dipole antenna efficiency

[Don Wilhelm-4]

Chris,

I respectfully disagree.  A good current balun or a balanced tuner will
cure any common mode noise that may be present on the feedline.

Of course the real 'secret' is to run the feedline away from the antenna
at a 90 degree angle and support the feedline away from conducting
surfaces - if done properly, common mode pickup will not be a problem.

73,
Don W3FPR

Chris Kantarjiev wrote:

> The *problem* with ladder line fed antennas is that it's very
> difficult to remove common mode noise from them. If that's
> not an issue for you ... fine. But if it is...
>
> 73 de chris K6DBG
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[David Cutter]

Here is an interesting antenna made by Lloyd Butler VK5BR.  It uses open
wire feeder to a VERY small antenna.

http://users.tpg.com.au/users/ldbutler/ReverseFeedTopLoading.htm

David
G3UNA

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[N2EY]

In a message dated 1/4/08 4:34:29 PM Eastern Standard Time, [hidden email]
writes:


> I've never understood the popularity of the G5RV.  It's
> achieved a sort of "cult" following.

It's an ingenious compromise antenna for several bands, that's all.
Actually, just a ~102 foot dipole with a matching system that gives
"low" (but not unity!) SWR on several HF bands, so that a simple
ATU can match it.

  The original design
>
> was for a 20M -ONLY- antenna,

Not true!

I have PDF's of the original articles by G5RV himself, and from the very
beginning it was a multiband design. He had a small garden ("back yard" to us
Yanks) and wanted to get on the air easily, quickly and simply. For his
application, it worked.

But it must be remembered that when G5RV designed the antenna, the ham bands
were somewhat different than today. 30, 17 and 12 meters weren't ham bands at
all. 9-/75 meters in G land was 3.5 to 3.8 MHz only, and 40 meters was 7.0 to
7.1 MHz.

Most important of all, the rigs in use were capable of matching "reasonable
levels of SWR" - meaning 3 or 4 to 1 wasn't considered to be worth worrying
about for the bands and short lines being run.  

and somehow has
>
> morphed into a do everything hoax.

Not a hoax, but there's a lot of misunderstanding about the antenna.

The biggest misunderstanding is that too many folks expect to put up a
G5RV-like antenna and get 1:1 SWR on all parts of every HF band from 80 thru 10
meters, automatically. And work the world with the same ease as folks with big
aluminum.

That's just not going to happen. It's just a dipole with an ingenious feed
system, not magic.

> I do antenna talks at conventions and hamfests, and
> I always ask; "How many of you use a G5RV"? The
> hands go up and it's usually about 50% of the audience.
> I say; "Gosh, I'm sorry", and try to show them how much
> easier and more efficient it would be to simply use the
> open wire feeder portion of the antenna and a balun at/in
> the (required) tuner.
>

It's easier to do it that way *IF* you can make the feedline and antenna
length such that the balun doesn't have to deal with very high, very low, or
highly reactive impedances on the bands of interest. Or if you can run the balanced
line all the way to a true balanced tuner that can handle the impedances
presented to it.

> Some years ago the "Carolina Windom" had the same
> sort of following....
>

And for the same reasons - with the same limitations.

The G5RV and Windom antennas can be useful solutions in many cases. The main
thing is to understand how they work and what their limitations are.

---

Comparing HF antennas can be very misleading because of all the vagaries of
propagation and expectations. For example, suppose two hams with identical 100W
output rigs put up identical dipoles, but Ham A's dipole has a feedline/tuner
system that is 88% efficient and Ham B's dipole has a feedline/tuner system
that is 22% efficient.  

Ham A loses only 12 watts in the feedline/tuner system - that's about as good
as it gets on HF. Ham B loses *78* watts in the feedline/tuner system -
almost six times the loss of Ham A!

Yet at the receiving end, the difference is only one S unit - 6 dB. Slight
differences in propagation could easily mask that and make Ham B's antenna
appear to be as good or better than Ham A's.

A lot of hams will say a particular antenna "works great" for them. But what
does that really mean? I remember one multitransmitter Field Day, some years
ago, when a variety of antennas were tried out by the various station teams.
All reported their setups "worked great" when notes were compared a few hours
into the contest.

But for one team, that meant they were able to average 40-60 QSOs/hour, and
for another team, it meant 10-15 QSOs/hour!  Their expectations were completely
different. (And compared to truly competitive setups, neither was a
world-beater).

