More 2M Talk: Antennas

[articulate]

The influx of the 2M people is coming. Hang on tight. :rappel:
However, at least I am taking my exam next week. (AHEM!!! Ed. . .). But I gotta get on top of things here and get the hardware in place.

Alot of you boys have that slick antenna mount on your hood/fender junction. Like these guys:
http://www.markdstephens.com/el_camino_del_diablo/expo_2006/taco_snorkels.jpg

(I just like that photo, so I post it alot)

What's the scoop on that antenna mount? What's it called, who carries it, etc?

Thanks!
Mark

[pskhaat]

What's the scoop on that antenna mount? What's it called, who carries it, etc?


Trunk lip mount. Diamond makes one: http://www.rfparts.com/diamond/k412s.html

[DesertRose]

The influx of the 2M people is coming. Hang on tight.
However, at least I am taking my exam next week.

We're taking our exam Dec 2 at the Hamfest in Tempe - yahoo! No more cryptic messages across the CB. Now we can BE AFRAID in real time.

[Brian McVickers]

No more cryptic messages across the CB. Now we can BE AFRAID in real time.


It's pretty amusing to listing to the 2meter conversations about obstacles and reports of perilous life threatening trail conditions from the trail scouts and then hear on the CB "Ok, after the second turn you'll come to some rocks and, um, well, just stay to the right and go slow, you should be fine!"

Even better is the 2meter chat followed by the CB translation “Yep, camp is just up ahead” :camping:

[articulate]

Trunk lip mount. Diamond makes one: http://www.rfparts.com/diamond/k412s.html
:rockon:
Thanks



Now we can BE AFRAID in real time.
It's the only way to live.

[articulate]

It's pretty amusing to listing to the 2meter conversations about obstacles and reports of perilous life threatening trail conditions ...:camping:
While riding with pskaat, I recall hearing, "Brian, I need an update on camp."

No answer.

[stern, with anxiety now, repeated over and over] "Brian, I need an update on camp." And I don't even know if that user (AHEM!!!) even has a license.

Now, you thread derailers...tell me about your antenna mounts.

[pskhaat]

I'm too wimpy to do it, but remember, the best thing for your antenna is drill a hole in your roof and mount it there :)

[DaveInDenver]

I'm too wimpy to do it, but remember, the best thing for your antenna is drill a hole in your roof and mount it there :)
This is the way I have it now. I had them mounted on out the ARB for a while and had them along the fender lip for a while. The fender mount hit too much stuff along side the trail. The ARB mount was always in the way (remember, my truck is old and tired, I spend a lot of time under the hood...). I put both CB and ham whips on the roof, best upgrade I've ever done range-wise. I pick up simplex conversations from Ft. Collins, which is 35 miles away. Not so impressive until you consider that range is through a major urban corridor, unlike our contact out in Moab which had the advantage of vast nothingness.

[Brian McVickers]

Mark
My antenna is mounted to the ladder on my back door. Is mounted to the top rung of the ladder so almost all of it 99% is protruding up from the roof line.
The antenna mount is then grounded to the frame of the vehicle via a 12ga wire connected to a bare metal spot on the frame. Note - I have not yet had an official ground plane or SWR test on this setup.

The antenna came in a kit with whip, 18' of coax and a whip mount for about $35. I then bought a different type of mount for the location I used for $20. The kit was cheaper than buying the whip alone.

[crawler#976]

Mark,

I'm using a 1/4 wave mag mount up on the roof - works fine for repeater use (it hits Mt. Elden from Prescott easily at 25W, and at 5W from Chino Valley) and simplex out to 25 miles or so. So far it's done well off highway - I've yet to hit it hard enough to dislodge the magnet - the short whip is very flexible.

I am considering going up to a 5/8 wave to see if that will improve my simplex range a little - not sure it's really necessary tho.

[Ursidae69]

Now, you thread derailers...tell me about your antenna mounts.

I have a Hustler SF-2 antenna using a front fender mount, both purchased at HRO in Phoenix.

[pskhaat]

ham whips on the roof, best upgrade I've ever done range-wise

I really would love to see the performance. Diamond antenna on the ARB I can hit Tucson's Mt. Lemmon UHF repeater on 5 watts from 153 miles away as the crow flies. Wonder how I'd do on 6m DX with it on the roof???

