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Author Topic: Best portable antenna  (Read 1144 times)

K2WPM

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Best portable antenna
« on: October 18, 2021, 07:04:08 PM »

I use a linked dipole, generally in inverted vee.  This weekend during NYQP and POTA Support Your Parks, I activated a couple rare NY counties and not-so-rare parks.  Did over 300 QSOs in five hours on air, mostly with good pile-ups.  But I spend an hour setting up, and an hour taking down.  I wonder if using a vertical ... Wolf River style ... would reduce the down time.  What are people's experiences and observations on different antennas?
David, K2WPM
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AE0Q

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Re: Best portable antenna
« Reply #1 on: October 18, 2021, 08:45:20 PM »

But I spend an hour setting up, and an hour taking down.  I wonder if using a vertical ... Wolf River style ... would reduce the down time.  What are people's experiences and observations on different antennas?
David, K2WPM

I use a trailer hitch mount to support a 32 ft fiberglass collapsible mast.  The fastest setup antenna I use is a single-band, 20m EFHW (32 ft long) up the mast, with a CMC between two sections of coax from the 49:1 xfmr to the radio.  Just takes a few minutes to have it on the air, AND it is fairly low profile in that not much horizontal space is needed.

I can change the wire on the xfmr to a 63 ft for a 40m-10m EFHW supported in the middle like an Inv-V, that takes a few minutes longer to unwind and pull out the ends but no more than 10 minutes to be on the air at a park :-)

A drive-over mount would also work instead of the trailer-hitch mount.

The Wolf River Coil antennas seem to be used a lot as a base-loaded vertical mounted close to or at the ground, not the most efficient setup (signal-wise) but they look cute...

Glenn AE0Q
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N2TO

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Portable Antennas
« Reply #2 on: October 19, 2021, 06:45:42 AM »

Hi David,

Congrats on NYQP last weekend.

I too setup antennas as inverted-vees when portable. My favorite is 67' doublet fed with 450 ohm stranded ladder line to MFJ-901B tuner. This is my go to if I can. Operate 40 through 10M. MFJ-259 analyzer makes tuner adj easy.

Next are single band dipoles, 1:1 CMC, RG-8X to rig. I'm about to make a new antenna, like yours.

Next W3EDP, 85' end-fed wire to MFJ-901B or MFJ-929 tuners, but use quarter wave raised counterpoises for bands to operate. Setup as an inverted-vee as high as possible.

Next have-wave end fed for single band to operate to tuners, single raised counterpoise to tuners. Inverted-vee for lower freq or vertical/slanted, etc.

I've used 40M vertical delta loops fed with ladder line to MFJ-901B but they require a lot of space. I loved them but top corner needs to be really high and they too take time to setup. Have tilted them, too.

GL

73 Kevin N2TO
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WB6BYU

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Re: Portable Antennas
« Reply #3 on: October 19, 2021, 09:52:39 AM »

Quote from: K2WPM

I use a linked dipole, generally in inverted vee... 



In my experience, the dipole has given the best combination of
simplicity and performance.  I tried a vertical wire on 20m and 40m
for Field Day this year, and it just didn't seem to work as well.

For my purposes I generally put dipoles for multiple bands on
the same feedpoint, so I don't have to fuss with the antenna to
change bands.  (That comes in handy when holed up in a tent
during a bad storm.)



Quote

...But I spend an hour setting up, and an hour taking down...



That certainly seems excessive, although it depends on the
circumstances.  I've spent longer than that putting up portable
antennas, but generally that would be for Field Day when
performance is more important, and we are trying to get a
big antenna up high in the trees.

I have been planning to make a video for my website on
setting up a portable dipole, partly to show that it needn't
take very long.  But I haven't managed yet...


Of course, the time spent depends on the circumstances, the
available supports, your physical abilities, the equipment, etc.
In some cases, an hour might seem pretty fast.

As an example, I recently operated from a parking area.  I used
a drive-on mount to hold the base of a 30' telescoping fishing
rod, tied a pulley and halyard to the next-to-top section (since
the top section is too flimsy), raised it up into position, attached
a dipole feedpoint and with wires for 20m and 40m to it, strung
the wires (and tie-off ropes) along the ground in the desired
directions, hoisted the feedpoint, tied off the elements, and
plugged the coax into the radio, all in 10-15 minutes.

