Re: [Elecraft] [OT] end-fed halfwave antennas

[Gil via Elecraft]

Hello,

I wouldn't bother with a J-Pole type antenna for HF. The only one I made
remotely close was a Slim Jim for 6m, with ladder line. It worked well.
Making an UNUN for an end-fed is much simpler. All it takes is one
toroid and one capacitor if you want it to be adjustable.

My favorite portable antenna now is a 9:1 EARCHI UNUN, a 19ft wire and a
6m fishing pole. It's not a half wave but it works well down to 40m. If
I can find a tree then I throw a half wave wire and tune it with my
Ilertenna end-fed tuner. There is only one "tie-up" point, very
practical and gives me a low radiation take-off angle.

Except for 80m I'm done with horizontal antennas, especially in the
field. It's just too hard to get them high enough and the results are
never as good as an EFHW.

The only instance I would use a counterpoise wire with an EFHW is if my
coax cable (RG-174) is shorter than 25ft. Otherwise it doesn't make any
difference that I can tell.

Gil.

a...@sbcglobal.net wrote:
> I know the J-pole is pretty effective for VHF and would think for HF
> also?   If the quarter wave matching stub were somewhat shorter, I was
> thinking the difference could be made up by an inductor or coil at the
> near end?   A secondary link coil approximately equal to the impedance
> of the coax feed line should effectively couple the RF to the stub and
> EFHW wire?   Some value of inductance coupling should be ideal for a
> good match between coax line and the 1/4 wave matching stub.
-- 
Development, Unix servers, Databases.
PGP Key: http://keskydee.com/gil.asc
If mail bounces try gil...@yahoo.com

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Re: [Elecraft] [OT] end-fed halfwave antennas

[Nr4c]

Not again?

Sent from my iPhone
...nr4c. bill


> On Feb 14, 2017, at 11:48 AM, Guy Olinger K2AV  wrote:
> 
> In spite of ON4UN's 4.3, I stand by my prior statements concerning the
> excellence of end-fed half wave antennas (EFHW), and their non-existent
> requirements for vast counterpoise. In that specific regard, ON4UN is
> unfortunately off the mark. More on that below.
> 
> Those of you using the becoming popular (?) EFHW portable antennas with
> your excellent Elecraft portable rigs, you do NOT need to worry about
> putting down a dense 0.35 wavelength radial field for them to work very
> nicely.
> 
> I've had 50 plus years experience with 80m EFHW antennas, particularly the
> EFHW inverted L or EFHWL. I, and all those I have helped install one to
> improve their signal, have had very successful experience with EFHW aerial
> wires. It's long-term lack of general popularity among hams has always been
> curious to me. I personally attribute that to the lack of a robust
> commercial **remote** tuner **made for the purpose** to go at the base. An
> off-the-shelf version has always been needed to serve hams who for whatever
> reason are unable or disinclined to construct these devices for themselves.
> 
> None of this 50+ years of excellent EFHW experience included a 0.35
> wavelength radial field. They all included very minimalist counterpoise,
> including maybe one hand's worth fed against a ground rod. I remember one
> just outside a window and within a few feet of the property line. I never
> recommended a ground rod, but I must admit that those worked tremendously
> better than what they were previously using. And it was their house, not
> mine. Who knows what kind of blowback they were getting about antennas.
> Back then radio could put lines through TV signals and create next door
> enemies.
> 
> I will further add that an 80 meter end-fed halfwave L, and against very
> minimalist ground or counterpoise, is arguably the **best** single wire
> 80/75m antenna for **both** DX and local contacts, and as such a real
> winner for small lot situations. Especially for those small lotters where a
> hundred foot radius for Mr. Devoldere's 0.35 wavelength dense 80m radial
> field runs into the street and through three or four adjacent houses :>)
> 
> At my place that would be through my house, across my driveway, through
> neighbor Tim's deer fence, across his driveway and into his wife's flower
> garden, and toward the back into dense woods where radials are problematic
> elevated or buried.
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Re: [Elecraft] [OT] end-fed halfwave antennas

[Wes Stewart]

Since this was individually addressed to me as well at the reflector, I guess 
I'm expected to respond.


