++++++++++++++++++

See Antenna Longwire

++++++++++++++++++
Reply-To: <la3za at qsl.net>
From: "Sverre Holm - LA3ZA" <la3za at qsl.net>
To: <elecraft at mailman.qth.net>
Subject: RE: [Elecraft] field ops
Date: Mon, 11 Feb 2002 23:13:55 +0100

My RSGB book "The Antenna File" from 2001 has an article by G3CCB on
"Taming the End-Fed Antenna". He has made a chart of lengths that are
favorable based on the criterion that he wanted to avoid lengths close
to half wavelength (actually between 3/8 and 5/8) in order to avoid a
high impedance, and simplify tuning. The result is three recommended
lengths:

10.5 m: good for 80, 40, 30, 17, 15, and 12 m (not 160, 20, 10 m)
15.5 m: good for 80, 40, 20, with some tolerance at 17 and 15, and 12 m
(not 160, 30, 10 m)
26.5 m: good for 160 - 12 m (not 10 m) 

I have not tried these lengths myself, but would be interested to know
if there is any experience around that agrees or disagrees with these
figures.



Sverre Holm, LA3ZA
Asker, Norway (59.8N, 10.4E)
---------------------------------
www.qsl.net/la3za



-----Original Message-----
From: elecraft-admin at mailman.qth.net
[mailto:elecraft-admin at mailman.qth.net] On Behalf Of WA5PB
Sent: 11. februar 2002 22:13
To: elecraft at mailman.qth.net
Subject: [Elecraft] field ops


Hey gang,

When tossing a random end over the tent and into the trees, what is
pretty much the minimum useful length.  How long for a counterpoise.  I
am using the ATU and am planning on working as many bands as possible
10-80.

Thanks,
WA5PB,
Bill Allen

+++++++++++++++++++
Reply-To: <rondec at easystreet.com>
From: "Ron D' Eau Claire" <rondec at easystreet.com>
To: <elecraft at mailman.qth.net>
Subject: RE: [Elecraft] field ops
Date: Mon, 11 Feb 2002 13:46:16 -0800

> When tossing a random end over the tent and into the trees, what
> is pretty much the minimum useful length.  How long for a
> counterpoise.  I am using the ATU and am planning on working as
> many bands as possible 10-80.
>
> Thanks,
> WA5PB,
> Bill Allen
>

The minimum useful length is a few feet - long enough for the ATU to find a
match - if you don't care how well you get out.

If you want the rig to show some sort of "performance", use 1/4 wavelength
as the absolute minimum length and 1/2 wavelength is a LOT better. In that
sort of situation, the difference between 1/4 and 1/2 wavelength of wire
heading up into the trees can be several "S" units at the other end. The
problem becomes finding a tall enough tree or a strong enough throwing arm
for 80 and 40 meters (I have a slingshot and some small fishing weights, but
be careful! They are considered "weapons" in many parts of the USA!).

Put some monofilament fishline leader on the far end of the wire. You want
it insulated from the foliage.

The counterpoise is 1/4 wavelength long to provide a low impedance point at
the rig. So you either need to have some sort of loading system to bring it
to 'resonance' on each band, or run a 1/4 wavelength long wire for each
band.

Ron AC7AC
K2 # 1289

++++++++++++++++++++
From: "Hayden" <mhayden at gettysburg.edu>
To: "WA5PB" <wa5pb at yahoo.com>
Sent: Monday, February 11, 2002 3:26 PM
Subject: RE: [Elecraft] field ops



a while back, there was a note on the reflector to try an 80 ft radiator to
the K1 center conductor, and a 33 ft counterpoise and alligator clop to the
bnc shell..  I think Bruce, N7CEE recommended it.  I tried it, and it works
great for 40/20, which is my K1's setup.

I can't try it on the other bands though.