So the first question is, what seems to take the most time?
Is it choosing a spot to set up?  Untangling the rope and
wires? Erecting a mast?  Getting a rope over a tree branch?
Pounding anchors for guy ropes?  Fixing the joints of your
telescoping mast so they don't slip down?  Or just lack of
practice or optimization?


From my experience, I would recommend two rules
to start with:

1) keep the wires and ropes from getting tangled
2) keep the antenna light

I solve #1 by winding all the ropes and wires in a figure-of-8.
This allows me to untie a bundle of wire and walk through
the woods stretching it out, with minimal tangles.  I've tried
various winding boards and such, but most don't allow me
to pull it out without twisting or tangling.

(Coax of RG-58 size or larger generally gets coiled instead, but
with alternating directions so it doesn't get twisted.)

#2 not only makes it easier to carry the antenna for backpacking,
but means that the wires are more flexible, and the supports
don't need to be as heavy, etc.  My old backpack dipole kit used
#22 stranded, insulated hookup wire, and that is quite adequate
at 100 watts.  Now I'm using #26 in many cases, which is still
good enough.  The ropes are sized accordingly...  well, somewhat.
While 550 paracord is great stuff for many uses, the 95 paracord
(or even microcord) is quite adequate for antenna use, or any
other thin cord, like mason's twine or fishing line.  I do have to
admit, however, that my eyes aren't as good as they were
40 years ago when I originally made up the kit, and I now like a
slightly fatter rope that I can see to untie - at least 1/16 inch or so.

The light antenna reduces stresses on the supports.  You don't need
to pull up much tension on the wires, so the end ropes can be tied
off to something as simple as a clump of grass.  While I have some
of the 4' military mast sections, I don't need anything
that strong for a dipole.  I find 3/4" sectional aluminum tent poles
are quite sufficient (depending on how high I am trying to get it),
and much lighter.

Here in NW Oregon, trees are often convenient for use as antenna
supports.  I use a throwing bucket,
which is simple, works well up to 50-60' or so, and isn't quite as
concerning to other folks enjoying the park as some of the other
options that are sometimes used.

If you aren't used to tying knots that will hold (and that are
easy to untie), then consider some of the alternatives
that make it easier and faster.  (Although learning to tie some
useful knots is a good backup.)


So I'd encourage you to look at what is taking so much time,
and how you can improve it.  In my experience, saving setup
time by planning and practice makes a huge difference in
how enjoyable portable operation is.  And, especially when
operating QRP, I wouldn't want to take the performance hit
of switching to a loaded vertical, because my improved
ability to make contacts on a dipole will more than make up
for any difference in operating time gained by using a
vertical instead.  (But this may vary, depending on the
stations you are working, distances, power level, etc.)

VK3YE

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Re: Portable Antennas
« Reply #4 on: October 19, 2021, 01:15:55 PM »

What's the quickest QRP portable antenna?

I suppose the quickest is a magnetic loop that you carry around with zero setup time.

A simple vertical with a extendable pole takes about 2 or 2 minutes to erect.

https://www.youtube.com/watch?v=WHCNNRX8944

https://www.youtube.com/watch?v=RlvW9f--JOI

Add a little more time if you have to hammer a stake into the ground, need multiple support poles or (especially) if you use radials.

Radials are also a hassle in public places where there's other people walking nearby.

Something else I suggest avoiding are antennas that need trimming for different sites and configurations.

Instead use something without loading coils and traps if possible. Use an antenna coupler right at the end of the antenna instead.

My overall favourite is about 20m of wire set up with a pole in the middle to form an end-fed inverted V. On 40m this provides a roughly
omnidirectional pattern. On 20m it's quite a good broadside radiator.