I will keep it brief.  I don't recall Devoldere saying anywhere in his book that 
end-fed half-waves didn't work.  Also, he wasn't advocating 0.35 lambda radials, 
he cited Brown having calculated that the current peaked 0.35 lambda from the 
base.  So you're making that up.  When contest scores become supporting 
evidence, I have nothing else to offer.



On 2/14/2017 9:48 AM, Guy Olinger K2AV wrote:

In spite of ON4UN's 4.3, I stand by my prior statements concerning the
excellence of end-fed half wave antennas (EFHW), and their non-existent
requirements for vast counterpoise. In that specific regard, ON4UN is
unfortunately off the mark. More on that below.

Those of you using the becoming popular (?) EFHW portable antennas with
your excellent Elecraft portable rigs, you do NOT need to worry about
putting down a dense 0.35 wavelength radial field for them to work very
nicely.

I've had 50 plus years experience with 80m EFHW antennas, particularly the
EFHW inverted L or EFHWL. I, and all those I have helped install one to
improve their signal, have had very successful experience with EFHW aerial
wires. It's long-term lack of general popularity among hams has always been
curious to me. I personally attribute that to the lack of a robust
commercial **remote** tuner **made for the purpose** to go at the base. An
off-the-shelf version has always been needed to serve hams who for whatever
reason are unable or disinclined to construct these devices for themselves.

None of this 50+ years of excellent EFHW experience included a 0.35
wavelength radial field. They all included very minimalist counterpoise,
including maybe one hand's worth fed against a ground rod. I remember one
just outside a window and within a few feet of the property line. I never
recommended a ground rod, but I must admit that those worked tremendously
better than what they were previously using. And it was their house, not
mine. Who knows what kind of blowback they were getting about antennas.
Back then radio could put lines through TV signals and create next door
enemies.

I will further add that an 80 meter end-fed halfwave L, and against very
minimalist ground or counterpoise, is arguably the **best** single wire
80/75m antenna for **both** DX and local contacts, and as such a real
winner for small lot situations. Especially for those small lotters where a
hundred foot radius for Mr. Devoldere's 0.35 wavelength dense 80m radial
field runs into the street and through three or four adjacent houses :>)

At my place that would be through my house, across my driveway, through
neighbor Tim's deer fence, across his driveway and into his wife's flower
garden, and toward the back into dense woods where radials are problematic
elevated or buried.

According to Mr Devoldere, that shouldn't work.

OK. Then do this:

http://3830scores.com/editionscores.php?arg=RNfmy1zEgqmmL

On the "Sort by" line set "show" to USA and click on "go"

Do a CTRL-F on K2AV. That will be 256 Q's, 18 zones and 80 countries in a
distracted, very part-time single band effort. Not bragging (I hate
bragging along with most everyone else), but if minimal counterpoise is no
good for voltage-fed antennas, then explain that score by a distracted
decent but otherwise hardly-a-genius operator.

The antenna was an 80EFHWL over a 160m FCP flipped to 80m (explained
elsewhere). That's essentially an elevated pair of 0.125 wavelength wave
radials, +/- 33 feet. Not on the same planet as a dense 0.35 radial field.
So then how does one reconcile the ON4UN ain't gonna work text with most of
a single weekend 80m DXCC in a frequently interrupted part-time effort?

This 80EFHWL was 80m dual-use-ing my 160 inverted L over an FCP, with no
loading coils or additional radiating wires. We have proven this technique
at two other stations with excellent results. More on that, later,
elsewhere.

