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  #51  
Old November 19th, 2005, 07:59 PM
vabiro vabiro is offline
Victor Biro
 
Join Date: Jan 2005
Posts: 20
John,

Check out This page They are even kind enough to use a Defender to model the antenna for you. This is the HF antenna I have on my Disco. It is OK, but not rugged.

Another alternative is the Ham Stick. Usually you have a single whip for each band. They are two parts: bottom half is fibre glass, the top a stainless whip. The whip colapses into the bottom part, allowing tuning and storage. There is a pretty good chance you would be using 10m, 20m or 40m if you're going to be mobile, so you would only require one or two whips.

But seriously, You may want to look at an Outbacker HF Antenna Here is the blurb:
Quote:
The go-anywhere mobile antenna - the unquestioned, all season, all climate, all terrain, HF mobile champion. INCLUDES HEAVY DUTY SPRING MOUNT
This 1.8 metre tall antenna, covers 80-75-40-30-20-17-15-12-10m, includes the WARC bands, and mates perfectly with all modern, 50 Ohm, HF transceivers. No antenna tuning unit, or base matching device is needed. When combined with OUTbacker's, (OSB) heavy duty, spring base, the Classic makes a very rugged and professional installation, which will last for years. Maximum power:- 300 Watts, PEP. Also available in a 500 watt version


Rugged enough for off-road, versitile enough for all bands. Looks like it was built to take a s*^t kicking:


Any mobile HF antenna is going to be a compromise between mobile functionality and performance, so they start off perfoming sub-par. Add in esthetic considerations and the ability to survive off-road and things really get funky.

If all else fails, you could try these guys

For VHF/UHF the Comet SBB-1/NMO is what I use right in the middle of the roof:


BTW, I'm not sure why you'd need a switcher. Most HF-UHF transceivers have two SO-239 connectors. One will do HF-UHF or just HF-6m, and the second will do VHF/UHF. Dyplexers or duplexers only are needed if you want to either break out the VHF/UHF or merge the two so that you can use a single antenna for everything, like with the ATAS-120.

Victor
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  #52  
Old November 20th, 2005, 06:53 AM
Mike_Rupp Mike_Rupp is offline
Mike Rupp
WZ7V
 
Join Date: Apr 2004
Location: Mercer Island, WA
Posts: 864
Victor, tell us more about the bands themselves and what types of communications you use them for.
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  #53  
Old November 20th, 2005, 06:53 PM
vabiro vabiro is offline
Victor Biro
 
Join Date: Jan 2005
Posts: 20
Quote:
Originally Posted by Mike_Rupp
Victor, tell us more about the bands themselves and what types of communications you use them for.

Mike,

The source for info on how they have carved up the use of each band can be found in the ARRL Band Plan at:
http://www.arrl.org/FandES/field/reg.../bandplan.html

If you're more graphicly inclined, there is a nice chart available at:
http://www.arrl.org/FandES/field/reg...ands_color.pdf

Having said that, it leaves a lot out. It doesn't tell you anything about how these bands are used, and by whom. Much of what decides who and why they use a band is based on the propogation of that band, or the way the radio signals behave. This can change based on geographic location, time of day, season, phase of the moon (no joke) and a lot of stuff that wouldn't answer your question.

If we look at what we are mostly concerned with in the off-road/Expedition world it is probably distress and communications.

If we look at distress frequencies there are several. You can see some listed here: http://www.tpub.com/content/istts/14...s/14225_25.htm. The key though is not to be on the right frequency (there may be no-one listening at the right moment) it needs to be the one that will allow you to contact someone. IOW the propogation has to allow you to talk far enough to reach someone that can help.

All this to say, that 2m, and 70cm just ain't goin'a cut it where many of us go. We may be able to talk to each other a few km away, but talking to someone dozens or hundreds of miles away. This is where the HF bands will be the life saver (literally).

I mentioned 20m as being a band you would likely need. It is one that I regularly listen to because it is where the Huricane trackers are exchanging infomation with ships (14.300MHz). They use this band because the propogation lends itself to speaking long distances, on a predictable basis. As a result it would also be a band you are likely to find someone on at band most times of the day.