A recent outing where I used one to work Europe on 20m SSB is here:

 https://www.youtube.com/watch?v=XztHzY_ed7k

More ideas on my video playlist at https://www.youtube.com/watch?v=bN-9LVQTYWs&list=PLj8-NKcZtRf6vQ-s5qvvrRjumICN_GRpH

Or website at https://vk3ye.com/projects/projwire.htm
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Peter VK3YE/AK3YE    Youtube videos at VK3YE

Author of 'Minimum QRP', 'Hand-carried QRP Antennas', 'Ham Radio Get Started' and other popular books on ham radio.
All available in paperback or $US 5 ebook. Learn more at vk3ye.com or 'VK3YE Radio Books' on Facebook.

K3XR

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Re: Re: Best portable antenna
« Reply #5 on: October 20, 2021, 08:46:10 AM »

Just returned from a weeks camping in one of the Pa state parks where I do most of my camping 4-5 weeks every year. 

My set-up for portable operation is as follows.
Spiderbeam 40 ft. HD push up fiberglass mast. (attached to spare tire mount )
ULTIMAX DXTREME  33 ft end fed antenna attached to the mast
two 33ft counterpoise wires
Kenwood TS-480S 
Computer for digital modes with a USB GPS receiver for accurate time.

I have used a number of different antennas over the years and have settled on this arrangement as my preferred portable antenna.  Using the antenna tuner in the Kenwood it performs very well on 40-6 meters.  Last time out doing just casual operation worked about 60 stations on a number of different voice, cw and digital modes.
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K0UA

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Re: Portable Antennas
« Reply #6 on: October 21, 2021, 09:03:02 AM »

One of the quickest to deploy portable antenna I use is a modification of my mobile setup. The truck is a 2010 Silverado Extended cab, so it is a pretty big chunk of counterpoise. Just drive up to your portable operation location. Then from under the back seat, grab the 4 foot long fiberglass "fishing pole" that I have modified with a wooden block that fits the bed stake hole.

Attach a 25 foot length of wire and plop the extended pole (now 20 feet tall) into the far diagonal stake hole and attach the other end to the existing mobile screwdriver antenna's whip. This in effect give you a 25 foot whip for 80, 60, 40, 30 meters. for 20 meters the wire has a small plastic insulator with the wire having automotive spade connectors so the wire can be shortened to about 15 feet electrically. This allows the extended wire to be near 1/4 wave on 20 meters. 

Of course the movable inductance of the screwdriver antenna itself will tune these wire lengths on the various bands. The tuning locations of the coil will be vastly different than the normal locations with the stock whip.

What is the advantage of this "extended whip"?  Many dB's of gain. I have seen up to 18 dB of gain on 80 meters. Of course when you start with a very inefficient antenna to begin with (Little Tarheel II on 80 meters for example) you can achieve some real gain by lengthening the whip.  you could also toss even more wire over a tree limb on the lower bands and tune it with your screwdriver antenna.

You can operate from the truck, but in the events I have participated in. we operated from a table with a battery and a length of coax going back to the truck. This setup was in a parking lot of a store with many other exhibitors adjacent to our operation.

Advantages of my portable operation idea is very quick deployment, No need for radials, as the truck provides the counterpoise, and while not as efficient as a dipole or inverted V in trees, my arrangement does not require any trees or supports of any kind, there is nothing for the general public to trip over or touch. My setup though is many times more efficient than just a mobile whip, and likely many times more efficient than some other low verticals with tripods and loading coils that would need radials.

As long as the extended wires are kept shorter than a natural 1/4 wave (capacitive) then the motorized loading coil of the screwdriver antenna should be able find a good match.
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73  James K0UA

KB1GMX

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Re: Portable Antennas
« Reply #7 on: October 21, 2021, 09:51:52 AM »

For portable or fiel ops I prefer to stay near full sized antennas and if
possible high enough to perform well.  That said...

For 6M and up beams 2 to 15 elements.  On 432 15 elements is barely 8ft.

For HF my field kit includes..
-Rectangle for 10M 12ft high 6ft wide and easily hung from a branch 20Ft up.
-For other bands Endfed Half wave monobands for for 40, 20 and 10 are
 small L-network feeds (small box) with half wave wire. Also a PAR EF-40/20/10
 for work to 25W (50w SSB).
-For locations that do not favor any kinds of wires (flat or no usable trees/support)
then a vertical as long as possible ( up to about 17ft) with large tapped load coil
clamped to something large and metallic (chain link fence post) or ground
mounted with 6- radials.