73 de Jim, N2EY


**************
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shape.
     
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[N2EY]

In a message dated 1/4/08 4:31:49 PM Eastern Standard Time, [hidden email]
writes:


> The most expensive thing is ground to install
> them where antenna restrictions don't bring down the
> wrath of the taste police.

AMEN!!

(I have been trying for
>
> over 50 years to convince the world that antennas are
> beautiful, but without success)

Me too.

I've always found it odd that the very people who want the convenience of
modern technologies often consider the technologies themselves to be
unattractive, and want things to look like a time when life was much more difficult.

73 de Jim, N2EY


**************
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shape.
     
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[David Cutter]

Ooops.  I must apologise for my mistake:  I've read the article in more
detail and Lloyd is not feeding a small antenna, he is using the "feeder" as
the antenna by deliberately unbalancing it with a terminal unit to obtain
maximum current at the far end of the feeder.  Presumably this would then be
elevated to a convenient point for maximum effect.

David
G3UNA

> Here is an interesting antenna made by Lloyd Butler VK5BR.  It uses open
> wire feeder to a VERY small antenna.
>
> http://users.tpg.com.au/users/ldbutler/ReverseFeedTopLoading.htm
>
> David
> G3UNA
>
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[Kurt Pawlikowski]

David,

    Actually, if you follow some of the other related articles Lloyd
wrote, the effect of this design seems to approximate a full wave dipole
with a device about 2% of a wave length. That is, a 40 meter antenna
about 3 feel long. He also purports a kind of "folded" antenna for 80
meters at about the same length. Wow. The possibility of a 6 foot long
160 meter antenna that works. I am definitely intrigued!

    Regards,

    kurtt

    Kurt Pawlikowski, AKA WB9FMC
    The Pinrod Corporation
    [hidden email]
    [phone]
    http://pinrod.com

David Cutter wrote:

> Ooops.  I must apologise for my mistake:  I've read the article in
> more detail and Lloyd is not feeding a small antenna, he is using the
> "feeder" as the antenna by deliberately unbalancing it with a terminal
> unit to obtain maximum current at the far end of the feeder.  
> Presumably this would then be elevated to a convenient point for
> maximum effect.
>
> David
> G3UNA
>
>> Here is an interesting antenna made by Lloyd Butler VK5BR.  It uses
>> open wire feeder to a VERY small antenna.
>>
>> http://users.tpg.com.au/users/ldbutler/ReverseFeedTopLoading.htm
>>
>> David
>> G3UNA
>>
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[AC7AC]

CONTENTS DELETED

The author has deleted this message.

[dave.wilburn]

Absolutely.  Even when you look at Joe's site, www.k1jek.com there is
enough info in what you see to make the antenna.  Rotor cable, ladder
line, a balun and coax.  I personally do not think what he asks for the
on the website is overly much.  He makes the products himself, and
stands behind them.  He actually answers the phone when you call and ask
questions.  My life is a bit complicated, but I could have easily made
one.  I was willing to make the trade of money vs. time and materials.

As an example, I had a quick QSO with AA4AK the other night, so I could
have Maine for WAS LOTW.  I found out the next morning, after finishing
my DL1 and going to play with it, that the rig was set to 8w.  The
antenna must be doing something right.
-  

David Wilburn
[hidden email]
K4DGW
K2 S/N 5982


On Fri, 2008-01-04 at 18:11 -0500, Thom LaCosta wrote:

> On Fri, 4 Jan 2008, David Wilburn wrote:
>
> > I understand many G5RV's are getting replaced with these antennas.  I
> > have the Grampy version, that is 100' long on each side, for a total of
> > 300' of wire on each side, all in a 100' on each side package.  Have had
> > good luck with it.  Their shortest is a bit over 70'.
>
> And should you want to roll your own:
>
> http://www.hamuniverse.com/cobraantenna.html
>
> Thom,EIEIO
> Email, Internet, Electronic Information Officer
>
> www.baltimorehon.com/                    Home of the Baltimore Lexicon
> www.tlchost.net/hosting/                 Web Hosting as low as 3.49/month

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[w7aqk]

----- Original Message -----
From: <[hidden email]>
To: <[hidden email]>; <[hidden email]>
Sent: Saturday, January 05, 2008 7:28 AM
Subject: Re: [Elecraft] dipole antenna efficiency