I think it may be worth the effort getting your 5wpm upgrade to your ticket, but I also hear they are getting rid of the CW (Morse Code) and all bands will be available for licensed amateurs of any class. You may not be able to build a 1 KW linear amplifier, or sponsor a repeater, but you will be able to learn about HF hands-on, and learninng is what Amateur Radio is about.

As an asside, in Australia they really leverage HF in a big way. Here is an overview from New Zealand, and here is a plain language overview of HF SSB. It makes a lot of sense, and I'm surprised there isn't a more organised effort here in North America to do something similar. These are virtually un-licensed HF set-ups that are designed for the same purpose as the GMRS bands.

Cheers
Victor
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  #54  
Old November 21st, 2005, 08:43 AM
johnlee johnlee is online now
John Lee
K6YJ
 
Join Date: Sep 2003
Location: Torrance, CA
Posts: 16,148
Victor, thanks for the awesome info on the HF antennae and the bands.

I'm kinda digging that Outbacker antenna, as it claims no tuner is required even with the very wide bandwidth capability of that antenna. I'm not crazy about its looks but the bandwidth is awesome.
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  #55  
Old November 21st, 2005, 10:24 AM
koby koby is offline
Craig Kobayashi
KG6CK
 
Join Date: Sep 2003
Location: Orange, CA
Posts: 442
John, have you seen this one?

http://www.universal-radio.com/catal...tune/3702.html

That tuner would work with your 706 and is weatherproof. It's small enough that it could be hidden behind your spare wheel carrier.
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  #56  
Old November 21st, 2005, 05:30 PM
johnlee johnlee is online now
John Lee
K6YJ
 
Join Date: Sep 2003
Location: Torrance, CA
Posts: 16,148
Yeah, that's the tuner the guy at HRO had on top of his Chevy Astro van and hooked up to his Icom 706MkIIG and some kind of 5' tall fiberglass whip. The HRO guy had his all PTT'd out so that the tuner would work after depressing the PTT button for an instant. There would be a very short wait and then an audible beep and the antenna was tuned for that frequency. It was sweet.

The tuner is a manageable size too. It'll definitely fit inside the spare wheel carrier on a Disco. I think that would be a sweet set-up, since the tuner would basically be invisible with the spare on the carrier.

I doubt it would fit on my Mantec wheel carrier though. And I'm not so sure I want to mount an HF antenna on the wheel carrier. The main reason I want HF capability is for very long range, and for that I would want an optimal antenna mounting location instead of the wheel carrier. For the CB I don't care but for HF I would want the antenna on the center of my roof rack, and there's no way on earth I would mount that tuner on top of my roof. It's much too ET Phone Home for my conservative tastes.

Right now I'm leaning toward the two 14" baby antennae for regular use, and then that Maldol six-band antenna disassembled and held in reserve for emergency use. I'm on this wire antenna thing right now. When I look at a fiberglass whip now, I want to vomit just as much as when I see those ET Phone Home antennae. I'm digging the wires with the curly Q's in the middle. I don't know why. But I'm digging them.

But it's still up in the air and my head still hurts.
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  #57  
Old November 21st, 2005, 06:38 PM
vabiro vabiro is offline
Victor Biro
 
Join Date: Jan 2005
Posts: 20
John,

The AH-4 looks like the Icom version of the Yaesu FC-40 like I have. You're right it does fit right behind the spare tire on the disco.

You're also right about the effectiveness of mounting a HF antenna on the spare tire mount. It is very discreet. When I have my antennas off all that hints of their having been is the cover on the NMO mount on the roof. However, the problem is I doubt my ground plane is any good. The spare tire mount is mounted on the door, and uses nylon.

I think some work on the inside of the door, like bonding the mount bolts with strapping would fix that though.

The other problem with that style of antenna tuner: your mount for the radiating element must be within a foot or so of the tuner. And a piece of solid wire is used to connect the two. This really restricts your mounting options. I can't see a way to do anything on the Mantec wheel carrier, short of mounting the tuner inside and drilling a hole through the door, or running it outside somehow to feed a whip mounted on the tire carrier.