73
Mike AK3F
K1#522

++++++++++++++++++
From: "Stuart Rohre" <rohre at arlut.utexas.edu>
To: "WA5PB" <wa5pb at yahoo.com>, <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] field ops
Date: Mon, 11 Feb 2002 15:34:40 -0600

First, I have had uniformly poor results from random wires or end fed
quarter wave wires.  YOU MUST have a counterpoise or one radial.

You could, with a transmatch, try 33 feet for the antenna wire, and 17 feet
for the counterpoise.  Various arrangements of the wire and counterpoise re
each other may give varying results.  I think I would emulate a dipole, ie
33 feet high and clear as possible, and 17 feet 180 degrees in other
direction like half of a dipole that fell down.
73,
Stuart K5KVH

++++++++++++++++++
Reply-To: <rondec at easystreet.com>
From: "Ron D' Eau Claire" <rondec at easystreet.com>
To: <elecraft at mailman.qth.net>
Subject: RE: [Elecraft] field ops
Date: Mon, 11 Feb 2002 16:01:54 -0800

> My RSGB book "The Antenna File" from 2001 has an article by G3CCB on
> "Taming the End-Fed Antenna". He has made a chart of lengths that are
> favorable based on the criterion that he wanted to avoid lengths close
> to half wavelength (actually between 3/8 and 5/8) in order to avoid a
> high impedance, and simplify tuning....
> Sverre Holm, LA3ZA

The problem with adjusting the length of the end-fed wire to achieve a low
feed impedance is that you again become dependent upon a good ground for
good efficiency.

Think of the radiation resistance of the antenna and the ground resistance
as being in series. The r-f flows through both of them. The higher
resistance will consume the greater power.

So you want the radiation resistance to be many times the ground resistance.

The radiation resistance will be about 35 ohms for a 1/4 wave wire. A short
antenna less than 1/4 wavelength like many of those used for portable work
may show a radiation resistance of a fraction of one ohm.

If you use a single counterpoise wire, you might see a 'ground' resistance
of about 35 ohms. In that case, half of your r-f goes to the antenna if you
have a 1/4 wavelength radiator. Half warms the earthworms. If the antenna is
less than 1/4 wave - say 1/8 wave where the radiation resistance is about 2
ohms, then you can expect perhaps 95% of your power to be warming the
earthworms and at best 5% being radiated.

Even if you make the end fed wire longer than 1/2 wave  - say 3/4 wave where
you will again see a low impedance at the fed end, the same situation
continues. It's not as bad. A 3/4 wave wire will have a radiation resistance
well above 35 ohms, but you are still penalizing yourself by not selecting
the highest impedance point where you can to feed it. Being right on 1/2
wave, or even a multiple of 1/2 wave, will usually produce an impedance
outside the range of most ATU's to handle (even the KAT2). But the most
efficient end-fed wire system is where you are as close to it as possible.

Of course, the other way to make the end-fed wire more efficient is to
install a better ground. You can place about 60 radials at least 0.2
wavelength long on the ground around the rig and use a short wire with
rather good efficiency. But that is pretty hard for most of us to do at
home, much less at a campsite!

Usually, making the antenna closer to 1/2 wave long to raise the radiation
resistance is easier than lowering the ground resistance - at least on the
higher frequency bands.

Ron AC7AC
K2 # 1289

++++++++++++++++
Date: Mon, 11 Feb 2002 17:27:52 -0500
To: "WA5PB" <wa5pb at yahoo.com>
From: Charles Greene <W1CG at QSL.net>
Subject: Re: [Elecraft] field ops
Cc: <elecraft at mailman.qth.net>

At 03:13 PM 2/11/2002 -0600, WA5PB wrote:
>Hey gang,
>
>When tossing a random end over the tent and into the trees, what is pretty 
>much the minimum useful length.  How long for a counterpoise.  I am using 
>the ATU and am planning on working as many bands as possible 10-80.
>
>Thanks,
>WA5PB,
>Bill Allen
I use a W3EDP antenna.  It's an 85' wire.  One 17' counterpoise for 40-15, 
one 67' one for 80 and one 16' one for 10.  Lay the counterpoises on the 
ground in any configuration.