That packs to a compact kit that goes with me in the truck.  It allows me to
improvise a large assortment of antennas that can be more optimal for the
location than a standard box solution.

The mobile has a bunch of 8ft(ish) center loaded whips for in motion for 80-10.
It also has a fixed mast that I can add up to 20ft of sections to for a total of
24ft as a point to support one end of a wire antenna.  The other is not available is
a 20ft crappi pole. Generally where possible I prefer antennas that are not
shortened more than 50% as shorter than that the efficiency plunges.

Going from a 8 ft 80M loaded mobile whip to something far longer
can have a large net improvement over the high losses of short
(under 10ft) antennas.   One of the arrangements I have is a base
fed inverted L 24ft tall and length as needed to tune for 80M.
Counterpoise is two 65ft wires on the ground.  That with match
box at the base worked very well compared to many things.

If all else fails I have a small plastic bag with wire and transformer
to make a grasswire and if deployed a few inches or a foot off the
ground has worked well (way better than nothing!) on 75 and 160.

Allison
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WB6BYU

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Re: Portable Antennas
« Reply #8 on: October 21, 2021, 11:48:36 AM »

One additional rule I would add to my prior list is:

3) make it adaptable

Sometimes you know exactly where you will set up, and what
supports are available.  Sometimes you can carry a lot of
different options to cover any eventuality.  But there may be
occasions when you have no idea where you will be setting
up, or what you might need - like a backpacking trip in a new
area, where you are limited on what you can carry.

While I refer to my antenna as a "dipole kit", it is simply wires
that I can attach to a center feedpoint in any combination
when I go to set it up.  Might be multiband, especially if I am
going to be at a spot for a day.  Might be a single band, when
I'm stopped for lunch, or don't have space for anything longer.
Or I might combine the wires different ways, such as using a
quarter wave 40m wire as a full wave loop on 10m, or using
some of the wires to make a parallel feedline or a vee beam.

I generally rely on trees, rather than carrying a mast, but
sometimes I have had to improvise - hanging the antenna
from a fence post or a pile or gravel, or propping it up with
my walking stick a few feet high.  At least twice we have run
80m dipoles along hedges beside a parking lot.


There are lots of versions of "portable operation", from what
I can carry in a backpack for a week, to what a squad of
Marines can haul in a 2 1/2 ton truck and set up in a day
without needing to pour a concrete foundation.  Your choice
will depend on where you expect to set up, how many helpers
you have, available supports, limitations on what you can do,
power level, who and where you want to talk to, etc.  Don't
assume anyone else's "best portable antenna" is necessarily
right for your application.  (Not even my suggestions!)

Every setup has trade-offs to make.  I find that antenna
efficiency is more important with QRP, for example, than
when running higher power.  Vertical antenna performance
varies with the ground conductivity where you will be operating:
what works well in the mid-West might not work as well in
the Southwest where conductivity tends to be poorer.  Operating
from a vehicle in a parking lot may require more consideration
of others than a remote site in the wilderness.  The size of
your vehicle may determine what antennas are practical to
carry (I can only fit my TA33jr elements in my van if they
stick out the passenger window, which leads to issues with
rain and security).

A lot of the antennas mentioned here are relatively cheap - you
might want to take several with you (when you have a chance)
and compare them to see what works best for your specific
circumstances.  Because in the end, that will be a more
accurate assessment than listening to a bunch of us babble on
about what we like for our style of operating, if it doesn't
apply to what you plan to do.

K3XR

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Re: Portable Antennas
« Reply #9 on: October 21, 2021, 12:09:41 PM »

I posted this in "Portable Operations"...maybe I should have posted it here.

Just returned from a weeks camping in one of the Pa state parks where I do most of my camping 4-5 weeks every year.