> In a message dated 1/4/08 4:34:29 PM Eastern Standard Time,
> [hidden email]
> writes:
>
>
>> I've never understood the popularity of the G5RV.  It's
>> achieved a sort of "cult" following.
>
> It's an ingenious compromise antenna for several bands, that's all.
> Actually, just a ~102 foot dipole with a matching system that gives
> "low" (but not unity!) SWR on several HF bands, so that a simple
> ATU can match it.
>

Well, it depends on what your definition of "low" is.  The SWR is below 2:1
on only 1 band--20 meters.  On others it goes to 5:1 or more on most of the
non-WARC bands, and is almost unusable on 30  and 17 meters.  That is,
unless you use a tuner!  Use of a tuner is really the big bone of contention
usually.  This antenna has been described as not requiring a tuner, when it
really does need one for the most part.  Even Varney anticipated that as he
has discussed in several articles.

Another problem is that, although Varney described his antenna sufficiently,
so many variations have been born (but still are called "G5RV's"), in an
attempt to improve the SWR on one band or another, that the "real G5RV"
isn't even described that much anymore.  SWR can be improved on various
bands, but usually at the expense of the SWR on another band.  Cebik
describes a pretty good variation on his website.  As I understand it,
Varney's objective was primarily to add 20 meters to an antenna that would
also load acceptably on 80.  But he never intended for this to be a
"tunerless" antenna from 80 through 10 meters.

Dave W7AQK



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[John Magliacane]

When it comes to antenna efficiency, it is important to understand
that when RF energy is applied to any antenna, three things will
invariably happen:

a) The antenna will convert a portion of the applied AC voltage
and current into electromagnetic energy and radiate it into space.

b) The antenna will convert a portion of the applied AC voltage
and current into heat energy as a result of resistive losses in the
antenna structure.

c) The antenna will reflect a portion of the applied AC voltage and
current back to the transmitter as a result of an impedance mismatch
between the antenna and that of the source.

Unless steel or nichrome wire is used, or electrically poor
connections exist in the antenna structure, losses due to (b)
will be low.

Effects of (c) can be reduced or eliminated by using intelligent,
low-loss impedance matching techniques and low-loss feedline.
(Technically, reflected power isn't a "loss" per se, since
energy isn't dissipated when a reflection occurs.)

That leaves us with (a), the desired outcome of applying RF energy to
an antenna.  Since losses due to (b) and (c) are typically low and/or
easily corrected, it is very difficult NOT to achieve high antenna
system efficiency.

Shortening the physical length of an antenna below that of a
half-wavelength DOES NOT reduce its efficiency provided the
necessary efforts to minimize resistive losses in the antenna
structure and the impedance matching networks are made.

That last statement is so important and so often misunderstood,
it bears repeating:

Shortening the physical length of an antenna below that of a
half-wavelength DOES NOT reduce its efficiency provided the
necessary efforts to minimize resistive losses in the antenna
structure and the impedance matching networks are made.

We could make an 80-meter dipole just one foot long and realize
high efficiency if the proper low-loss impedance matching techniques
are employed.

If we were to apply 100 watts to such an antenna, and we get zero
watts reflected back, and the antenna and matching networks remain
cool, then 100 watts of RF energy is being radiated from that one
foot dipole -- the same as if a full-sized dipole were used.

The penalties for using physically shortened antennas are:

(a) Decreased operating bandwidth
(b) Decreased directivity
(c) Somewhat difficult impedance matching

If we're wiling to adjust our impedance matching networks when we
QSY, then (a) isn't much of a problem since our signals are seldom
more than a few kHz wide, anyway.

Dipoles have 2.14 dB "gain" over isotropic radiators.  As we make
our dipole shorter and shorter (and keep resonating and impedance
matching it in the process), its directivity (b) approaches that
of an isotropic radiator.  If our radiating structure and impedance
matching networks are lossless, an extremely short dipole may be as
much as 2 dB weaker than the signal produced by a half-wave dipole
in the broadside direction.  That's less than half an S-unit!

So, the key to success lies in (c), the impedance matching network.
It needs to have extremely low loss, be capable of matching a very
wide range of impedances, and (unless you're rock-bound) be agile
so the antenna can be operated across a broad range of frequencies.
Ideally, it should be placed at the antenna feedpoint, itself.