73, Chas, W1CG

+++++++++++++++++++
Date: Fri, 15 Feb 2002 08:01:57 -0500
From: "Dave" <wr3i at earthlink.net>
To: "Low Power Amateur Radio Discussion" <qrp-l at lehigh.edu>,
        aweiss at usd.edu
Subject: [120016] Re: 30 meter antenna


You could try a 1/4 wave wire attached to center of coax with the 
shield attached to a steel tent peg for ground make a fine bottom 
fed sloper vertical just sling the free end into a tree supported with 
rope or string
Dave

+++++++++++++++++++
Date: Fri, 15 Feb 2002 06:02:09 -0500
From: John R Kirby <n3aaz-qrp at juno.com>
To: qrp-l at Lehigh.EDU, jman0iin at attbi.com
Subject: [120013] Re: 30 meter antenna


>>Question . . . 

?"Does anyone know of a good 30 meter antenna (or drawing
?with lengths, etc for one) for portable use, end-fed
?with coax, and doesn't require a tuner?"

I am not sure there is a soulation to the above question, 
however . . . 
here is a NO COAX system that will work . . . 
on most frequencies . . . 
plans to build from scratch . . . 
simple and works every time . . . 
and **if desired** no feed line required.

The all band portable antenna 'stuff (below) is my (N3AAZ) work,
it was published in the Nor-Cal QRPp newsletter
(a few issues back), see . . . 
 THE >L< NETWORK REVISITED  
for the schematic and figures or
e-mail me for a .gif attachment.

There is a picture of my >L< (the inductor)  on the
QRPp International Radio Club's Web site:
http://www.QRPp-I.com

An old five tube radio can provide the 355uF variable >C<
. . .  OR . . . because the >L< has taps (it is variable)
just *parallel*  >C< to almost any variable capacitor.

A tuning indicator is required, the GQRP web site has an
outstanding bridge type (again . . . simple AND it WORKS)
plans to build from scratch.


73, John (N3AAZ)


>>>>>>> START QRPp TEXT >>>>>>>> 

THE >L< NETWORK REVISITED

What do these terms have in common?

QRP, backpacking, efficiency, zero-weight feedline, low pass filter,
stealth, home brew, omni-directional, all band, tuner, and . . . 

Answer . . . One inductor and one capacitor, the >L< Network

Figure 1 (e-mail me direct  for an attachment "EXPORT -L- . gif") shows
the no feedline, portable, long wire antenna system I used with
outstanding success a few years ago while camping in a pop-up. This setup
will match most 100 foot long wire antenna configurations form 80 through
10 meters. Since the components are small, light, easy to pack and deploy
this configuration also makes for an outstanding spare or emergency
antenna. 

The inductor is 21 turns of solid 18 AWG wound on a "stack" of three,
Micrometals, RED (MIX 2), T94-2, powdered iron cores, with a "tap" placed
every three turns (Figure 3). The capacitor is a 200 pico Farad variable.
The antenna wire is a small roll of inexpensive, insulated, zip cord. You
will need "alligator" clips and a tuning indicator. The earth ground
system is several strands of zip cord in parallel. The ground rod just a
common screwdriver with a  vice-grip for hammer and wire clamp.

Feedline is not required (ssee Figure 1) because the >L< network is
connected direct between transceiver and base (the feed point) of the
antenna. The feedpoint of the long wire antenna is located inside the
shack (camper, tent or sleeping bag).

The tuning indicator can take many forms. It is noteworthy to say, if it
takes too long to adjust ANY antenna tuner, the "final RF amplifier" in
your transmitter may be at risk to over heating. I suggest, install a 10
dB attenuator (figure 4) between the transmitter and tuner to help
protect the PA transistor during the initial adjustment. The "attenuator"
technique is NOT a guarantee. The safest method is reduced transmitter
power and short (intermittent) "key down" adjustments. The attenuator is
removed for final adjustment and QSOs.