[k6uk]

I'm using a mount from Larsen, that amounts to nothing more than an angled piece of metal with a hole in it. But the nice part is, it's screwed right into my body panel so it's very secure, and has a good ground. It's pretty low profile, more so than other mounts like it:

http://mikemillar.smugmug.com/photos/96257656-L.jpg

[DaveInDenver]

I really would love to see the performance. Diamond antenna on the ARB I can hit Tucson's Mt. Lemmon UHF repeater on 5 watts from 153 miles away as the crow flies. Wonder how I'd do on 6m DX with it on the roof???
Now that is amazing! No reason to bother messing with that.

Honestly, I'd be surprised if you could do that repeatably. UHF is very sensitive to tropospheric bounce, so with the inversions we get in the west, you can get periods of awesome range that will open and close suddenly as fronts blow through. Then again it's also possible that you get a good line of sight to the repeater and it's just one of those hard to identify situations that just happen. I remember a year or two ago where a couple of people were involved in an accident (think they were caught in an avalanche) down in the Sangre de Christos and all they had were FRS radios. As you know these are 0.5W UHF with crappy antennas. Someone heard their distress call up in Denver or something and called in help. They were getting something like 100 or 200 miles out of those that day. But it was during a downsloping storm and so the troposphere was almost ideal with a heavy band of wet air sitting above them and dry winter air below. It ducted their signal almost like a textbook.

Actually, the reason I think I'm working better is mostly that the antenna is higher and I get a more uniform pattern all around the truck. Mainly my contacts don't fade in and out anymore and that could easily seem like more range. I'm running a 1/2 wavelength on 2m and get 360 degrees of pretty much equal strength. About the only weirdness I get now is right before dusk in the summer and for about 30 minutes after the sun sets I can raise a repeater in Breckenridge from Denver. There is no way I'm getting l.o.s. transmissions, so it's gotta be bouncing probably due to the changing air temperatures as the sun goes down.

[jeffryscott]

What about a through-the-window mount? something like this?

http://www.universal-radio.com/catalog/hamantm/0546.html

or this one:

http://www.universal-radio.com/catalog/hamantm/3075.html

[DaveInDenver]

What about a through-the-window mount?

I've seen these, very common with cell phone antennas. They can be convenient for commuter vehicles, although you give up some efficiency with them over a hard mount. The do have higher losses as you go down in frequency. At 70cm they can work OK, but at 2m they are pretty bad. In terms of expedition duty they are also less rugged and to that extent unreliable. But on a daily driver that might see some limited trail duty they can be an option. These are will not work on solar glass (called passivated), which is glass that reduces UV and keeps internal temps down inside the car. Most cars in the past few years use this and so you might not get the two pieces to couple correctly if you have this kind of glass.

[jeffryscott]

thanks Dave for the fast replies. While I think it would make for a clean install, I was curious as to how durable it would be off-road with the abuse it would potentially take.

Simpler is probably better especially since its intended use is for off-road travel.

[Grim Reaper]

Biggest flattest piece of metal is always the best friend of an antenna. It’s called "ground plane".

It drastically increases the efficiency of an antenna. I run a mag mount on my hood right in front of my wife to piss her off..... no really with my truck (86 4Runner with sun roof) it is the largest flat conductive surface. Wife understand that. She knows it’s about the waves because I tell her all the time when she complains about it.

[BajaTaco]

What's the scoop on that antenna mount? What's it called, who carries it, etc?



Here are mine (http://www.bajataco.com/electronics/antennas/index.htm) They are Firestik hood channel mounts. On my Tacoma, they do keep the metal a little shiny right where they are mounted.

[articulate]

Here are mine (http://www.bajataco.com/electronics/antennas/index.htm)
Nice! Way to revive this. Since I started this thread, I may as well "close it" by showing what I've done.

My radio needed a dual band antenna, and these aren't compatible with the Firestick mounts that you have (hole is 3/8" I think). I have a Larsen NMO mount dual band antenna on a similar bracket, though:
http://www.markdstephens.com/frontier/mods/antenna_1.jpg

http://www.markdstephens.com/frontier/mods/antenna_2.jpg

Now I look like one of the cool kids, stylin' with my antenna up front. Thanks for the help everybody.