This introduces a whole pile of other stuff that probably just makes things complicated. Not what you want when your life may depend on it.

I think KISS is the way to go: The HamStick http://www.hamstick.com/9106.htm

At $25 it will cost you a lot less than the Maldol. In fact, you could probably buy a complete set of Hamsticks for what is cost for the Maldol.

Check out the Maldol review on eham.net at http://www.eham.net/reviews/detail/3388
and the one for the Hamstick
http://www.eham.net/reviews/detail/19

Just my $0.02

Victor
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  #58  
Old November 21st, 2005, 07:06 PM
johnlee johnlee is online now
John Lee
K6YJ
 
Join Date: Sep 2003
Location: Torrance, CA
Posts: 16,148
Yeah, those eham reviews of the Maldol are scary. I can see how that Maldol would loosen, given that there are so many pieces on it. It would be even worse offroad, with something that long heavy constantly swinging back and forth. If that were my only antenna, I would be more concerned than I am now because I envision that antenna would be for emergency use only, and I would mount it when my vehicle was stationary. For my chatty talk, I would use VHF and UHF. And if I had to go mobile during an emergency, who cares what happens to that antenna.

The hamsticks aren't doing it for me though. The cost really isn't a factor for me. I would want the ability to transmit on several different bands in an emergency, and carrying around even one hamstick would be a bit much, let alone several different ones.
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  #59  
Old November 21st, 2005, 09:33 PM
johnlee johnlee is online now
John Lee
K6YJ
 
Join Date: Sep 2003
Location: Torrance, CA
Posts: 16,148
Quote:
Originally Posted by vabiro
The other problem with that style of antenna tuner: your mount for the radiating element must be within a foot or so of the tuner. And a piece of solid wire is used to connect the two. This really restricts your mounting options.....

The guy at HRO with that Icom AH-4 tuner told me the same thing. I was really digging the function (not the looks) of his set-up until he told me that the tuner had to at the feed antenna feed point. That basically ended the AH-4 for me.

Victor, since you're the ham guru, here's a question you might be able to answer for me: do you know if the Icom AT-180 antenna tuner can be mounted inside the vehicle, away from the antenna feed point? Check out this pic, for example:




To me, it looks as if the AT-180 unit isn't weatherproof like the AH-4 unit. And Icom's promo shots illustrate the AT-180 right beside the 706:



And here are some pics of what appear to be people's actual mobile set-ups:






In those set-ups above, the tuner appears to be right next to the 706. Is the tuner shown right beside the 706 just for illustration purposes, or may the AT-180 be mounted right beside the radio (hidden from view and sheltered from the elements) and far away from the antenna feed point?

I really do want HF ability in my D90, but I just can't bring myself to mount one of those giant HF antennae.
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  #60  
Old November 22nd, 2005, 05:18 AM
vabiro vabiro is offline
Victor Biro
 
Join Date: Jan 2005
Posts: 20
John,

Ham guru I am not. I just happend to have researched this for an expedition to the Arctic I did earlier this year (http://www.landroveradventure.com/to2tuk/), where I was responsible for the communications aspects. The problem I was faced with was that although I had the ATAS-120 screwdriver antenna, I was worried about it freezing up and not tuning properly. There were too many moving parts exposed to the elements.

In the end the best thing seemed to be was to keep the antenna really simple and tune it to the required frequency. The resut was that I put the FC-40 behind the spare tire and used a 102" stainless steel whip.

Before I decided on the FC-40 I looked at a lot of different tuner/whip configurations. In the end is was down to the Yaseu FC-40 and 102" whip, or a LDG RT-11 (http://www.eham.net/reviews/detail/1422) with HamSticks.

I decided on the FC-40 because I could use any whip and it would be made resonant, including stretching out a long wire attached to the whip if neccessary to get the additional performance in an emergency. If that wasn't a consideration, the RT-11 would have been the choice.

If you'd like to use a whip that is resonant on the band (like the Maldol or Hamstick) but need to use it across a broader protion of the band, then the RT-11 is the way to go.