73, de John, KD2BD


Visit John on the Web at:

        http://kd2bd.ham.org/
.
.
.
.


      ____________________________________________________________________________________
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[Kurt Pawlikowski]

David,

    Actually, if you follow some of the other related articles Lloyd
wrote, the effect of this design seems to approximate a full wave dipole
with a device about 2% of a wave length. That is, a 40 meter antenna
about 3 feel long. He also purports a kind of "folded" antenna for 80
meters at about the same length. Wow. The possibility of a 6 foot long
160 meter antenna that works. I am definitely intrigued!

    Regards,

    kurtt

    Kurt Pawlikowski, AKA WB9FMC
    The Pinrod Corporation
    [hidden email]
    [phone]
    http://pinrod.com

David Cutter wrote:

> Ooops.  I must apologise for my mistake:  I've read the article in
> more detail and Lloyd is not feeding a small antenna, he is using the
> "feeder" as the antenna by deliberately unbalancing it with a terminal
> unit to obtain maximum current at the far end of the feeder.  
> Presumably this would then be elevated to a convenient point for
> maximum effect.
>
> David
> G3UNA
>
>> Here is an interesting antenna made by Lloyd Butler VK5BR.  It uses
>> open wire feeder to a VERY small antenna.
>>
>> http://users.tpg.com.au/users/ldbutler/ReverseFeedTopLoading.htm
>>
>> David
>> G3UNA
>>
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>

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[WILLIS COOKE]

This thread started with a person trying to find an
antenna that would work reasonably well that does not
take up much space.  While in theory, you are correct
the practical aspects of making a very small antenna
for low frequencies lead to impossible parameters.
The radiation resistance of a dipole 2 meters long for
3.8 mHz is about 0.134 ohms.  Since placing such an
antenna in free space would require the assistance of
NASA we need to assume that it is a bit lower.  If we
assume that the person cannot or does not want to
erect a tall mast, probably a height of about 3 meters
would be reasonable to expect.  This would make for a
radiation resistance of about 0.006 ohms and need.
The capacitive reactance will require 397 microhenrys
to cancel out which in turn will require a coil 4
inches in diameter and about 24 inches long with 160
turns (about 168 feet of wire).  Then you would need
an 8333/1 balun transformer with its associated wire
resistance.  Clearly not a very practical way to make
an antenna that would radiate straight up and would
have a bandwidth less than required for a single
sideband signal.  Now if you have theoretical
inductors and capacitors and  no resistance wire
available to you, maybe you can do better.
(Calculations by EZNEC)

A more practical solution for a ham that cannot afford
or is prohibited from putting up a large antenna is a
mobile antenna attached to a porch rail or rain gutter
or whatever metal that is available.  Better is the
common trap vertical.  If a person has a bit of space
and can erect a 30 or 40 foot mast all sort of
possibilities present themselves.

This has certainly been an interesting thread and can
go on forever if we choose.  Hams have been designing,
trying and debating antenna designs since Marconi
started it all and I don't think it will end soon.

73 to all, Cookie, K5EWJ

   
--- John Magliacane <[hidden email]> wrote:

> When it comes to antenna efficiency, it is important
> to understand
> that when RF energy is applied to any antenna, three
> things will
> invariably happen:

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[AC7AC]

CONTENTS DELETED

The author has deleted this message.

[David Woolley (E.L)]

John Magliacane wrote:
> When it comes to antenna efficiency, it is important to understand
> that when RF energy is applied to any antenna, three things will
> invariably happen:

For antennas in practical locations, at least one other thing will happen:

d) The antenna will convert part of the AC power into (near field)
electromagnetic energy which will induce currents in the ground,
building structure, wiring, water and gas pipes, etc.  Much of that
energy will be converted to heat after it has lost, although some will
be re-radiated (I believe, in extreme cases, if the current is induced
in something large enough and resonant, the re-radiator can become the
actual antenna and the antenna act as a feed device, but, normally, for
low, and indoor antennas, this is where most of the energy turns to heat).

Normally, even without losses, induced currents in the ground below a,
low, horizontal dipole will tend to cancel the far field signal,
resulting in less power actually being radiated, and a lower radiation
resistance, requiring even lower losses in all components from antenna
wire back to and including the ATU.

(One way of considering the far field is that you need to create a
relatively large electric or magnetic field far enough from the antenna
that its phase lags that close to the antenna by a significant amount.)