The >L< Network 

For the purpose of this discussion the term long wire antenna refers to a
non resonant wire element that is either, straight line, zigzag,
horizontal, vertical, or any combination, but always longer than a half
wave at it's operating frequency. A counterpoise is not required. An
earth ground helps.

The approximate half wave length in feet can be determined by dividing
468 by the operating frequency in MHz. Example, Length(ft) = 468 /
F(MHz), a half wave at 7.04 MHz is approximately 66.5 feet.
 
How does the >L< network match a low impedance transmitter to high
impedance long wire? Connect the coil in series between the XCVR / ANT
junction and connect the capacitor from the COIL / ANT junction to the
XCVR chassis and earth ground, see figure 1. 

The >L< network will also match most random, non resonant, "short", low
impedance antenna. The short antenna refers to a wire or rod (whip),
straight line, zigzag, vertical, horizontal or any combination but always
less than a quarter wave at it's operating frequency. The short antenna
is a compromise, efficiency can be poor and a counterpoise is required
for best results.  When matching a highZ (50 Ohm, transmitter) to lowZ
(15 Ohm, short vertical) the inductor is connected in series between
source and load. The capacitor is "shunt" or parallel to the source, see
figure 2. Note, this connection is unlike the "long" example above.

Today our camper is a fifth-wheel with an eight-foot aluminum ladder
rack. I just add a Radio Shack # 21-937B Rack Mount Bracket to create a
very nice whip antenna support AND ladder rack counterpoise antenna
system. The base of my antenna is now atop that ladder rack so a feedline
is required.  NOTE . .  .Feedline may assert a length problem and affect
the impedance the transmitter looks into when there is a reactive
component on the other end.  Why? In this case, the load (on the
feedline) is a non-resonant length of wire, i.e., a reactive  component.
Therefore, the transmitter in Figure 2 will only see 50 Ohms when there
is a half wave, 50 Ohm feedline connected. Why? A half wave feedline
"repeats" at it's INPUT what it "sees" at it's OUTPUT and the >L< network
for the "short" antenna was designed to match 50 Ohm.

Conclusions . . .
 
Exclude . . . the feedline and it is noteworthy to say, the >L< network
shown in figures 1 and 2 match the Smith Chart  ' yin / yang '  curves,
i.e., there is most likely no point on the chart one or the other network
configuration will not match to 50 Ohm.  

Include. . .  a feedline of random length and the >L< network may not
tune all the bands, however, the operative word is "random" length feed
line.  Change the feed line length a foot or two and try again.

Ah 'little Theory and Math (very little). . . 

The impedance presented by the end of a random wire can range over a very
large playing field, from only a few Ohms to several thousand Ohms.  This
calculation shows just one example, how to match a 50 Ohm source to a 377
Ohm load using the >L< network.

First find K
K = Square root of ((HighZ  /  LowZ) - 1)
K =  ( ( 377 / 50 ) -1) ^ 0.5
K = 2.56

Next find X(L), reactance of the matching coil
X(L) = K times LowZ
X(L) = 2.56 X 50
X(L) = 128 Ohm

Next find the matching coil value
If X(L) = 2 Pi  F L
then L = X(L) / 2 Pi F

L = 128  / (6.28 X 7.04E6)  >>7.040 MHz<<
L = 2.89E-6 or (2.89 uH)
The series inductor should be approximately 3 micro Henry

Next find X(C), reactance of the matching capacitor
X(C) = HighZ / K
X(C) = 377 / 2.56 
X(C) = 147.26 Ohm

Next find the matching capacitor value
if  X(C) = 1 / (2 Pi  F  C)
then C = 1 / (2 Pi  F  X(C))

C = 1 / ( 6.28 X 7.04E6 X 147)
C = 1.5E -10
(1.5E -10) is 0.15 nano Farad or 0.00015 micro F or 150 pico F

For a lower SWR  : > )  make C a variable capacitor and (if required)
parallel fixed value capacitors to extend the range or series fixed
values to decrease the range (total value).