Back in the day I had an 80EFHWL with two 15 foot buried bare wires running
away from a basement window as a counterpoise. On 80 meters and living in
New York state, taking message traffic on the Eastern Area Net, I was one
of the handful of stations able to consistently check directly into the
Pacific Area Net and forward that traffic directly to Pacific coast
stations when the normal off-net relay failed to show up earlier on 40 or
20 meters. And that was when 4 811A's running the then 1 kW **input** legal
limit could only put about 700 watts on the antenna.

I do have ON4UN's book, and have always and still do hold him in high
regard. But he, like some number of others, have been led astray by Brown's
curious assertion about halfwaves. That's the Brown from Brown, Lewis, and
Epstein of the famous 1937 RCA study on towers and radials.

That ground current format is not duplicated in a NEC4 model of a base-fed
halfwave vertical. Brown's assertions in this regard have pretty well been
discarded as a model 

Re: [Elecraft] [OT] end-fed halfwave antennas

[Morgan Bailey]

I can echo the EFHW experiences as above but, they for me, are slightly
more noisy then a quarter wave vertical. Other than that, that is my only
objection that I have to the EFHW. Every one that I have used has been
excellent.

If you talk to Balun designs they make a 52 to 1 match box that I know for
sure will easily take 800 watts CW on 40. I ran one that way and had no
problems. With power I did use a line isolator inside the shack to protect
against common mode on the shield of the coax. I had no problems with that
set up. It worked and worked well.

I have built 2 tuner boxes for them, I bought 2 old tuners that used an L
network and rewired them to a parallel tank circuit and we, my son NS0R
have used them with 1kw and had great success. No shack problems and they
radiate like a beast because the current is high in the wire and not at the
feed point on the ground. We have used them at Field Day, WPX, Sweepstakes
as our 20 and 40 meter antennas. We both work from a city lot and have no
beams. For us, using these antennas we were able to do 1400 QSO in WPXCW
with a half hearted effort.

We use the same boxes to tune half square antennas as they also have high
impedance feed points.

I personally have used a 20 meter half square...1/4 up then 1/2 wave over
to 1/4 wire elements on 20 and this will make a quarter wave on 80 that we
used with a few radials. So we got 2 bands out of one antenna. In the half
square config on 20 meters, using it as an 80 meter made it NVIS. It did
work.

I am going to have to the me a KX3 or Kx2 some day soon. I wish I had one
now because I am heading to Maine and would like to operate there into
Europe from the coast. And, you can bet I will be taking an EFHW for ease
and portability.

Vy 73,

Morgan NJ8M

On Tue, Feb 14, 2017 at 1:34 PM, Robert Vargas-KP4Y via Elecraft <
elecraft@mailman.qth.net> wrote:

> Agree...I'm a big fan of EFHW. I have made comparisons between an HFHW
> with a short radial and 1/4 WL with a few radials and the EFHW beats the
> 1/4 WL 100% hands down. This is a great example of empirical results
> speaking louder than theoretical predictions.
>
> 73,
> Robert-KP4Y/W4
>
> Sent from my iPhone
>
> > On Feb 14, 2017, at 1:19 PM, Gil G. via Elecraft <
> elecraft@mailman.qth.net> wrote:
> >
> >
> > I will second Guy here.
> > The best antenna I have ever used is the vertical EFHW. I never used a
> counterpoise wire, never felt that tingling in your fingers you might feel
> with a random wire and a metal key.
> > I have used 100mW to 500mW regularly with end feds with great results,
> single hop up to 1300 miles, 5K miles on 1W.
> > I say that having built all kinds of antennas and used them in all sorts
> of configurations, random wires, with and without counterpoises, slopers,
> inverted Vs, dipole, Windom, magnetic loops, quad, short whips, yagi, and
> except for the beams nothing beats the EFHW!
> > A horizontal dipole might perform as well but they are rarely high
> enough to perform as well, except of course for NVIS on the lower bands,
> and then, a horizontal EFHW will work as well.
> > The only antenna that came close in performance was a large magnetic
> loop.
> > Whatever the theory says, I am talking about real in-the-field
> performance where nothing comes close.
> > Gil
> > AK4YH & F4WBY
> >
>
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Re: [Elecraft] [OT] end-fed halfwave antennas

[Robert Vargas-KP4Y via Elecraft]

Agree...I'm a big fan of EFHW. I have made comparisons between an HFHW with a 
short radial and 1/4 WL with a few radials and the EFHW beats the 1/4 WL 100% 
hands down. This is a great example of empirical results speaking louder than 
theoretical predictions. 

