HELP with UHF/VHF aerial mounting

Re: HELP with UHF/VHF aerial mounting

Postby RHKTriton on Tue May 31, 2016 7:56 am

You can't use any TV antenna components, they are all 75ohm impedance whereas two way radio uses 50ohm.

Stick to simply swapping your antenna elements if you are moving through such diverse terrains. If you start with a 100% of signal, every metre of cable will cause loss, splitting the signal between two antennas likewise reduces the signal to and from each antenna. Even a two way switch causes some loss. Better to have one antenna working at maximum efficiency.

I find the 6dB whip is the best all rounder. I can communicate quite a few kms on the flat and in the hilly country its largely line of site.
Don't let the b'strds get you down!!
RHKTriton
Platinum Subscriber
 
Posts: 4335
Joined: Wed Jun 10, 2009 10:05 pm
Location: La trobe Valley - Gippsland


 

Re: HELP with UHF/VHF aerial mounting

Postby Cowboy Dave on Sun Jun 05, 2016 2:08 pm

So here's a question for the experts. I don't profess to understand too much about these antennas and stuff.

I have an elevated feed RFI antenna with the changeable whips, so a nice little short one for hill country and another longer one, 2 feet long maybe, that is 6db. I noticed at supercheap yesterday that they had a 6db whip that was closer to 5 feet long with some copper wound around strategic spots. I think it was fibreglass maybe, not too sure on that.

So if I have a choice between two whips, which both claim 6db, but one is twice as long as the other, will the longer one outperform the shorter one if mounted so that it reaches higher than the shorter one would?
The Hitchhiker's guide to the the Triton universe and NTN.

A how to on finding your own way - search me.

The two threads I wish people would use more: thing 1 and thing 2.
User avatar
Cowboy Dave
Moderator
 
Posts: 18098
Joined: Tue Dec 29, 2009 9:46 am
Location: Sydney

HELP with UHF/VHF aerial mounting

Postby snakesoup on Sun Jun 05, 2016 3:09 pm

the shorter whip that you have on its own " without the elevated feed" are nominally rated at 4.5db. the longer whip that you have described are nominally 6db on there own, if you add the long whip to the elevated feed, which I have also done, then it should give you better performance out in an open area, the little extra height will help also, with UHF there is a saying " height is might ". and this is very true, nothing will improve the performance of your radio and antenna than getting it higher up in the air, if you go and park on the biggest hill around that you can find, you will see how well it works, and can be quite surprising, believe me if you will, I don't care if you don't either but I have spoken from Gippsland vic from a large hill to Tasmania before on a yeasu handheld to guy that we could talk to regularly from our base station setups during the summer months


Sent from my iPad using Tapatalk
User avatar
snakesoup
 
Posts: 1115
Joined: Sun Feb 02, 2014 2:24 pm

Re: HELP with UHF/VHF aerial mounting

Postby Jacobie on Tue Nov 01, 2016 7:58 am

Not entirely sure if this question is relevant here but...

My UHF has all of a sudden stopped working, i looked at what my mate had done to wire it up...
By the looks of it, it powers from the UHF device itself, earth runs to an earth point (Okay), the power runs into the fuse box, runs to a fuse on the cable, which then runs directly to the fuse box. It was easy to unplug from the fuse box as it was pretty much just one of those C connectors. Just wonder how to get it working again or is it cactus? I plugged it back into the same spot in the fuse box as before and the fuse appears to be okay... Anything else I could try?
2013 MN GLX-R

Build Thread: Jacobie's 2013 MN GLX-R
User avatar
Jacobie
 
Posts: 396
Joined: Thu Dec 17, 2015 7:15 pm
Location: Ipswich, QLD

Re: HELP with UHF/VHF aerial mounting

Postby Cowboy Dave on Tue Nov 01, 2016 8:39 am

Connect a fresh power wire straight to the battery and see if that makes any difference. If it does then the existing wire or fuse or where it connects is the problem, but at least you've narrowed the possibilities.

Also move the earth to the battery while testing. For in cab earthing use one of the factory earths, they label those bolt heads with an E for earth. There is one at the bottom of the kick panel on either side which will take a ring terminal connection.
The Hitchhiker's guide to the the Triton universe and NTN.

A how to on finding your own way - search me.

