NEW D-MAX /MUX /COLORADO FORUM

NEW D-MAX /MUX /COLORADO FORUM
It is currently Wed Dec 11, 2019 8:36 am

All times are UTC + 8 hours


We have NEW server almost ready, try it out here


Post new topic Reply to topic  [ 51 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6  Next
Author Message
 Post subject: Re: Ducks 13 Max build
PostPosted: Sat Jun 29, 2019 2:20 pm 
Offline

Joined: Sat Oct 12, 2013 5:36 pm
Posts: 1595
Duck
Is that position between the canopy/tray and the cab????
Like Danny, if it is there it isn't much good. Even aerials have to be around 300mm from each other so as not to interfere with the signal radiation much at all. One side of the vehicle might radiate ok, sort of, but out the other side and fore and aft will be shielded to hell.

If the surrounds are grounded to the base, then the radiated signal is basically short circuited.
Best place is above the roof if you want performance. Nice to have a good radio but it won't be able to demonstrate it's ability.
What sort of range do you expect to get. I took advice from the manager of electric Bug in Adelaide, Torrens road, and he said above the roof with a 4 Db aerial and it has twice received and transmitted at least 140km in good conditions to get emergency service request out there. Most people only think of a bit of communication, but for me, two people have been saved by having a decent setup. Normal phone use towers not there.


Top
 Profile  
 
 Post subject: Re: Ducks 13 Max build
PostPosted: Mon Jul 01, 2019 11:21 am 
Offline

Joined: Sat Apr 29, 2017 7:58 pm
Posts: 280
Location: Brisbane
Danno wrote:
Duck wrote:
Made up a bracket after much contemplation on where to put the aerial, didn’t want to get a front bar and didn’t want to use a z bracket. Yes there will be transmission loss because of placement but can live with it.
Now the radio


Won't work properly at all there mate. It'll work a bit and seem ok from car to car but over a distance it'll be crap, you'll be lucky to get a few hundred metres with it there in certain directions which is not much help if you're stuck somewhere and calling for help! (been there done that) you need to get it up higher and the more central the better, put it on a foldable base if need be. It's a black art but one rule of thumb is the antenna will only transmit as far as it can sort of "see" if that makes sense and 5k is about as good as it usually gets, however I can get up to 20k in my truck because it's so high on the mirror.


Yes I hear you I have thought long and hard, I have another mount up higher I can move it to on trips,
But will wait and see how it goes there.

In the new toy side my light bar turned up today again far from ideal for what I need but not toys are new toys. Thinking I might cut out the bumper to fit it in.


Attachments:
File comment: Stedi 32’ curved with drl.
4703877E-EF8F-4580-9C51-D9E62B3E0351.jpeg
4703877E-EF8F-4580-9C51-D9E62B3E0351.jpeg [ 406.39 KiB | Viewed 1275 times ]
Top
 Profile  
 
 Post subject: Re: Ducks 13 Max build
PostPosted: Mon Jul 01, 2019 11:45 am 
Offline

Joined: Sat Oct 12, 2013 5:36 pm
Posts: 1595
Duck
I understand that you find the aerial position convenient, but if the aerial is close to metal it completely upsets and alters the SWR of the radio/aerial combination. Any restriction to transmitting will see some of the signal power reflected backdown the coax and into the output transistors of the radio. Not a good idea. The worst situation is: With no aerial attached, all the transmit power is reflected back into the radio and it definitely stuffs the output stage by overheating it.
The picture of the lightbar is very hard to see what is what and it is on it's side too. I wouldn't be cutting the bumper skin to fit it.


Top
 Profile  
 
 Post subject: Re: Ducks 13 Max build
PostPosted: Mon Jul 01, 2019 5:05 pm 
Offline

Joined: Fri Mar 17, 2017 3:12 pm
Posts: 67
Location: Sunshine Coast
As MYDMAX has stated bigger is not better unless you have a SWR meter.

Go back to the 70's a 30 ft antenna wasn't practical on a 4x4 for 27 mg CB . Some still had a quarter wave or 9 Foot antenna .Still a pain. These days with UHF and VHF we have ground plane independent antennas . Thanks to marine use for mounting on fibrerglass.
Mount anywhere on the vehicle the longer the antennae better line of sight but smaller is better in hilly country city use.


Top
 Profile  
 
 Post subject: Re: Ducks 13 Max build
PostPosted: Mon Jul 01, 2019 5:37 pm 
Offline

Joined: Sat Apr 29, 2017 7:58 pm
Posts: 280
Location: Brisbane
Dmax do you think it will damage the radio ? It has pretty Todd view 3 directions but nothing back through the cab.
Can’t seem to resize the photos for viewing very well. It is a stedi curbed.
Why not cut the bumper? I didn’t want to block any airflow in the existing air intakes


Top
 Profile  
 
 Post subject: Re: Ducks 13 Max build
PostPosted: Mon Jul 01, 2019 8:50 pm 
Offline

Joined: Sat Oct 12, 2013 5:36 pm
Posts: 1595
Duck
No, I don't think it will damage it but the propagation of the radio wave pattern will be severely altered from what the aerial is designed to do. If any metal is close and/or inline with the radiating element it will reflect signal and change it's shape and also reduce the range. Just in convoy maybe ok but relying on more will be hit and miss, mostly miss.
You would get far better performance with a magnetic base unit on the roof I would suspect.

Perhaps you could make the required brackets and fit the lightbar and see if the airflow is affected to any degree with running hotter being the issue. If not then OK. Obviously don't place the bar in the airflow entry. I have seen some Dmax with a bulbar and covered in 1 long and 4 individual 12LED twin row lightbars and towing big vans which don't have a cooling problem.


Top
 Profile  
 
 Post subject: Re: Ducks 13 Max build
PostPosted: Mon Jul 08, 2019 5:26 pm 
Offline

Joined: Fri Dec 20, 2013 6:32 pm
Posts: 100
Location: Brisbane
Same light as me ??


Attachments:
P_20180727_154736_vHDR_Auto_HP.jpg
P_20180727_154736_vHDR_Auto_HP.jpg [ 476.6 KiB | Viewed 1200 times ]
Top
 Profile  
 
 Post subject: Re: Ducks 13 Max build
PostPosted: Thu Jul 11, 2019 7:13 pm 
Offline

Joined: Sat Apr 29, 2017 7:58 pm
Posts: 280
Location: Brisbane
mustangdude wrote:
Same light as me ??


How do you find the light?


Top
 Profile  
 
 Post subject: Re: Ducks 13 Max build
PostPosted: Tue Jul 16, 2019 5:14 pm 
Offline

Joined: Fri Dec 20, 2013 6:32 pm
Posts: 100
Location: Brisbane
Hi Duck,

I think you'll be happy. I am for sure.

It's sometimes too good when approaching a reflective sign, I have to low beam it.

The wiring supplied was good although I did shorten & modify it to my install.


Top
 Profile  
 
 Post subject: Re: Ducks 13 Max build
PostPosted: Thu Jul 18, 2019 10:27 am 
Offline

Joined: Sat Apr 29, 2017 7:58 pm
Posts: 280
Location: Brisbane
Currently have the front bumper off and making bracket up to mount, uhf is done & is ok.
Then it’s time to use it. Fraser is here I come.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 51 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6  Next

All times are UTC + 8 hours


Who is online

Users browsing this forum: No registered users and 0 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group