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eHam Forums => Elmers => Topic started by: AC2EI on January 20, 2010, 12:10:47 PM



Title: QRP antenna for Yaesu 817
Post by: AC2EI on January 20, 2010, 12:10:47 PM
I have just purchased a Yaesu 817 radio and am looking for a QRP antenna to take backpacking.  I am considering the Superantenna MP-1, Buddistick or PAC-1.  Does anyone have comments on either of my three choices or any other recommendations?  I am primarily an SSB operator on 40/20/15 meters.  

Thanx  -  Steve


Title: RE: QRP antenna for Yaesu 817
Post by: N6KD on January 20, 2010, 12:41:23 PM
My experience in going qrp while camping is that the best antenna is a dipole up as high as you can get it or as an inverted vee.  These small loaded antennas you mention don't work very well.  You have the disadvantage of a small signal to begin with - so you don't want to lose any signal with an inefficient  antenna.  You can build a light weight dipole with very small wire and a homebrew center connector (from plastic sheet or plastic tubing) and light weight coax.  You can also feed with 300 ohm line and use a small 4:1 balun at the transmitter side.
Many QRP stations use an end fed antenna for field use - but the impedance is high so you need an antenna tuner.  The G5RV also seems to work well and covers many bands - but again, you need an antenna tuner.


Title: RE: QRP antenna for Yaesu 817
Post by: N0NHW on January 20, 2010, 01:34:22 PM
I have had great success with the Par End-Fedz antennas while camping, hiking, and field day.  I carry the EF-10/20/40 version. No tuner, I just throw in in a tree or use my Spiderpole 12M (40 ft) fiberglass mast.  I also have an MP-1 and it works, but I find it difficult to tune.

See them at:
http://www.parelectronics.com/end_fedz.htm


Title: RE: QRP antenna for Yaesu 817
Post by: WA3SKN on January 20, 2010, 01:34:24 PM
You want the biggest antenna you can find!  However, I have a friend that has had good luck with a buddipole and using a "drag line", a single full size radial connected to the radio and running through his pants leg and following behind him.
73s.

-Mike.


Title: RE: QRP antenna for Yaesu 817
Post by: KC8VWM on January 20, 2010, 02:15:53 PM
It is true "bigger" antenna's have a direct relationship in terms of performance when operating QRP.

So I use a large multiband antenna system but yet, it still somehow remains lightweight, compact and completely portable.

You can see a FT 817 portable station example here:

http://www.eham.net/articles/21744


73 de Charles - KC8VWM


Title: RE: QRP antenna for Yaesu 817
Post by: M0JHA on January 20, 2010, 02:38:32 PM
check my /p dipole out . multibander ,cheap as chips,lightweight and very efficient..no atu. can be fed with cheap rg58 as the missmatch isnt worth mentioning so losses  are not worth worrying about.

http://www.m0jha.com/about120.html

the only thing i have had to do is maybe jiggle the antenna around slightly or move it away from objects etc to get the swr right down. it was tuned in the clear but sometimes if /p it may not be so may need a tweek.

small antennas /miracle whip, atx walkabout MP1 etc are fine and people do make contacts on them but why comprimise when theres no need..



billy


Title: RE: QRP antenna for Yaesu 817
Post by: KC8VWM on January 20, 2010, 03:02:27 PM
Nice website Billy!

73 de Charles - KC8VWM


Title: RE: QRP antenna for Yaesu 817
Post by: N2QGV on January 20, 2010, 04:10:52 PM
You will get all kind of responses, but if you invest in the Par 10/20/40 EndFed, you will not regret it. Back packing to me means you do not want to add an additional pack to carry the antenna. Go to the Par reviews here and take a look.
I also have a MP-1 and when I can, I will elevate the radials when groung mounting on a PVC steak. Also works great, but my preference is still with the little PAR.

73
Art


Title: RE: QRP antenna for Yaesu 817
Post by: N2QGV on January 20, 2010, 04:12:44 PM
Uggh, I should learn to type/spell.