It is rugged, water resistant (in case you dunk it during a water crossing) smaller than the Icom AT-180 and simple to use. It interfaces with the IC-706* and the Yaesu FT-857/897/817. It has more memory and is faster. Basicly it does what you liked about the set-up the guy at HRO had: Hit the PTT and it tunes itself.

The other thing you can do is put the head unit up front, the transceiver some where else, and the tunner some other place else. The result is that you are able to fit all your equipment discretely. I like that in my installs too.

Victor
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  #61  
Old November 23rd, 2005, 09:18 AM
johnlee johnlee is online now
John Lee
K6YJ
 
Join Date: Sep 2003
Location: Torrance, CA
Posts: 16,148
So Victor, if I understand you correctly the LDG RT-11 may be mounted inside the vehicle and need not be mounted right beside the antenna feed point?
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  #62  
Old November 23rd, 2005, 12:19 PM
koby koby is offline
Craig Kobayashi
KG6CK
 
Join Date: Sep 2003
Location: Orange, CA
Posts: 442
damn, that could be the magic solution!
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  #63  
Old November 24th, 2005, 07:44 PM
vabiro vabiro is offline
Victor Biro
 
Join Date: Jan 2005
Posts: 20
Quote:
Originally Posted by johnlee
So Victor, if I understand you correctly the LDG RT-11 may be mounted inside the vehicle and need not be mounted right beside the antenna feed point?

John,

You got it. It uses coax and can be connected at either end: close to the radio or close to the antenna. Your choice.

It is sealed against the environment, so you could even do something like tuck it up behind the rear wheel and rear bumper. There's some wasted space in there that some of the expanded gas tanks make use of.

Victor
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  #64  
Old November 25th, 2005, 07:53 AM
johnlee johnlee is online now
John Lee
K6YJ
 
Join Date: Sep 2003
Location: Torrance, CA
Posts: 16,148
Wow. Awesome.
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  #65  
Old November 28th, 2005, 03:08 PM
johnlee johnlee is online now
John Lee
K6YJ
 
Join Date: Sep 2003
Location: Torrance, CA
Posts: 16,148
I went to HRO last Saturday and picked up my HF antenna. I got the Comet UHV-6:


http://www.universal-radio.com/catal...antm/4289.html


It's pretty ET Phone Home with the three different HF loading coils on there, but the antenna is very flexible and may be operated as a tri-band (6m/2m/70cm), tetra-band (6m/2m/70cm with only one HF coil on top), penta-band (6m/2m/70cm with one HF coil on top and another HF coil sticking out radially), or a sexa-band (6m/2m/70cm with one HF coil on top and two HF coils sticking out radially). The antenna has plugs for a total of six different HF coils, although I'm not sure if the antenna may be operated with six different HF coils attached simultaneously.

While the antenna can be ET Phone Home, it's pretty clean with just one HF coil on top. It basically looks identical to this one:




With the 10m loading coil on top, the antenna is 54" tall. The antenna is 38" tall with the HF coil removed, so it's a pretty handy tri-bander as well for 6m/2m/70cm use.

I also picked up a new handheld:


http://www.universal-radio.com/catalog/ht/0690.html


And also two antennae for the new T90A:


http://www.universal-radio.com/catal...ntht/3925.html
http://www.universal-radio.com/catal...ntht/0209.html


I don't know which is worse: PSA or HRO.
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  #66  
Old November 28th, 2005, 03:11 PM
koby koby is offline
Craig Kobayashi
KG6CK
 
Join Date: Sep 2003
Location: Orange, CA
Posts: 442
Quote:
Originally Posted by johnlee
I don't know which is worse: PSA or HRO.

LOL
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  #67  
Old November 28th, 2005, 03:13 PM
traveltoad traveltoad is offline
Aaron Shrier
KI6BCA
 
Join Date: Dec 2003
Location: San Fernando Valley
Posts: 2,628
Awesome!