73,
Robert-KP4Y/W4 

Sent from my iPhone

> On Feb 14, 2017, at 1:19 PM, Gil G. via Elecraft  
> wrote:
> 
> 
> I will second Guy here.
> The best antenna I have ever used is the vertical EFHW. I never used a 
> counterpoise wire, never felt that tingling in your fingers you might feel 
> with a random wire and a metal key.
> I have used 100mW to 500mW regularly with end feds with great results, single 
> hop up to 1300 miles, 5K miles on 1W.
> I say that having built all kinds of antennas and used them in all sorts of 
> configurations, random wires, with and without counterpoises, slopers, 
> inverted Vs, dipole, Windom, magnetic loops, quad, short whips, yagi, and 
> except for the beams nothing beats the EFHW!
> A horizontal dipole might perform as well but they are rarely high enough to 
> perform as well, except of course for NVIS on the lower bands, and then, a 
> horizontal EFHW will work as well.
> The only antenna that came close in performance was a large magnetic loop.
> Whatever the theory says, I am talking about real in-the-field performance 
> where nothing comes close.
> Gil
> AK4YH & F4WBY
> 

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Re: [Elecraft] [OT] end-fed halfwave antennas

[Irma Linas]

EFHW is a great antenna. It works but only if tuned correctly. Bad news is
 it would be difficult to do the tune job for any ATU, even the Elecraft,
due to the very high impedance ( up to the 5kohms). Please read everybody
the aticles by the EFHW guru here : http://www.aa5tb.com/efha_wrk.html.
STeve explains very clearly the whole theory behind the EFHW, the length of
"counterpoise" etc.

I have built and used many of the EFHW antennas in different configurations
, including usage of the loading coils in the multiband operations in order
to make the wire  shorter on the low bands. The tuner is the simplicity in
itself if used on qrp levels. For the higher power levels the
coil/capacitor choice must  be high ( very high!) RF voltage- proof.

Surely , the tuner , as good as Electaft makes, and the random lenght NON
resonant wire is the excellent solution for the portable work but then you
need a kind of ground whatever you can get at hand. Have tried it for many
years with the Elecraft T-1 tuner with great success working 5 W from the
hotels accross Europe tuning anything I could- window frames, rain water
pipes, random pieces of wire, :)...

73 de Linas LY2H, ex ON4BHP

On 2017 vas. 14, an at 20:20 Gil G. via Elecraft 
wrote:

>
> I will second Guy here.
> The best antenna I have ever used is the vertical EFHW. I never used a
> counterpoise wire, never felt that tingling in your fingers you might feel
> with a random wire and a metal key.
> I have used 100mW to 500mW regularly with end feds with great results,
> single hop up to 1300 miles, 5K miles on 1W.
> I say that having built all kinds of antennas and used them in all sorts
> of configurations, random wires, with and without counterpoises, slopers,
> inverted Vs, dipole, Windom, magnetic loops, quad, short whips, yagi, and
> except for the beams nothing beats the EFHW!
> A horizontal dipole might perform as well but they are rarely high enough
> to perform as well, except of course for NVIS on the lower bands, and then,
> a horizontal EFHW will work as well.
> The only antenna that came close in performance was a large magnetic loop.
> Whatever the theory says, I am talking about real in-the-field performance
> where nothing comes close.
> Gil
> AK4YH & F4WBY
> --
> Sent from Mail.Ru app for Android Tuesday, 14 February 2017, 05:48PM
> +01:00 from Guy Olinger K2AV  k2av@gmail.com :
>
> >In spite of ON4UN's 4.3, I stand by my prior statements concerning the
> >excellence of end-fed half wave antennas (EFHW), and their non-existent
> >requirements for vast counterpoise. In that specific regard, ON4UN is
> >unfortunately off the mark. More on that below.
> >
> >Those of you using the becoming popular (?) EFHW portable antennas with
> >your excellent Elecraft portable rigs, you do NOT need to worry about
> >putting down a dense 0.35 wavelength radial field for them to work very
> >nicely.
> >
> >I've had 50 plus years experience with 80m EFHW antennas, particularly the
> >EFHW inverted L or EFHWL. I, and all those I have helped install one to
> >improve their signal, have had very successful experience with EFHW aerial
> >wires. It's long-term lack of general popularity among hams has always
> been
> >curious to me. I personally attribute that to the lack of a robust
> >commercial **remote** tuner **made for the purpose** to go at the base. An
> >off-the-shelf version has always been needed to serve hams who for
> whatever
> >reason are unable or disinclined to construct these devices for
> themselves.
> >
> >None of this 50+ years of excellent EFHW experience included a 0.35
> >wavelength radial field. They all included very minimalist counterpoise,
> >including maybe one hand's worth fed against a ground rod. I remember one
> >just outside a window and within a few feet of the property line. I never
> >recommended a ground rod, but I must admit that those worked tremendously
> >better than what they were previously using. And it was their house, not
> >mine. Who knows what kind of blowback they were getting about antennas.
> >Back then radio could put lines through TV signals and create next door
> >enemies.
> >
> >I will further add that an 80 meter end-fed halfwave L, and against very
> >minimalist ground or counterpoise, is arguably the **best** single wire
> >80/75m antenna for **both** DX and local contacts, and as such a real
> >winner for small lot situations. Especially for those small lotters where
> a
> >hundred foot radius for Mr. Devoldere's 0.35 wavelength dense 80m radial
> >field runs into the street and through three or four adjacent houses :>)
> >
> >At my place that would be through my house, across my driveway, through
> >neighbor Tim's deer fence, across his driveway and into his wife's flower
> >garden, and toward the back into dense woods where radials are problematic
> >elevated or buried.
> >
> >According to Mr Devoldere, that shouldn't work.
> >
> >OK. Then do this:
> >
> 

Re: [Elecraft] [OT] end-fed halfwave antennas

[Bill Johnson]

Wes,  Thank you for the references!
73,
Bill
K9YEQ



-Original Message-


It is really unfortunate that advice like this continues to be...excuse the 
pun...propagated on forums such as this, when there is so much published 
information to the contrary freely available on the Internet and/or in books in 
your local library.

I have already quoted one source but I'll do it again for emphasis. (Hopefully, 
the formatting will survive)

  Devoldere in "Low-Band DXing", Chapter 9 says:

4.3. The Radial System for a Half-Wave Vertical
Here comes another surprise. A terrible misconception
about voltage-fed verticals is that they do not require either a
good ground or an extensive radial system.

4.3.1. The Near Field
If you measure the current going into the ground at the
base of a λ/2 vertical, the current will be very low (theoretically
zero). With λ/4 and shorter verticals, the current in the radials
increases in value as you get closer to the base of the vertical.
That’s why, for a given amount of radial wire, it is better to
use many short radials than just a few long ones.
With voltage-fed antennas, however, the earth current
will increase as you move away from the vertical. Brown
(Ref 7997) calculated that the highest current density exists
at approximately 0.35 λ from the base of the voltage-fed
λ/2 vertical. Therefore it is even more important to have a good
radial system with a voltage-fed antenna such as the voltage-fed
T or a λ/2 vertical. These verticals require longer radials
to do their job efficiently compared to current-fed verticals.