Thank You . . . 

This article is the result of my response to a thread on qrp-l.  Ade,
W0RSP wrote in part . . . "If you really are worried about the weight of
a feedline, why use one at all?  Instead put up an end fed antenna
coupled to a tuner".  Doug, KI6DS, read my solution to the feedline
weight problem and ask to publish my humble input. This is indeed an
honor, thank you Doug, for the invitation and privilege to publish in
QRPp.  Special thanks go to Bill, KD7S and L.B., W4RNL, for their patient
guidance and knowledgeable assistance. 

I welcome all comment, >>n3aaz-qrp at juno.com<<

John, N3AAZ

<<< END TEXT <<<   

enjoy . . . 

73,

John
N3AAZ
FM 19 xa 

++++++++++++++++++
Reply-To: "Don Wilhelm" <w3fpr at peoplepc.com>
From: "Don Wilhelm" <w3fpr at peoplepc.com>
To: <casey.jay at gte.net>, <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] K1 & Long Wire Antenna
Date: Mon, 25 Feb 2002 20:59:04 -0500


----- Original Message -----

> How do you connect a long wire antenna to the K1?  I'm new at this
> antenna  items, but how is the longwire connected to the  BNC connector
> of the K1?  It may be a dumb question, but I've learned a dumb question
> is one never asked!
>

Donn,
I can think of 2 ways to do the job, but I'm certain there are many others.
One is to make up a 'dongle' of a few inches of coax - BNC connector on one
end and connectors of your choice on the center conductor and braid of the
other end.
The other way is to use a ready made adapter - BNC to banana jack adapters
are commonly used to connect test leads to a 'scope BNC input, or I recall a
discussion a while back about a BNC to 5 way binding post adapter - I have
not seen one of those, but it would be nice.

73,
Don Wilhelm  - Wake Forest, NC   W3FPR home page: http://www.qsl.net/w3fpr/
  QRP-L # 485   K2  SN 0020   mailto: w3fpr at arrl.net

*** Life is what happens when you're making other plans -- Mike Cross  ***

++++++++++++++++++++
Reply-To: <rondec at easystreet.com>
From: "Ron D' Eau Claire" <rondec at easystreet.com>
To: <elecraft at mailman.qth.net>
Subject: RE: [Elecraft] K1 & Long Wire Antenna
Date: Mon, 25 Feb 2002 19:24:53 -0800

 A very simple way is to pick up a BNC/SO-239 adapter to go in the back of
your K1. Radio Shack sells them. That gives you a regular female "UHF" type
coaxial connector. Then get a standard banana plug. It will seat very nicely
in the center pin hole of the coaxial connector jack.

And if you ever find yourself somewhere where you want to hook up to a
'regular' coaxial connector, you already have the adapter in your kit.

Ron AC7AC
K2 # 1289

> How do you connect a long wire antenna to the K1?  I'm new at this
> antenna  items, but how is the longwire connected to the  BNC connector
> of the K1?  It may be a dumb question, but I've learned a dumb question
> is one never asked!
> Tnx,
> 72,73 Donn, WB4ZWT
> 66 and still learning

++++++++++++++++++++
Date: Sun, 24 Mar 2002 16:52:39 -0700
From: "James R. Duffey" <jamesd1 at flash.net>
To: <Schunn99 at aol.com>, qrp-l <qrp-l at lehigh.edu>
Subject: [123095] Random thoguhts on  random wire antennas

The random wire is called random because it is not generally a specific
length; that is it is usually long enough to go between convenient supports.

It can be entirely horizontal, sloping, or part vertical and part
horizontal.