My set-up for portable operation is as follows.
Spiderbeam 40 ft. HD push up fiberglass mast. (attached to spare tire mount )
ULTIMAX DXTREME  33 ft end fed antenna attached to the mast
two 33ft counterpoise wires
Kenwood TS-480S
Computer for digital modes with a USB GPS receiver for accurate time.

I have used a number of different antennas over the years and have settled on this arrangement as my preferred portable antenna.  Using the antenna tuner in the Kenwood it performs very well on 40-6 meters.  Last time out doing just casual operation worked about 60 stations on a number of different voice, cw and digital modes.
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KL7CW

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Re: Portable Antennas
« Reply #10 on: October 21, 2021, 12:23:00 PM »

Prior to about 1990 nearly all of my CW QRP operation, typically with about 2 watts, on hiking trips, extended bicycle expeditions used linked dipoles set up as inverted V's since I usually traveled where there were trees, but it even worked marginally with the dipole laying on the bushes, a canoe paddle, sky/hiking pole, etc.  The performance was good, but set up was a pain in the xxx and after a long day often I did not want to bother with the ham radio thing.
     Fast forward to about 16 years ago when I got my Elecraft KX-1 with a built in tuner.  On most trips ham radio was not my primary objective since we were visiting grand kids and relatives in Norway, England, and several US states.  I rarely carried my nifty linked dipoles and just used a 26 foot wire more or less vertical, draped over a branch, or whatever.  My usual power was about 1.5 watts with the internal batteries.  Usually I just laid one or two 17 foot wires on the ground.  Made many hundreds of fine QSO's on 40, 30, and 20 meters.  If I was in a park, often just used the metal picnic table with or without other wires laying underneath if there was pedestrian traffic.  Even worked across the Atlantic in each direction, but do not count on this !  Sometime I used an elevated counterpoise laying on the bushes or a deck.  Sometimes it would load, but sometimes a resonant or near resonate counterpoise was required.
      For sure this is a significantly compromised antenna with probably something like an S unit inferior to an inverted V with the apex at say 20 to 35 feet.  For field day, or an extended ham trip, a better antenna is well worth the perhaps hour of set up time.  Many of my very successful operations were over 5 years ago when propagation was much better.  In recent years operation from remote places like Montana, Arizona, Alaska, etc. were not successful so a better antenna and more power than my QRP/QRPP rigs might have made a difference.  I even bought a KX-2 so I could gain a few more dB when needed.
      After covid when we travel again, will probably stay with my 26 foot wire antenna, since visiting family and friends trumps ham radio activities (usually !).
      This is what I used for CW, but am 100 % certain the results with the simple wire would not have been very good on SSB or AM.             Cheers,  KL7CW
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KL7CW

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Re: Portable Antennas
« Reply #11 on: October 21, 2021, 01:26:54 PM »

In the next few years propagation should be better on 17 and 15 meters at times than on 20 meters and lower frequencies.  For example when propagation was better years ago, I had a 15 meter CW rig which only put out about one watt.  I made many good 2000 mile plus contacts which were easier and much better than QSO's on 20 and 30 meters when I ran about 4 or 5 watts.  I know this is not a good scientific comparison, but believe that when (if) propagation improves the higher HF bands may be a good choice, especially for QRP operators with compromise antennas.  Part of the advantage may be that there are fewer competitive high power operators, especially on the WARC bands. Make sure you are set up for the "bread and butter" bands of 20 and 40 meters, but if possible be ready to jump up to 17 meters (or higher frequencies) when (if) they open up.  Not long ago I even had a good SSB QSO with 5 watts and a ham in the lower 48.         Rick  KL7CW
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KD2TTM

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Re: Best portable antenna
« Reply #12 on: October 21, 2021, 06:34:29 PM »

I have a SOTAbeams linked dipole and one of their masts to go with it.  Setting it up as an inverted V  requires extending the mast, staking out one guy line and the two antenna ends.  Sometimes I have to fidget with the antenna end locations but not always.  I estimate the set-up time at around ten minutes.

My favorite portable antenna is also the easiest to set up and use.  It's a Par EndFedz 10/20/40MkII end fed half-wave.  To set it up as a sloper, I throw a line over a 20'-30' high tree branch, haul up the antenna, then stake out the feed end with a tent stake.  Done and ready to go in about the same ten minutes.   I've made plenty of DX contacts with it and my 20w Xiegu G90, some in excess of 4K miles.