> c) The antenna will reflect a portion of the applied AC voltage and
> current back to the transmitter as a result of an impedance mismatch
> between the antenna and that of the source.

This reflection abstraction causes a lot of confusion.  It is possibly
easier to see it as simply a bad match between the transmitter source
impedance (which is usually rather different from the optimum load
impedance) and the antenna impedance, causing most of the DC input to
the transmitter to end up as heat in the output devices.

>
> Unless steel or nichrome wire is used, or electrically poor
> connections exist in the antenna structure, losses due to (b)
> will be low.

As already pointed out, skin effect means that this is not true.  People
experimenting with small magnetic loops have to use large copper pipes
to keep ohmic losses manageable.  (In some cases I suspect they are
still high compared to radiation resistance, but lower than the near
field loss resistance.)

> Effects of (c) can be reduced or eliminated by using intelligent,
> low-loss impedance matching techniques and low-loss feedline.
> (Technically, reflected power isn't a "loss" per se, since
> energy isn't dissipated when a reflection occurs.)

Note that devices capable of doing this for the sort of antenna being
considered in this thread are not easy to find, if they can be found at
all.  For example, the KAT2 has a 10:1 SWR matching specification, but
matching the antenna discussed here, at infinite height above the
ground, needs a 250:1 range, or more.  They can also have power losses.

> That leaves us with (a), the desired outcome of applying RF energy to
> an antenna.  Since losses due to (b) and (c) are typically low and/or
> easily corrected, it is very difficult NOT to achieve high antenna
> system efficiency.

(b) and (c) are not typically low for the sort of antenna considered
here, although (c) isn't really achievable, anyway.

>
> Shortening the physical length of an antenna below that of a
> half-wavelength DOES NOT reduce its efficiency provided the
> necessary efforts to minimize resistive losses in the antenna
> structure and the impedance matching networks are made.

But, apart from possibly cooling everything to near absolute zero, they
cannot be made.

>
> That last statement is so important and so often misunderstood,
> it bears repeating:

I'd agree that there is a misunderstanding that is common.  It arises
because people have difficulty with the idea that an antenna can have a
capture area that is a lot bigger than the antenna, and because people
don't understand that the real limitation on small antennas is power
losses.  Large antennas have gains that equate to directivity, and
people try to extrapolate these down to small antennas, whereas there
are no Maxwellian reasons why a small antenna cannot be efficient, only
materials science, engineering and environmental ones.
>
> If we were to apply 100 watts to such an antenna, and we get zero
> watts reflected back, and the antenna and matching networks remain
> cool, then 100 watts of RF energy is being radiated from that one
> foot dipole -- the same as if a full-sized dipole were used.

Radiation is normally used to refer to far field radiation, which is the
only radiation useful for normal ham radio communications.  The antenna
can remain cool even if all the power is going into heating up the
ground, or the re-inforcing bars in your concrete building.

>
> The penalties for using physically shortened antennas are:
>
> (a) Decreased operating bandwidth

I'm not sure that is inevitably true.  My reference for normal mode
helices included them in the section on broadband antennas.

> (b) Decreased directivity

Directivity ceases to be a factor much below a half wave, and I don't
think that there is much difference between a halfwave dipole and a stub
dipole in free space.

> Dipoles have 2.14 dB "gain" over isotropic radiators.  As we make
> our dipole shorter and shorter (and keep resonating and impedance
> matching it in the process), its directivity (b) approaches that
> of an isotropic radiator.  If our radiating structure and impedance

Although I cannot find an exact formula at the moment, the gain will not
be asymptotic to 0dBi, but will, rather, not be too different from 0dBd.
  Incidentally, I have a feeling that the 2.14dBi applies to an
idealized short dipole, rather than a half wave one.

All in all, then, Maxwell doesn't prohibit high efficiencies from very
small antennas, but engineering practicalities do.

--
David Woolley
Emails are not formal business letters, whatever businesses may want.
RFC1855 says there should be an address here, but, in a world of spam,
that is no longer good advice, as archive address hiding may not work.
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[bill KE5KWE]

Let me bring this down to the practical world.  My QTH is a 42.5 ft. Travel Trailer which is insulated from the ground by 6 Rubber Tires and Air.  It has Metal, I presume Aluminum, siding and a Rubber over Wood Roof which is approx. 10 ft. off the ground.  My K2 is almost built and I will be operating CW exclusively QRP.  Are there any suggestions for either a commercially built antenna or a homebrew. (Recognizing that I am not a EE and have no formal electrical background!)

