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Posted: 9/12/2011 11:00:31 AM EDT
Can anyone direct me to a thread where this has been discussed and if not does anyone have any recommendations or ideas for an efficient system that is quick to setup/ take down. Would like to have it function on 20, 40, and 80. No tuner in radio or external and would like to keep equipment needed to operate to a minimum. I've seen the Buddipole and so far that's the closest system I've found. Thanks.
Link Posted: 9/12/2011 11:15:21 AM EDT
Originally Posted By rangerm1a:
No tuner in radio or external

Not going to happen.
Link Posted: 9/12/2011 11:33:12 AM EDT
You could homebrew something like the Diamond BB7 that's basically a dummy load that radiates a little. But it won't be efficient. A whip and auto tuner like SGC makes would work, but efficiency will suck depending on length and with no radials it will still suck. And you said no tuner.

That's a tough one.
Link Posted: 9/12/2011 12:06:28 PM EDT
what about This Walkabout?

or This from MFJ
Link Posted: 9/12/2011 12:17:46 PM EDT
Originally Posted By rangerm1a:
Can anyone direct me to a thread where this has been discussed and if not does anyone have any recommendations or ideas for an efficient system that is quick to setup/ take down. Would like to have it function on 20, 40, and 80. No tuner in radio or external and would like to keep equipment needed to operate to a minimum. I've seen the Buddipole and so far that's the closest system I've found. Thanks.



Whoever comes up with this will find it very lucrative.

Yeah, the Buddipole is close.

If you can hang the antenna between trees you can do even better. This... along with a line launcher of some sort, some paracord. It will get you 80, 40, 20, 17, and 10 meters. You still need a tuner.

http://www.ar15.com/forums/topic.html?b=10&f=22&t=632450

Here's a field test of a similar commercial version, the shorter 66' 40 meter model.

http://www.youtube.com/watch?v=z3gaj1YjPkg

Link Posted: 9/12/2011 12:45:47 PM EDT
Good topic Ranger! I am working on this one right now as well.

You can make a relatively simple, light antenna that will do 80, 40 & 20, but not at the same time. By using a modified version of this antenna (the first two pics), and a hand winder you can deploy it fairly quick in hilly terrain or with a few trees at just over head high level. I made up four plastic spreaders like in the pic and used an analyser to set points on electric fence wire for different frequencies. Unroll the dipole to the frequency, pull the antenna tight and you are on. Made the 80 meter net all over the North Island and half the South Island on 20 watts with this. You need to get the frequency rolled out just right for it to work without a coupler and it is a very narrow band width so you will need to adjust the antenna if you want to move far on the frequency. I am going to make a few more mods to this antenna including making the ladder line section from insulated wire. I also use less wire resulting in a shorter ladder line since this is an expedient antenna that will not be up high.

That is why you should get a matching unit. For a manpack rig I started out with this blokes design but replaced the antenna tuner with an SGC 211 coupler. It is lighter, smaller and will match a huge range of loads for five years from the inboard AA bateries. It also allows frequency mobility fast enough for ale use once the coupler has a match on each band. The SGC will also tune a 8 foot whip. I am purchasing an AT 271A folding whip and with a 43' drag line is supposed to give a decent signal on 80. I will let you know when I try it.
Link Posted: 9/28/2011 6:55:25 PM EDT
Here is an interesting antenna with step by step instructions for 80 thru 30 and no tuner required. He also sells a commercial version for 40 thru 10.

http://www.alexloop.com/artigo19.html

I have been reading quite a bit about magnetic antennas lately and am about to start experimenting. Here is a large link base for mag loop antennas. It took me quite a while to get my head around the small loop (short circuit in dc) exciting the larger loop like a transformer.
Link Posted: 9/28/2011 7:52:35 PM EDT
Originally Posted By tagar:
Here is an interesting antenna with step by step instructions for 80 thru 30 and no tuner required. He also sells a commercial version for 40 thru 10.

http://www.alexloop.com/artigo19.html

I have been reading quite a bit about magnetic antennas lately and am about to start experimenting. Here is a large link base for mag loop antennas. It took me quite a while to get my head around the small loop (short circuit in dc) exciting the larger loop like a transformer.


it does require a tuner but the tuner is build in. thats what in that black box if your look at the pics and read the description. you would have to have the parts to build not only the antenna but also the tuner. you should be able to build it for less than the $266 shipped his is asking though.
Link Posted: 9/28/2011 8:02:41 PM EDT
I've got a Buddipole with a tuner...it's the best combo I've found for the operations you're describing.

A G5RV antenna in the band of your choice is also another good option.
Link Posted: 9/29/2011 10:40:24 AM EDT

Originally Posted By SuburbanDadSurvival:

A G5RV antenna in the band of your choice is also another good option.

The ZS6BKW is an improved version of the G5RV and supposedly doesn't require a tuner.

http://www.nonstopsystems.com/radio/ZS6BKW.pdf
Link Posted: 9/29/2011 1:02:55 PM EDT
Originally Posted By mylt1:
it does require a tuner but the tuner is build in. thats what in that black box if your look at the pics and read the description. you would have to have the parts to build not only the antenna but also the tuner. you should be able to build it for less than the $266 shipped his is asking though.


Well, sort of. It is actually a variable capacitor which is required for any magnetic loop antenna. 99% of the site referenced above is actually step by step home brew of this type antenna rather than sale of units. He even has instructions for making the capacitor. I just priced up a more robust set of plates for a capacitor made from laser cut 1.5mm ali sheet. This is for a vehicle based antenna like the stealth, rather than a man portable one which is why the plates are so thick. The magnetic antenna claims near dipole efficiency in a handheld antenna package for 40 thru 10 which is pretty good and far better than will be achieved with coil loaded poles and with a lot less set up.

I received the AT271 antenna and was impressed with the design. Just fling it out and give it a shake to lock it to full 10' tall. Clipped on the analyser with no counterpoise and got the expected swr in the higher bands. What was unexpected is when I clipped on a counterpoise, in this case a 25' wire I had, the swr showed another dip around 1.7 way down around 8megs. I will see if I can use a roll out counterpoise to get a decent swr on 80 up without the SGC 211. If so this would provide a handy backup. I don't know how efficient this antenna will be, probably no better than a buddypole, but it should provide the ability to make some kind of contact on the move down to 80m.
Link Posted: 9/29/2011 6:07:37 PM EDT
Man portable with no tuner on 80-40-20 sounds like a simple adjustable wire dipole (i.e. clothesline style) and some paracord. Of course it depends on your communications objectives and all the other factors. But if I were not too old and broke down to manpack I would still want to avoid weight and bulk so I would probably start with a modern QRP rig and a fullsize wire antenna such as the clothesline would be.

But being old and broke down has some advantages and for me, portable operation is driving to a site then carrying gear some number of yards to an operating position (if not already set up in my camping trailer). Therefore I can afford the weight and bulk of a hundred watt rig and a selection of antenna materials & accessories, and I just love my SG-237 autocoupler, the brick that it is. All together it pretty well stuffs a footlocker but it does the job!
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