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wesintl
04-12-2010, 02:40 PM
any reason not to open up the arb antenna mounts to 3/4 nmo? I really don't want to run a hatch mount (or hood mount) like the rest of the 80 crowd and I want to run this antenna http://www.rfparts.com/diamond/sg7900nmo.html

My little adapter won't work with the room between the bar and the hood on the 80.

I only plan to screw on the antenna when in use and the rest of the time use the nmo rain cover most of the time.

thoughts, likes, dislikes, attempts at thread hijack :confused:

DaveInDenver
04-12-2010, 03:06 PM
I have a couple of those ARB brackets. They are OK, but honestly I think for what they cost a piece of thickish aluminum sheet and two exhaust clamps works a lot better. I'll have to snap a photo of what I made. The ARB brackets are sorta awkward in the way they fit, at least on my truck. They had to point forward because they keep the hood from opening otherwise.

BTW, AFAIK that Diamond does not use an NMO mount, but it's an SO239 type. Those are OK, but I feel they are less weatherproof and more prone to breaking. It's also a >$100 antenna, which is pricey for a 2m/70cm dual bander.

And yeah, I think it's a fine idea. This is exactly what I do with my CB antenna, 99.999999% of the time it wears a little black aluminum NMO rain cap.

The only thing I found mounting stuff on the ARB like this is that it will not ground through the powdercoat and so you will probably have to run a ground strap from the mount itself to the frame or a bolt or something. I drilled a small hole and used a star locking washer that cut into the paint into a wire lug. I ran the ground to the bumper and ran another strap to the frame, so that the bumper itself was also grounded to the frame, along with the hood, fenders and cab.

treerootCO
04-12-2010, 03:34 PM
I have the Comet version of that antenna if you haven't bought the Diamond yet. $50 if you want it.

Item : CSB-790A
Description : 2M/440 MOBILE ANT 15OW 62 IN TALL 5.1/7.7 DB GAIN UHF MT
YOUR HRO PRICE $99.95

wesintl
04-12-2010, 04:26 PM
I have a couple of those ARB brackets.
I'm talking about the ones that are prewelded on the arb bar on the top. I'm guessing the are built for HF antennas which are more popular in OZ. I'm not buying the clamp on ones.

BTW, AFAIK that Diamond does not use an NMO mount, but it's an SO239 type. Those are OK, but I feel they are less weatherproof and more prone to breaking. It's also a >$100 antenna which is pricey for a 2m/70cm dual bander.
It says it's an NMO mount? http://www.rfparts.com/diamond/sg7900nmo.html I thought about running just a straight 2m antenna since I really don't plan to be on 440 but what the hell is $50 on a $700 set up...

I think the comet root listed below is an SO239 but I can't tell. :confused: I guess nmo and SO239 interchangeable?

I think i'll take it treeroot but I haven't fully decided on antenna and mounting.

nakman
04-12-2010, 04:51 PM
Don't do it, Wes! rock one of these babies on the side of the fender http://www.gamiviti.com/html/products_antennamounts.html :)

http://www.gamiviti.com/images/tallowpot/antennamount_installed_taco.jpg

DaveInDenver
04-12-2010, 05:32 PM
I'm talking about the ones that are prewelded on the arb bar on the top. I'm guessing the are built for HF antennas which are more popular in OZ. I'm not buying the clamp on ones.
My mistake, I forget that some bull bars have tabs on them. The Hilux bars do not and they use clamp on ones that are less than ideal. I would use the tabs personally, although Nakman's fender tabs are nice but you already have the ones.
It says it's an NMO mount? http://www.rfparts.com/diamond/sg7900nmo.html I thought about running just a straight 2m antenna since I really don't plan to be on 440 but what the hell is $50 on a $700 set up...

I think the comet root listed below is an SO239 but I can't tell. :confused: I guess nmo and SO239 interchangeable?

I think i'll take it treeroot but I haven't fully decided on antenna and mounting.
SO239 and NMO are not directly interchangeable, but you can get adapters from an NMO to an SO239 antenna. You can't go the other way, so the 'universal' mount would be an NMO on the bumper or fender (or roof). Then you can get adapters for SO239 (or sometimes called UHF), or 3/8" studs or whatever else. The one you linked is NMO, I just assumed since most Diamond antennas are not.

wesintl
04-12-2010, 05:47 PM
Don't do it, Wes! rock one of these babies on the side of the fender http://www.gamiviti.com/html/products_antennamounts.html :)


I'm not really sold on the hood mount... Are you sure it has been properly tested :confused: probably needs demo testing :rolleyes:

Seldom Seen
04-12-2010, 06:08 PM
The welded tabs, IIRC, have a 5/8" hole and are 3/16" thick. Even if you drill it out to 3/4" for a standard NMO mount, the tab is to thick and you won't have enuf thread engagement and the center conductor might not make good contact with the antenna. What you need is a MNO-100-UHFF from here: http://www.eur-am.com/nmo.htm

nakman
04-12-2010, 06:21 PM
I'm not really sold on the hood mount... Are you sure it has been properly tested :confused: probably needs demo testing :rolleyes:

to be clear, it's not a hood mount it's a fender mount. One of the biggest benefits IMO is that the antenna doesn't move when you open the hood, so no stress on the skinny coax. I believe they have been pretty well proven out, but I'll talk to the inventor about an additional demo unit.. :D

bh4rnnr
04-12-2010, 07:18 PM
I'm not really sold on the hood mount... Are you sure it has been properly tested :confused: probably needs demo testing :rolleyes:

Figure if they can hold up to Kurts bashing, they should work well:hill:.

