Portable antennas

Discuss and share portable operating equipment and techniques. Photos are encouraged.

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Portable antennas

Postby KF7ATL » Mon Oct 24, 2011 3:35 pm

A friend of mine went to considerable time, effort, and expense to build a multi-band, supposedly portable, vertical antenna from aluminum tubing. He used modeling software, consulted with experts, etc. The result, if I am totally honest, performs quite well on the air but is a huge monstrosity that isn't all that portable. It takes 4-5 people at least 30-40 minutes to put up and, when disassembled stores in a wooden box that take two people to carry.

While surfing the internet I stumbled on a very simple wire vertical for 20 meters. It was simple to build and tune, works well on 20 meters without a tuner, and works okay on 15 and 10 meters with a tuner. One person can put it up in 5 minutes, and when taken down, takes up a space about 11 inches square and 4 inches high.

This got me thinking. For the time, effort, expense, and space requirements of my friend's antenna, I could make a separate wire antenna for each band I want to operate on, and for portable use still come out ahead.

I will be the first to admit that I am no expert on either antenna construction or portable operating. Do any of you have thoughts on this subject?


Garth, KF7ATL
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Postby N6EV » Tue Oct 25, 2011 1:53 am

Hi Garth..
Interesting topic that almost is a sub hobby in itself! While I don't do a lot of portable operating here.. I have vicariously through a close friend and fellow member K6TW (SKCC 6101). It seems he's gone through the gambit of antenna designs for porable operating. He hikes to most locations so weight and packability are big requirements. He's used lightweight colapsable fiberglass fishing poles (15ft extended) in a few designs. His latest designs have used Jackite (jackite.com) 31' fiberglass poles.
His most recent antenna was a 20 meter vertical moxon using one pole and spreaders.
He has now embarked on looking at a multiband magnetic loop design.

I'll see if I can get him over here to the forum to engage in the discussion.
73
Paul N6EV
SKCC 3358T / FISTS 1407 / NAQCC 2247 / CWOps 380
http://www.N6EV.com/
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Postby ys1rs » Tue Oct 25, 2011 4:31 am

Will follow with interest too.

Rob.
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Postby k8jd » Sat Dec 03, 2011 12:06 am

My rule of thumb is "the smallest QRP radio needs the biggest antenna".
I have operated portable on 40 and 30 M with MFJ rigs.
I made dipoles for those bands and can hang them in trees on a campsite in less than half an hour.
A small weight on the and of a rope can get up on a good tree branch with a toss or two and then haul the dipole on up.
73 from K8JD, SKCC 1395, Centurion 18, Tribune 12, Band Endorsements; 160, 80, 60, 40, 30M, 20, 17, and 10M

Ham radio is real Radio, CW is real Hamming!
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Postby kb4qqj » Sat Dec 03, 2011 7:30 pm

Hi Garth,
I guess I'm a bit biased since I design, build and sell antennas, and operate 80% portable. I think I've tried most everything at some point and have come to the firm conclusion that any metallic object will radiate when RF is applied and you can have fun doing it!! :-)
That said, if you are not into paying the bucks for someone else to work the magic, an endfed wire will overall out perform most any portable antenna. It is easy to deploy, no magic tuning, settings, counterpoises needed. If it is a half wave of the band operated, no tuner is required. It can be deployed as a sloper, an inverted"L", an inverted "V", a flat top, a half square or a vertical. When properly tuned as a half wave no counterpoise is needed. BUT you are limited to a mono band if it is a halfwave. Using a simple wire (easy home brew) tuner you can make a 33 foot wire work wonders. Everything you need to work the world will fit in a small luch bag. With what you find in your junk box added to 66.6 feet of #26 wire you can build a half wave tuner. Add favorite QRP kit, key, operator and a warm/cold beverage ( weather dependent) and leave that foot locker at home... hi hi Just my thoughts, your mileage may vary.
There are many portable antennas that work well and are easily transported. From a small speaker wire doublet to a standard half wave dipole. I personally prefer the 5 band no tune doublet or my PAR EndFedz 20/40 dual bander. I don't leave home with out them.

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Postby W5ALT » Sun Dec 04, 2011 6:51 am

And just to show that I totally agree with Randy's evaluation, here's what I use when I travel internationally and don't want to carry much. It does work quite well, fits in a pocket and needs no tuner. It's essentially an off-center fed half wave doublet.

http://www.comportco.com/~w5alt/antennas/index.php?pg=4

73,
Walt, W5ALT
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Postby Guest » Sun Dec 04, 2011 7:59 am

Well Done Walt!!
Got to hand it to the wives, they may not no correct nomenclature, but they sure have a way of thinking out of the box. I would never even considered the trash can/ toilet brush angle. Way too far from the hardware/electrical departments!! LOL
I have used those Radio Shack "reels' on many projects. Alas, I can find them no more. I troll the RV stores looking for portable close line reels...
Great ideas and great work.

Randy
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Postby n3pdt » Sat Jan 14, 2012 8:52 am

I'm not the most experienced portable op, but have been out a number of times over the last year and a half and have formed some opnions from my outings. Randy's suggestion of an end fed wire is, of course, spot-on in my experience. The antenna choices in my portable kit are a 40-some' wire, and 3 more 27' wires. (for a counterpoise just because that' what seems to work the best for me), and I also use the standard NorCal doublet constructed from computer ribbon cable and suspend it from a 20' Black Widow crappie pole when a suitable branch isn't available.

My K1 has a tuner, but I also bring a Z match tuner that I use, and like, on my mono bands QRP rigs. THe Z match was a kit from Emtech.
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Re:

Postby KF5CSW » Mon Jul 09, 2012 6:00 pm

Can someone point me to the plans for one of those homebrew tuners? I'm curious to know how complicated it would be for a first-time project :)

[quote="kb4qqj"]Hi Garth,
I guess I'm a bit biased since I design, build and sell antennas, and operate 80% portable. I think I've tried most everything at some point and have come to the firm conclusion that any metallic object will radiate when RF is applied and you can have fun doing it!! :-)
That said, if you are not into paying the bucks for someone else to work the magic, an endfed wire will overall out perform most any portable antenna. It is easy to deploy, no magic tuning, settings, counterpoises needed. If it is a half wave of the band operated, no tuner is required. It can be deployed as a sloper, an inverted"L", an inverted "V", a flat top, a half square or a vertical. When properly tuned as a half wave no counterpoise is needed. BUT you are limited to a mono band if it is a halfwave. Using a simple wire (easy home brew) tuner you can make a 33 foot wire work wonders. Everything you need to work the world will fit in a small luch bag. With what you find in your junk box added to 66.6 feet of #26 wire you can build a half wave tuner. Add favorite QRP kit, key, operator and a warm/cold beverage ( weather dependent) and leave that foot locker at home... hi hi Just my thoughts, your mileage may vary.
There are many portable antennas that work well and are easily transported. From a small speaker wire doublet to a standard half wave dipole. I personally prefer the 5 band no tune doublet or my PAR EndFedz 20/40 dual bander. I don't leave home with out them.

Randy_KB4QQJ[/quote]
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