Another invaluable source is Rudy Severns, http://www.antennasbyn6lf.com/ 
Rudy's work is meticulously measured, beautifully documented and presented.  He 
has written many articles for QEX, which are available on his site or via an 
Internet search.

Wes  N7WS

On 2/12/2017 5:17 AM, Guy Olinger K2AV wrote:
> 
>
> So it is that over the years, especially on 80m, many have shown up on 
> the air with amazingly inefficient antennas on 80m. They would check 
> into 80m traffic nets with really puny signals. Many of these weak 
> signals were excellently solved by going to an end-fed halfwave L fed 
> with a matching network (usually a tapped coil in parallel with a 
> capacitor) against some horrible ground. Grounds like a couple of 
> buried bare wires running away from a basement window, or even a 
> ground rod, did not matter in series with the end-feds' feed Z's in the 1000, 
> 2000 ohm range and up.

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Re: [Elecraft] [OT] end-fed halfwave antennas

[Wes Stewart]

It is really unfortunate that advice like this continues to be...excuse the 
pun...propagated on forums such as this, when there is so much published 
information to the contrary freely available on the Internet and/or in books in 
your local library.


I have already quoted one source but I'll do it again for emphasis. (Hopefully, 
the formatting will survive)


 Devoldere in "Low-Band DXing", Chapter 9 says:

   4.3. The Radial System for a Half-Wave Vertical
   Here comes another surprise. A terrible misconception
   about voltage-fed verticals is that they do not require either a
   good ground or an extensive radial system.

   4.3.1. The Near Field
   If you measure the current going into the ground at the
   base of a λ/2 vertical, the current will be very low (theoretically
   zero). With λ/4 and shorter verticals, the current in the radials
   increases in value as you get closer to the base of the vertical.
   That’s why, for a given amount of radial wire, it is better to
   use many short radials than just a few long ones.
   With voltage-fed antennas, however, the earth current
   will increase as you move away from the vertical. Brown
   (Ref 7997) calculated that the highest current density exists
   at approximately 0.35 λ from the base of the voltage-fed
   λ/2 vertical. Therefore it is even more important to have a good
   radial system with a voltage-fed antenna such as the voltage-fed
   T or a λ/2 vertical. These verticals require longer radials
   to do their job efficiently compared to current-fed verticals.

Another invaluable source is Rudy Severns, http://www.antennasbyn6lf.com/ Rudy's 
work is meticulously measured, beautifully documented and presented.  He has 
written many articles for QEX, which are available on his site or via an 
Internet search.


Wes  N7WS

On 2/12/2017 5:17 AM, Guy Olinger K2AV wrote:



So it is that over the years, especially on 80m, many have shown up on the
air with amazingly inefficient antennas on 80m. They would check into 80m
traffic nets with really puny signals. Many of these weak signals were
excellently solved by going to an end-fed halfwave L fed with a matching
network (usually a tapped coil in parallel with a capacitor) against some
horrible ground. Grounds like a couple of buried bare wires running away
from a basement window, or even a ground rod, did not matter in series with
the end-feds' feed Z's in the 1000, 2000 ohm range and up.


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Re: [Elecraft] [OT] end-fed halfwave antennas

[Guy Olinger K2AV]

The EFHW antenna was not invented by anyone alive today. It is very
definitely a classic antenna. It's just a very efficient antenna that has
gone through periods of forgotten usefulness.

An end-fed 80m half wave L, or other "bent" form, is an antenna that has
been used successfully at least since 1957 when I first saw one as a 14
year old. The at-the-time 52 year old AM BC chief engineer who explained it
to me, alas, is long gone. He would be 111 today.  No one used center
loading coils back then. Puts the max current in the antenna on the loading
coil. If you couldn't make it long enough, you made it long as you could
and the difference got soaked up in the matching network.