A tuner is usually required. A tee network or ell network circuit will work
fine. If the antenna length is a multiple of half wavelengths, then a
parallel L-C circuit will work fine  A Z match will also work, but tuning
can be touchy. Most commercial tuners are of the tee type. Just connect the
wire to the hot lead of the tuner. A banana plug  (wander plug for the Gs on
the list) is convenient to use, fasten it to the end of a wire. It will fit
perfectly in the center conductor of a SO-239 (UHF) coaxial connector.

Some lengths are better than others. A half wave or multiple of that is
usually easiest to handle with respect to tuning and ground. A length of 130
feet or so is about a multiple of half wavelengths from 80 M to 10 M and is
a good choice for length. For a half wave system, a single 1/4 wave resonant
radial on each band is adequate. For frequencies at which the antenna is a
quarter wavelength or odd multiples of a quarter wavelength the ground
system is more important and efficiency can suffer if a good ground is not
supplied.

On low frequencies, the directivity will at right angles to the antenna. At
higher frequencies, the directivity will be off the ends of the antenna. At
the longer lengths, the nulls can be sharp. You can have good coverage to
one area of the world on one band, and have a null there on other bands.
Horizontal antennas less than a half wavelength high won't have much
directivity.

If part of the antenna runs vertical, then the vertical length should be
less than 5/8 wavelength on the highest band if high angles of radiation on
that band is to be avoided.

-- 
James R. Duffey KK6MC/5
Cedar Crest, NM   DM65

+++++++++++++++++
Date: Sun, 24 Mar 2002 18:08:20 -0600
From: Nick Kennedy <nkennedy at tcainternet.com>
To: "'Schunn99 at aol.com'" <Schunn99 at aol.com>,
        "Low Power Amateur Radio Discussion (E-mail)" <qrp-l at Lehigh.EDU>
Subject: [123096] RE: random wire antennas?

It's an end fed antenna that will need a good ground or radials.  Your 
tuner may have an input configuration to match that type of antenna. 
 Whether it will actually be able to match it depends on the length.  If 
you make it around a quarter wave, it should be simple.

But as you said, it's usually used as a multi-band antenna so it may work 
on some bands and not on others until you tweak the length.  I'd make it a 
quarter wave on the lowest band I intended to use it on for starters.

The terms 'random wire', 'end-fed wire' and 'longwire' are often used kind 
of interchangeably, although longwire should imply being a wavelength or 
more long.  They can work OK if you can't get anything else in the air. 
 Biggest disadvantage is that the antenna comes right into the shack, so 
you are radiating power right in the room with you.

As far as 'db' and performance goes, that's too complex to generalize on 
since it will vary with band and length, height, and configuration.  If you 
need to see that, use an analyzer like W7ELs ELNEC or EZNEC.

On how to connect--if your tuner just has a coax connector (BNC) input, 
then connect the random wire to the center pin  and plug it in.  But be 
sure to connect your good ground and/or radials (or counterpoise) to the 
tuner case as well.

I'd look at some of Reg Edwards programs for simple matching circuits for 
this antenna.

72, GL & keep us posted--

Nick, WA5BDU

+++++++++++++++
Date: Sun, 24 Mar 2002 20:54:30 EST
From: ARDUJENSKI at aol.com
To: qrp-l at lehigh.edu
Subject: [123106] Say you want to know about end fed wire antennas?

Want to know about end fed wire antennas?  Take a peek at what this site 
offers:
http://www.qsl.net/wd8rif/archives.htm#antennas

Also you may want to atake a gander at:
http://www.njqrp.org/n2cxantennas/halfer/
http://www.qsl.net/aa5tb/efha.html
http://www.g3ycc.karoo.net/ants.htm
http://www.g3ycc.karoo.net/w3edp.htm
http://www.easystreet.com/~w7zoi/endfeed.html
http://www.natworld.com/ars/pages/back_issues/2000_text/0600_text/dk_vert.html

http://www.g3vgr.co.uk/hw_ant.htm
http://www.qsl.net/wb3gck/tuner.htm

these are a sample of what you can find on www.google.com.

