reception and also happens to be perfect for judging height of access to underground carparks, etc.
I do have an "antenna" bracket mounted on my bullbar, but this is used for sand flag attachment and have not had a failure with this setup.
Bill.
AnswerID:
444720
Reply By: Member - John Baas (WA) - Tuesday, Feb 08, 2011 at 23:04
Tuesday, Feb 08, 2011 at 23:04
I had exactly the same problem on my LC200 fiteed with an ECB bullbar.
Apparently the bullbar was designed for airbag compatibility and it does vibrate heaps. Even with spring bases the aerials didn't last long. They were different models but all were flexible and developed harmonic vibrations under corrugations which, while pretty to watch, totalled them tout suite.
a year ago I changed to rigid white fibreglass sticks, still on spring bases, which sit there like a
rock. I've had no problems ever since; even on the horrific corrugations on parts of the CSR last year.
Cheers.
AnswerID:
444724
Reply By: Muntoo - Wednesday, Feb 09, 2011 at 00:35
Wednesday, Feb 09, 2011 at 00:35
Damn, i just purchased a AE4810K aerial too.
And i know my bullbar moves around a bit also.
Wish i had of read threads like this earlier.
My previous aerial was a thick fibreglass, and this time around was told go for the stainless steel whip aerial as they are much better.
AnswerID:
444733
Follow Up By: Mark & Jacqui - Wednesday, Feb 09, 2011 at 22:10
Wednesday, Feb 09, 2011 at 22:10
G'day Muntoo,
Thanks for the info, I am going to steer away from the stainless steel aerials and give the fibreglass ones a go. I do however prefer the stainless aerial as I believe they work better and are more durable as I have previously damaged fibreglass aerials with branches especially the ones with the little wire that winds around the outside of the stick.
Good luck with yours.
Cheers.
FollowupID:
716978
Reply By: Tim - Wednesday, Feb 09, 2011 at 08:00
Wednesday, Feb 09, 2011 at 08:00
Unfortunatley this has very little to do with what brand of antenna you use and rather the combination of the vehicle vibration frequency and the exact material used in your antenna.
The reason is due to resonance. Anything vibrated at its resonant frequency will fall to pieces. Obvioulsy the people who have had issues with antennas breaking are vibrating at or very near the resonate frequency. Increasing the thickness of the antenna will just delay the same outcome. It is the same for other materials and structures including glass and even things like bridges.
In order to prevent this we have to alter the frequency the antenna vibrates at. I knew a cocky who had a S/S whip with the small coils roughly the middle of the antenna. He had an older model rodea which are quite "rattly". To solve the problem he put a small (8mm OD) hose through the centre of the coil and taped it in place. It was enough to alter the frequency of the vibrations and stop it vibrating at the resonate frequency and job done.
Tim
AnswerID:
444739