DaveInDenver
04-12-2010, 07:37 PM
Love that photo Perry!

Inukshuk
04-12-2010, 07:46 PM
Even if you drill it out to 3/4" for a standard NMO mount, the tab is to thick and you won't have enuf thread engagement and the center conductor might not make good contact with the antenna.

Agreed. It is too thick. Been there, learned that the hard way.

Then I used a flat NMO bracket bolted to the tab because i had already run the cable. Wish I had known of http://www.eur-am.com/nmo.htm. But I was in a hurry.

wesintl
04-12-2010, 08:08 PM
now this is all coming back to me about why I did what i did on the 70. One of the things i hate about the nmo is you feed the wire though the hole so you would have to pull the dang thing all the way back out from the radio if you ever wanted to change it.

DaveInDenver
04-12-2010, 08:23 PM
now this is all coming back to me about why I did what i did on the 70. One of the things i hate about the nmo is you feed the wire though the hole so you would have to pull the dang thing all the way back out from the radio if you ever wanted to change it.
They make them with connectors.

http://www.pasternack.com/images/PE51020_DP.JPG

Inukshuk
04-13-2010, 07:52 AM
now this is all coming back to me about why I did what i did on the 70. One of the things i hate about the nmo is you feed the wire though the hole so you would have to pull the dang thing all the way back out from the radio if you ever wanted to change it.

That's what I thought too but it was only because the ARB bracket was so thick. With the right NMO mount it just pops in from below and is secured with a locking nut.

wesintl
04-13-2010, 09:24 AM
With the right NMO mount it just pops in from below and is secured with a locking nut.

I had the right nmo bracket and you had to feed it down though. it is not designed to pop in from below.

DaveInDenver
04-13-2010, 09:46 AM
I had the right nmo bracket and you had to feed it down though. it is not designed to pop in from below.
True, the mount is designed for sheet metal and it's intended to install from the top so that you don't have to tear the ceiling apart to get it in. Some might disassemble enough to work up through the bottom but most I don't think work that way. I use plain Larsen NMO-K type mounts and they would not fit through from the bottom.

Groucho
04-13-2010, 09:53 AM
It enables a good ground plane without having to drill anything.

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subzali
04-13-2010, 12:36 PM
Don't do it, Wes! rock one of these babies on the side of the fender http://www.gamiviti.com/html/products_antennamounts.html :)


I'll have to see if that'll work for my Tundra...I'm trying to figure out a way to get my radio out of the Land Cruiser and into something where I'll use it more!

Uncle Ben
04-13-2010, 01:00 PM
http://www.youtube.com/watch?v=UKd5hupXJVo
:lmao::lmao::lmao:;)

wesintl
04-13-2010, 02:31 PM
who sells rg-58 by the foot?

Seldom Seen
04-13-2010, 10:40 PM
who sells rg-58 by the foot?

The Wireman (http://www.thewireman.com/) Actually he sells 8X or mini 8. Roughly the same diameter as 58 but less attenuation at U/VHF freqs

wesintl
04-14-2010, 03:16 PM
Thx Brian. I was hopin to find local.. Does anyone know if HRO sell mini 8 or anything by the foot?

DaveInDenver
04-14-2010, 03:26 PM
Thx Brian. I was hopin to find local.. Does anyone know if HRO sell mini 8 or anything by the foot?
HRO sells bulk, although couldn't tell you specifically RG-8U/Mini or not. My guess is maybe not.

wesintl
04-14-2010, 03:32 PM
like 20ft bulk or 500 ft? lol

DaveInDenver
04-14-2010, 03:42 PM
like 20ft bulk or 500 ft? lol
LOL! By the foot, altho I'm sure if you asked they'd help roll the whole wooden spool to your truck.

Seldom Seen
04-14-2010, 04:36 PM
I've only seen pre-made cables, with pl259's on each end, at HRO but I guess it wouldn't hurt to give them a call.

wesintl
04-14-2010, 05:02 PM
I really only want one pl259 on.. then feed the wire through and solder the other one on.

I'll figure it out. maybe go out there sat and buy me a kenwood 710a and swing by roots house for an antenna. then find me a gps that will work.

wesintl
04-16-2010, 09:47 PM
they do have rg8 by the foot but I bought a 25ft pre-made section and i'm going to cut it in half and solder my own ends on. :D

wesintl
04-24-2010, 03:12 PM
1. PL259 to NMO mount
2. Larsen 2m antenna
3. Comet dual bander