Hams seem irresistibly drawn to antennas where "matching the antenna"
consists of connecting it directly to a piece of coax.

So it is that over the years, especially on 80m, many have shown up on the
air with amazingly inefficient antennas on 80m. They would check into 80m
traffic nets with really puny signals. Many of these weak signals were
excellently solved by going to an end-fed halfwave L fed with a matching
network (usually a tapped coil in parallel with a capacitor) against some
horrible ground. Grounds like a couple of buried bare wires running away
from a basement window, or even a ground rod, did not matter in series with
the end-feds' feed Z's in the 1000, 2000 ohm range and up.

The improvement in signal strength converting to the EFHWL was often
remarkable, as in two or three S units, or as said back then, "gone from a
peep to a pounder".

The EFHWL has never been popular because it always requires a matching
device *at the base of the wire*, and without some remote switching of taps
and/or cap value, only covered 50-100 kHz of the band in today's common SWR
limits. However back then that was often extended as rigs with tetrode tube
finals were far more tolerant of antenna Z. At QRP, particularly among the
SOTA and backpacker crowd, the EFHW is making a comeback.

If we ever get a good manufactured off-the-shelf *QRO* end-fed tuner, the
80m EFHWL will get popular and stay that way.

73, Guy


On Sat, Feb 11, 2017 at 7:59 PM, inventor61 .  wrote:

> My Elecraft rigs are connected to guyed, end-fed half wave vertical
> monopole antennas, one each on 30 meters and 40 meters.  I use
> tapped-L-parallel-C matching networks at the base of these antennas, which
> are ground mounted and insulated.
>
> They radiate at the horizon, or darned close to it, and don't need any
> inconvenient ground radial wires, or even a particularly low impedance
> earth.  To me, that fact alone was worth any other effort.
>
> I got inspiration for my antennas from similar designs used at the
> following addresses ... each have historical markers, incidentally ... if
> you are curious, you can use Google Maps to see them yourself:
>
> 764 Tylersville Road, Mason, Ohio
>
> 8068 Concord Road, Brentwood, Tennessee
>
> While the hams who designed and installed these antennas had bigger budgets
> than I do, they had the same goals.
>
> For portable use, if you can manage an overhead tree branch at a suitable
> height, only 60 feet of wire interrupted in the center with 47 microHenrys
> of L yielded a center-loaded EFHW I used *very* successfully on 80 meters.
> Again, no radials needed, a major consideration to me.  The feedpoint
> impedance was quite high, so the matching network I had to make was
> interesting but still do-able.
>
> Steve KZ1X/4
> K2 #771
> K3 #6081
> __
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
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>
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> Message delivered to k2av@gmail.com
>
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[Elecraft] [OT] end-fed halfwave antennas

[inventor61 .]

My Elecraft rigs are connected to guyed, end-fed half wave vertical
monopole antennas, one each on 30 meters and 40 meters.  I use
tapped-L-parallel-C matching networks at the base of these antennas, which
are ground mounted and insulated.

They radiate at the horizon, or darned close to it, and don't need any
inconvenient ground radial wires, or even a particularly low impedance
earth.  To me, that fact alone was worth any other effort.

I got inspiration for my antennas from similar designs used at the
following addresses ... each have historical markers, incidentally ... if
you are curious, you can use Google Maps to see them yourself:

764 Tylersville Road, Mason, Ohio

8068 Concord Road, Brentwood, Tennessee

While the hams who designed and installed these antennas had bigger budgets
than I do, they had the same goals.

For portable use, if you can manage an overhead tree branch at a suitable
height, only 60 feet of wire interrupted in the center with 47 microHenrys
of L yielded a center-loaded EFHW I used *very* successfully on 80 meters.
Again, no radials needed, a major consideration to me.  The feedpoint
impedance was quite high, so the matching network I had to make was
interesting but still do-able.

Steve KZ1X/4
K2 #771
K3 #6081
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

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