Title: RE: QRP antenna for Yaesu 817
Post by: WB6BYU on January 20, 2010, 04:47:35 PM
I will agree with the others that a half wave wire dipole is lighter, cheaper, and works
better than most "portable" commercial antennas.

My backpacking kit fits in a small belt pouch, with dipoles for 80, 40, 20, 15 and 10m
and 30' of coax, and weighs around 1 pound.  The center insulator is connected to
one end of the coax, with wing nuts to attach whatever combination of bands I want
to use in a particular setup.  I tuned up the wires about 30 years ago in a local park
and have never used a tuner with it, in spite of some less-than-optimum installations.
I can also use the individual wires to make other types of antennas when I feel like
it - for example, a 40m quarter wave wire makes a full wave on 10m (with the addition
of one clip lead to bring it to resonance for SSB or two for CW.)

I use #22 or so stranded, insulated wire and RG-174 coax.  For portable operation
where weight isn't as important you can use #18 wire and RG-58 coax.  To save
weight you could drop down to #28 gauge.  I've tried magnet wire, but it tends
to kink and is harder to work with.  I also carry a number of 15' to 30' pieces of
mason's twine to tie the wires off with.  I've built version with spade lugs to change
bands, too, rather than using multiple dipole elements, but it doesn't quite give
me the same flexibility to put up just the 15m dipole, for example, when there isn't
space for something longer (though I've gone to using some electric fence insulators
that are like plastic carabiners, and allow the rest of the wire to be removed easily.)
For a deluxe version you can use Anderson power connectors, which are available
in a number of different colors - these make it easier to explain to someone else
how to configure the antenna for each band. ("Connect the yellow plugs and open
the blue ones to work 15m.")  Manual band changing is OK when you are going to
stay on one band for a while, and/or when the ends are easy to reach, but if the
feedpoint is up at 25' you won't be able to reach the 10, 15 or 20m switches by
just lowering the ends of the wires.  It is a good approach, however, for NVIS
work on 40, 80 and 160m, where you would tend to use one band for daytime and
switch to another one for the evening, or when raising and lowering the antenna
feedpoint is easy to do.

With some practice it takes me 10 to 15 minutes to get the full set of dipoles up,
and a bit less for just one or two bands.  But I'm usually backpacking where there are
plenty of trees (or I can get creative and use rock formations when not.)  In some
areas you may want to carry a telescoping fiberglass mast if you can't count on
finding antenna supports locally.)

I've also used long wires of various sorts - they can give a bit of gain and allow more
creativity for antenna designs.  You can build a tuner for it in a very small space.
Anything that lets you get your antenna up 30' or more off the ground will be a big
improvement over a vertical whip (unless you are sitting on the beach by salt water.)
But, for simplicity, the dipoles are hard to beat.


Title: RE: QRP antenna for Yaesu 817
Post by: VE7RWN on January 21, 2010, 10:20:03 AM
Check out my page for what I use for a dipole.
http://www.freewebs.com/ve7rwn/ft817.htm
I didn't describe it in great detail there, but fully extended, the antenna works well on 80, and the weight of the chalkline housings is heavy enough to toss over a branch in a tree. There are commercial versions of this setup available online. The tuner is not really required, since by reeling in a few feet of wire, the antenna can be made resonant for your frequency of choice. Simple, cheap, easy to deploy and retract, and easy to fix if something goes wrong.

Good luck, and 73
Rob ve7rwn


Title: RE: QRP antenna for Yaesu 817
Post by: W7KB on January 22, 2010, 08:45:47 AM
Ventenna makes a very nice portable vertical antenna for field deployment.It is the HFp vertical.Fits into a small carry pouch with accesories and can also be upgraded to a dipole configuration.Mine works FB from my backyard w/my 703+@10watts pep.Not a pileup buster,but a sturdy effective portable lightweight antenna for QRP ops.Check out the reviews on this website.W7KB.