Thanks

Bill Fogel, KE5KWE
"On the Road in the USA"

<quote author="pappy_c">
This thread started with a person trying to find an
antenna that would work reasonably well that does not
take up much space.

[Ken Kopp]

Bill,

My Lady and I are serious half-time RV'ers and I've had
very good results with my K2 into a modified High Sierra
screwdriver on a 5th-wheel Holiday Rambler.

I'll send you photos.  It's also pictured on K0BG's mobile
site.

73! Ken Kopp - K0PP
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or
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[ARDUJENSKI]

Interesting discussion. I have a question  regarding this topic I hope the
more learned in the group cans help clarify.  Although efficiency is important
is determining an antenna selection, is antenna  lobe pattern just as
important? If the lobe pattern did not allow you to say  work DX or to work a
particular direction then is efficiency all that important?  Should we look at the
desired pattern for a particular operating goal then  consider the antenna
efficiency?

Alan KB7MBI
Woodinville, WA
FISTS:  5702   CC: 1885   ARS: 582
SKCC: 1988   NAQCC:  058   ARCI: 12141  




**************Start the year off right.  Easy ways to stay in shape.    
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[IK4YNG]

 

Hi Bill,
I second in full what Ron told you. I would like to add my "two cents" of
personal experience...

Building an Elecraft K2 was a good choice. I have one too, together with
countless other radios; the difference is that the K2 stays, the other
radios have been sold. It is a very nice rig, with outstanding performances.


Working QRP CW is a good idea as well. If you manage to put up a decent
antenna, you will be able to work *any* station that you will hear, with
only one exception: those stations located in a very noisy, urban
environment where the s-meter reads noise at S8 all across the whole band,
and you need S9 to be heard. But believe me, 97% of Earth's surface is not
so noisy, and DX locations are usually the quietest.

Last, I strongly advice you to include the internal ATU option in your K2.
Believe me, it is worth every cent of his cost and it is optimized for
mobile installations.

A screwdriver antenna can be a good choice, but I have another idea. Most
probably you will not be able to operate while driving, especially on CW, so
the most important factor will be to have a good and efficient antenna while
parked.
Take a look here:
http://www.iv3sbe.webfundis.net/html/Rybakov806.htm

I have personally used this antenna, and still I use it. It is made of a 9
meters long fishing rod (about 24') with a toroidal transformer at the base.
It can be purchased online, but I'll suggest you to make one yourself; the
toroid can be found online (Google Amidon Associates or Palomar Engineers)
and the length of the fishing rod is not critical. The internal ATU of your
K2 will match this antenna in a breeze.

Upon arriving at your selected location, you just whip the fishrod/antenna
to her full length, tape a thin wire along it, and fix the base to any
suitable post (you can fix one permanently on a corner of your vehicle).
Then spread a few radials around; any length will do; just one will work,
but a few radials at least one quarter wave long will work WAY better. Just
have a look at your SWR and prune those radials for best matching (place an
external, inexpensive SWR meter between the K" and the antenna for that). It
must be done only once.

For those lucky days when there is a nice tree around, you will just connect
a longer wire to the toroid and launch it up in the tree. If you have two
trees, you can make an inverted L; and sometimes you will be able to make a
homebuilt G5RV: anybody capable to build a K2 will build a G5RV in an
afternoon, and the cost can be virtually nil. Look here:
http://www.eham.net/forums/Elmers/2156 for advices.

Now, the "fish rod" vertical antenna will be very good for DX (low radiation
angle, good efficiency) while the G5RV will be good for low bands and NVIS
connections (I mean, within 350 miles or so in low bands). And believe me,
you will enjoy your rig and your antennas MUCH MORE than some monsters...
Look here for the biggest I've seen: http://www.kkn.net/dayton2006/K9LTN.pdf


By the way, I also own an Elecraft KX-1 with the internal ATU. The size of a
cigar box including batteries, 24' of wire as an antenna. I carry it in my
backpack. I worked all of Europe from an Italian hill in a single afternoon
with it. With CW, power is NOT a factor.

Finally, you will enjoy the results of your own good work. Not being a
technician is not an excuse; ask Guglielmo Marconi for that!

Cheers (and 73)
IK4YNG Paolo


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