The two threads I wish people would use more: thing 1 and thing 2.
User avatar
Cowboy Dave
Moderator
 
Posts: 18098
Joined: Tue Dec 29, 2009 9:46 am
Location: Sydney

Re: HELP with UHF/VHF aerial mounting

Postby Jacobie on Tue Nov 01, 2016 11:52 am

Thanks for that Dave, I will have another look tonight cheers.
2013 MN GLX-R

Build Thread: Jacobie's 2013 MN GLX-R
User avatar
Jacobie
 
Posts: 396
Joined: Thu Dec 17, 2015 7:15 pm
Location: Ipswich, QLD

Re: HELP with UHF/VHF aerial mounting

Postby MrCozy on Mon Feb 04, 2019 6:19 pm

Bumping this thread..currently I’m installing a GME TX 3500, with DIN mount kit, and 4.5db antenna..my plan is to mount to the passenger bonnet. Went to mount the z bracket today, and noticed the rail has ridge running down the center is where I need to mount the bracket..I probably already know the answer of what I need to do( flattening down where I need to secure through) but thought I ask first if anybody else had any further tips or hints? Also, pilot hole first, or just tex screws?


Sent from my iPhone using Tapatalk
MrCozy
 
Posts: 41
Joined: Mon Aug 20, 2018 10:05 pm

Re: HELP with UHF/VHF aerial mounting

Postby NowForThe5th on Mon Feb 04, 2019 7:55 pm

Years ago I used to buy a bracket specifically made for this issue from Dick Smith. Of course, they're gone now but a bit of Google searching may find someone else who has them.
Chris

If work is so terrific, why do they have to pay us to do it?
User avatar
NowForThe5th
Moderator
 
Posts: 8677
Joined: Sun Jun 15, 2008 2:00 pm
Location: Holt, ACT

Re: HELP with UHF/VHF aerial mounting

Postby 4wd26 on Tue Feb 05, 2019 9:04 am

depending on the model of triton, but be aware that the MQ has a very tight fitting bonnet and will wear through the "standard" coax cable very quickly (within a week if used on dirt/ rough roads)

got a local UHF specialist to fabricate up a fme connector/ adaptor
Getting Out There
Sucks to be you, glad I bought a 3.2 :o
User avatar
4wd26
Moderator
 
Posts: 8280
Joined: Tue Dec 18, 2007 3:00 pm
Location: Bayside Bundy and Monto

Re: HELP with UHF/VHF aerial mounting

Postby MrCozy on Tue Feb 05, 2019 3:34 pm

It’s 09 ml dual cab..has 3” high nudge bar, aftermarket and narrow, so not really keen to mount there, and is only 4.5db, not 6.6db antenna, so not sure reception quality at front , though would still be same mount height as bonnet mount


Sent from my iPhone using Tapatalk
MrCozy
 
Posts: 41
Joined: Mon Aug 20, 2018 10:05 pm

Re: HELP with UHF/VHF aerial mounting

Postby RHKTriton on Sat Feb 09, 2019 8:10 pm

Nude bar is usually a good spot, clear of body work.

Have you considered at the back of the cab?

A mount could be glued to the glass, letting the whip poke out above the roof line.

The technically optimum position would be to mount it in the centre of the roof. Hole through the roof above the dome light.

I've thought about using the car radio's antenna location as a possibility.
Don't let the b'strds get you down!!
RHKTriton
Platinum Subscriber
 
Posts: 4335
Joined: Wed Jun 10, 2009 10:05 pm
Location: La trobe Valley - Gippsland

Re: HELP with UHF/VHF aerial mounting

Postby MrCozy on Wed Feb 13, 2019 6:13 pm

Yeah, decided to go the nudge bar. Doesn’t look as odd as thought it might. Wish I had gotten the Axis bracket off eBay instead of the Aeropro one, as the Axis bracket has cable slot in it , but them’s the breaks I guess for wanting get done quickly

Now to just straighten the nudge bar.
Click to view larger pictureClick to view larger picture


Sent from my iPhone using Tapatalk
MrCozy
 
Posts: 41
Joined: Mon Aug 20, 2018 10:05 pm

Re: HELP with UHF/VHF aerial mounting

Postby snakesoup on Wed Feb 13, 2019 7:48 pm

Looks the goods mate

Sent from my SM-G920F using Tapatalk
User avatar
snakesoup
 
Posts: 1115
Joined: Sun Feb 02, 2014 2:24 pm

Previous

Return to Electrical

Who is online

Users browsing this forum: No registered users and 8 guests