Alan KB7MBI in Woodinville, WA
FISTS 5702  Proud member of ARRL

++++++++++++++++++
Date: Mon, 25 Mar 2002 08:33:20 -0600
From: "W5TB" <w5tb at arrl.net>
To: <Schunn99 at aol.com>,
        "Low Power Amateur Radio Discussion" <qrp-l at Lehigh.EDU>
Subject: [123135] Re: random wire antennas?

----- Original Message -----=20
From: <Schunn99 at aol.com>
To: "Low Power Amateur Radio Discussion" <qrp-l at Lehigh.EDU>
Sent: Sunday, March 24, 2002 4:34 PM
Subject: random wire antennas?


> hi, guys
> I was searching the web and read some qrp websites that mentioned =
random wire=20
> antennas? I know you need a atu and that it is a muti-band antenna. =
Could you=20
> guys give me the specs on that kind of antenna?( db, length, what kind =
of=20
> wire is good to use)=20

I've used these with good success and just installed one at my xyl's =
folks house where we spend a weekend each month. I wanted something =
fairly stealthy so I opted for the random wire using 20 guage twisted =
pair telephone wire I had handy - it's coated with a blue & yellow =
covering which makes it hard to spot unless you know what you're looking =
for.=20

 I simply ran the wire out the window (which has a plywood section so =
they can fit a window air conditioner in the room) -- wrapped it once =
around a 3" TV line standoff just outside the window -- then  up to the =
second story eave where I ran it thru a second  3" TV line standoff -- =
then over the tallest tree limb I could hit about 8' away -- from there =
across trees in back yard as high and nearly straight as I could get it =
( a few zigs and zags up/down,  right/left -- whatever worked  :-) =20

Total length -- unknown, probably 90' - 100' or so. Then I ran a =
counterpoise out a second hole in the plywood, around the corner and =
along the back of the house, keeping it off the ground but low enough to =
be nearly invisible -- maybe 18-20' long?  Tunes fine 80-10 with a =
little MFJ 971 tuner (great because it has a QRP scale for 0-6W)  If it =
didn't I'd adjust the counterpoise length -- if that didn't do the trick =
I'd cut a few feet off the antenna wire.

How does it work? I've worked all states and DXCC running similar =
antennas at 5W. Only a couple hours on this particular one in Paris TX  =
but the first night I worked UR7GW, S52KA, I1YRL and  F5IN (no contest =
on -- returned their CQs) then had nice 5 - 20 minute QSOs with IL, NC, =
SC,TX,OH and IA

> and do=20
> you just attach a bnc connector to one end of the wire and then attach =
the=20
> bnc to the tuner?

yes, I use a 1' section of RG58 between the rig and MFJ tuner BNC on the =
rig end and an SO 259 to the MFJ tuner

Moral -- although it's hard to beat a good dipole fed with open line a =
random wire/counterpoise is a LOT better than an attic antenna (or no =
antenna at al!  Put it up and get on the air  ! ;-)

72, 73, oo    T.E. 'Doc' Drake,  W5TB
Arlington, Texas
FISTS # 5365  QRPARCI # 3532 ARRL Life Member K1 #181 K2#1617=20

++++++++++++++++++
Date: Mon, 25 Mar 2002 10:38:31 -0500
From: Bruce Muscolino <w6toy at erols.com>
To: Schunn99 at aol.com
Cc: Low Power Amateur Radio Discussion <qrp-l at lehigh.edu>
Subject: [123142] Re: random wire antennas?

I've read several of the replies and they are all good.  A random wire
antenna is often the easiest antenna to put up, as it always runs from
here, the rig, to there, a convenient support.  And it has its feed line
built in!