You've got me looking at the FT-857D to replace the IC-208H...
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  #68  
Old November 28th, 2005, 03:51 PM
vabiro vabiro is offline
Victor Biro
 
Join Date: Jan 2005
Posts: 20
John,

I can't believe you thought the ATAS-120 was too... conspicuous, and then you bought that!

That just goes to show you: as my real estate agent friend says "Buyers are Liars".

Well it will probably work better than the ATAS, just make sure you ground the mount and transceiver really well. There is an excellent tutorial written by a very knowledgable amateur. It is at www.k0bg.com

Cheers
Victor
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  #69  
Old November 28th, 2005, 04:11 PM
johnlee johnlee is online now
John Lee
K6YJ
 
Join Date: Sep 2003
Location: Torrance, CA
Posts: 16,148
LOL. That ATAS-120 is too beaucoup for me. The body is too chubby and the whip is so long that I can't store it inside my truck. This UHV-6 that I got is pretty ET Phone Home with more than one HF coil on it, but with only one HF coil it's palatable to me. Also, I can disassemble it into several different pieces and store it inside the truck when I'm not using it.

Thanks for the link to that http://www.k0bg.com/ site. I haven't read it yet, but it looks to be superb. I bookmarked it and will definitely read it closely.

These pics are a little scary though:






ET Phone Home.
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  #70  
Old November 28th, 2005, 04:15 PM
traveltoad traveltoad is offline
Aaron Shrier
KI6BCA
 
Join Date: Dec 2003
Location: San Fernando Valley
Posts: 2,628
I think all those antennae on your truck would be ok John...




as long as you wear your Arai XD everytime you drive!
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  #71  
Old November 28th, 2005, 04:20 PM
vabiro vabiro is offline
Victor Biro
 
Join Date: Jan 2005
Posts: 20
John,

I couldn't agree more. I saw those pictures too. Not my cup of tea.

On the ATAS-120, I disagree on storage. I lay mine on the floor behind the back seat. No problem. There is a slight bend in the whip portion, but no problem.

BTW, the bull bar is actually a pretty decent location. It provides an excellent ground plane because it is bolted right to the frame of the truck. If your intention is to have a HF set-up mainly for emergencies it might be worth putting a mount there for occasional use.

Cheers
Victor
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  #72  
Old November 28th, 2005, 04:26 PM
traveltoad traveltoad is offline
Aaron Shrier
KI6BCA
 
Join Date: Dec 2003
Location: San Fernando Valley
Posts: 2,628
Quote:
Originally Posted by vabiro
BTW, the bull bar is actually a pretty decent location. It provides an excellent ground plane because it is bolted right to the frame of the truck. If your intention is to have a HF set-up mainly for emergencies it might be worth putting a mount there for occasional use.

Cheers
Victor

That may not be a bad idea, Victor. A triband antenna on the roof (70cm/2M/6M) and a mount on the bull bar for HF (10M +). I think I like it.
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  #73  
Old November 28th, 2005, 04:29 PM
johnlee johnlee is online now
John Lee
K6YJ
 
Join Date: Sep 2003
Location: Torrance, CA
Posts: 16,148
I haven't tested it yet, but right now I'm hoping that my roof rack will be a sufficient ground. Like the Disco Safety Devices racks, my rack's feet have rubber bumpers. But unlike the Disco Safety Safety Devices racks, my rack is solidly bolted to my rear ladder, which in turn is solidly bolted to the rear cross member. So I'm hoping my rack will be an adequate ground and there will be less wires to route for my antennae and lights. Time will tell on this one. I've got to do some experimenting.
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  #74  
Old November 28th, 2005, 08:59 PM
johnlee johnlee is online now
John Lee
K6YJ
 
Join Date: Sep 2003
Location: Torrance, CA
Posts: 16,148
Quote:
Originally Posted by vabiro
.....make sure you ground the mount and transceiver really well. There is an excellent tutorial written by a very knowledgable amateur. It is at www.k0bg.com

Oh my. RF Ground? DC Ground? Ground plane? Up to now, I had believed that these three were one and the same. LOL.

Still reading that site. It's a little too advanced for my little brain, but I'm trying to pick up what I can.
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