Title: RE: QRP antenna for Yaesu 817
Post by: W1QZE on July 15, 2019, 08:46:13 AM
I agree that the wire antenna is the best option when possible.  I am using the Wolf River Coils (WRC) Take-It-Along (TIA) Silver Bullet antenna and have been surprised how well it gets out with my FT-817ND.  I have used it with just a grounding rod as a mount as well as the WRC tripod with counterpoise wires.  The counterpoise wires are superior to just a grounding stake but when there are restrictions that can't be overcome, I've made concessions.  (3 ea-33 foot long wires come with the antenna kit.)

Bert WH7USA



Title: RE: QRP antenna for Yaesu 817
Post by: KB1GMX on July 15, 2019, 10:22:32 AM
There is no such thing as a QRP antenna, only one that cannot tolerate high power.
Translated any any antenna that is reduced in size with loading coils will eat your
power.

The two suggestions either the PAR/LNR EF40/20/10 or a dipole center with a
set of cut and pretuned wires are going to always work best.

FYI the PAR can have a set of monoband wires precut for any band from
60M to 10M so its not limited to the Three bands as sold.

Any of the wire end feds or dipole think about what it takes to get
them aloft and practice it.  The end feds are easier as only one
end need to be up there (that can help when trees are few or
badly located).

Everyone goes Buddypole or Stick or makes their own.  Nicely made products
for the antenna erector set folk but physics wins as they are no more efficient
than many other shortend dipoles.  Their flexibility can be handy for difficult
sites (what, no trees!).

Verticals look cool but on 40m unless its 12 to 17ft tall the losses to the
loading coil and need for a counterpoise/ground radials adds to weight
and lowers efficiency.   Though some sites that may be a means to the
end (getting on the air).   Shorter loaded verticals can work some but
seriously they are eating your limited power.

For practical reasons the likely bands you will use are in the 60-20 and
maybe 17  due to the current solar conditions.  80m is good for short
haul using a low (less than 15foot high) dipole.

For VHF/uhf as the radio can...  6/2/70cm are best some form of
collapsible dipole (or moxon-yagi) that can be oriented for Vertical
(FM work) or horizontal (CW/SSB work).  They needn't be heavy and
from a hilltop a  short 6ft mast is more than enough height.  I have a
6M three element beam with a 6ft mast that weighs in at 6 pounds
with coax its only 3ft long in the bag.  Could still be lighter though.

Just thoughts on whats out there and how to take advanage of
simple.

FYI with the 817 and friends often a bigger battery (capacity not weight)
is well advised.

Allison


Title: RE: QRP antenna for Yaesu 817
Post by: AC2EU on July 15, 2019, 10:50:24 AM
I bring a 20 meter wire dipole when hiking. The whole thing including the the coax and string wind up nicely on one of those Home Depot power cord H racks. ( it even has a handle)  The other stuff is heavier and less effective ( at least in my experience).

https://www.homedepot.com/p/HDX-150-ft-16-3-Extension-Cord-Storage-Wrap-YLCR-9/301035624?MERCH=REC-_-PIPHorizontal3_rr-_-303037744-_-301035624-_-N (https://www.homedepot.com/p/HDX-150-ft-16-3-Extension-Cord-Storage-Wrap-YLCR-9/301035624?MERCH=REC-_-PIPHorizontal3_rr-_-303037744-_-301035624-_-N)


Title: RE: QRP antenna for Yaesu 817
Post by: KC0MYW on July 15, 2019, 02:28:19 PM

I have a 6M three element beam with a 6ft mast that weighs in at 6 pounds with coax its only 3ft long in the bag.  Could still be lighter though.


Might be derailing the thread a bit, but this sounds interesting to me. Is this a homebrew unit or something commercial? I would certainly like to get some more information about it and perhaps get a similar setup.


Title: RE: QRP antenna for Yaesu 817
Post by: WA3SKN on July 15, 2019, 04:20:44 PM
2010 post.
Simple dipoles as high as practical are usually the best choice.
73s.

-Mike.