If it took me an hour to set up my portable antenna, I don't think I'd use my portable stuff very often at all....
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K2WPM

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Re: Best portable antenna
« Reply #13 on: October 25, 2021, 04:33:31 AM »

AE0Q - Great ideas. 
I used the push-up pole set-up also, with the linked vee.  Lash it to a fence or whatever.
Worked well for me, but I still waste enormous amounts of time setting up and breaking down the set-up.

WB6BYU - excellent ideas, especially to analyze each step and find out why it takes so long:

1.  Open up the pole - I put painter's tape on each junction.  Install a carabiner at the top to act as a pulley so I can raise and lower the antenna to change bands.  Unsnarl the string and raise the pole, lash it.  15 - 20 minutes.
2.  I don't use the pole anymore, I shoot a string over a high branch ... hopefully 50 feet or more -- using Long John pole-sling shot.  Tie it off and hoist the antenna.  still 15 - 20 minutes.
3.  Assemble the linked dipole.  I store each band's elements in plastic baggies labelled for the band.  Center feedpoint and 20 meters is one bag.  40 meters is next bag.  75 meters is a bag.  Finally, I've never seen this done, but I also have bag for 80 meters ... short five-foot segments that allow me to do CW band.  Since I usually operate 20-40-75 meters (in that order). I connect those segments, using insulated carabiners pre-attached to the respective segments in the baggies.  15 - 20 minutes.
4.  Pull out 75 feet of coax, unsnarl it and attach to feedpoint, hoist antenna.  10 minutes.
5.  Take string, unsnarl it (have to try that figure-of-eight trick) and and attach 25 - 50 foot on each end of the antenna, find a suitable tree to tie it off so vee ends are well above ground level.  15 - 20 minutes.
6.  Check antenna with my Rig Expert AA-170.  One advantage of the linked vee is being able to get under 1.5 SWR, and therefore not need external tuner on various bands, connect coax to rig and power up the rig.  5 minutes

KD2TTM

Rob, I think that may be my solution, just go with EFHW, in my case 125 feet, for 80-40-20, set up as a vee.  (Only one piece of string to snarl).  I have a homebrew 49:1 balun, so that's good.  I used a 66 foot EFHW in vee with fiberglass pole and got good results on 20 and 40.  (P.S.,  I still have Prospect Mountain on my bucket list, Rob.)

KB1GMX

Good ideas, thanks.
I thought you were kidding about the "grasswire" antenna.'
Till I googled it.  Wow.

K0UA

I'm gonna try that with my Dodge Dakota!

VK3YE
Peter, what a privilege, thanks for taking the time.
For those who haven't checked, Peter is a prolific Youtuber (great videos!) and author ... in most cases portable and portable-related topics.  But be careful, if you go to his Tube page, you may stay there for a while.  Same with the web page ...

N2TO
Thanks Kevin, what's your best antenna?  Answer: your next antenna.
I really like the carbiners; I insulated them using shrink wrap.







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KD2TTM

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Re: Best portable antenna
« Reply #14 on: October 25, 2021, 04:53:42 AM »

AE0Q - Great ideas. 
KD2TTM

Rob, I think that may be my solution, just go with EFHW, in my case 125 feet, for 80-40-20, set up as a vee.  (Only one piece of string to snarl).  I have a homebrew 49:1 balun, so that's good.  I used a 66 foot EFHW in vee with fiberglass pole and got good results on 20 and 40.  (P.S.,  I still have Prospect Mountain on my bucket list, Rob.)


I was very, very happy with my SOTAbeams linked dipole until I tried the EndFedz EFHW... comparable performance and couldn't-be-easier band switching; no more taking down the antenna to connect or disconnect segments.  I must admit that I've never tried it in an inverted-V configuration... I should do that to get a better comparison to the SOTAbeams antenna.

The views from Prospect Mt. are nice, David, and the Lake George area in general is a pretty place.  Come on up and have a look around!
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