It will work with the simplest of tuners. simple L-networks work very
well.  I put up one here when I bought this house.  It has served me
well for 6 years, only blowing down once, and that was, fortunately,
before I got into this wheelchair!

Please don't overlook the ground circuit.  I use an MFJ artificial
ground.  It allows me to tune the ground current for a maximum with only
about 8 feet of ground wire.  Do not try to use a ground wire and ground
rod!  The length is too hard ot match.  Use resonant counterpoises for
each band if you can't afford a ground tuner.

I have worked all states and DXCC with mine.  Before I moved into this
house I used a random wire antenna made from about 45 feet of #26 magnet
wire.  I had to replace this one every so often, but I also worked all
states and DXCC with it too!.  YOu can find an article about it in the
June 1995 QST.

73

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Date: Mon, 25 Mar 2002 14:36:37 -0500
From: "Larry Spinner" <n2icz at hotmail.com>
To: <N9PUZ at arrl.net>,
        "Low Power Amateur Radio Discussion" <qrp-l at Lehigh.EDU>
Subject: [123152] Re: random wire antennas?

> Question about counterpoises: If you're using an antenna on multiple
> bands can you attach multiple counterpoise wires at the same time? How
> far do they need to separated from one another to remain effective?

> Tim  N9PUZ

I used to use the multiple counterpoise wires attached to my tuner all at
the same time.  I cut one counterpoise for each band I wanted to operate. I
tried to "fan" them out a bit, but I'm not sure they even needded to be
fanned...  They worked FB...   Because I live in a condo, the multiple wires
were running all over the place, which was driving my wife crazy.  As she
put it, "Larry, please this is maddening"!  To an extent she was right...  I
had wires under rugs, along the baseboards, etc.  The vacuum ate a few of
them...  Anyway, I ended buying the MFJ Artifical ground and have never
regretted it.  I now use one wire about 16 feet long tucked along the
baseboard of my operating area and load it up all the bands...  No problem.

Incidentally, I often see threads in here asking about good to reasonable
stealthy antennas for use in condos or apartments.  Try the end fed 1/4 or
1/2 wave antenna with the ground tuner...  You'll never regret it AND you'll
save a boatload of money compared to the "miracle whips","joeys" and others
that are out there that don't and CAN'T function better .....

72 es 73,

Larry
N2ICZ

+++++++++++++++++++
Date: Mon, 25 Mar 2002 16:37:44 -0500
From: "Larry Spinner" <n2icz at hotmail.com>
To: <N9PUZ at arrl.net>,
        "Low Power Amateur Radio Discussion" <qrp-l at Lehigh.EDU>
Subject: [123169] Re: random wire antennas?

> Do you notice any symptoms of RF in the shack area at higher power (up
> to 100W?) I work from a home office and have a couple of pieces of
> equipment that get real unhappy with stray RF. One is the transceiver
> for our wireless DSL service, the other is a multi-line caller-ID box.
>
> Tim  N9PUZ

I rarely run more than 20 watts of power in the Condo.  At QRP levels, I
never have an RFI problem. I would think that at 50 watts and above RFI will
rear its ugly head.  When you think about it, the entire end fed wire is
radiating RF from the antenna tuner.  If you have part of that wire in your
house, condo or shack, part of that radiation is in your house.   The
counterpoises merely "tame" the RF current and allow the current to seek a
balance.  That way, your rig and the tuner are essentially not acting as the
counterpoise.  BUT  that doesn't mean you  won't have RFI.   Actually,
smarter minds here on the list,  than mine, could answer this better..  In a
nutshell, though, I wouldn't run 100 watts to any antenna if part of it was
in the house...  Good luck!

Larry
N2ICZ

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Date: Mon, 25 Mar 2002 16:36:57 -0500 (EST)
From: baltimoremd at baltimoremd.com
To: Tim - N9PUZ <N9PUZ at arrl.net>
Cc: Low Power Amateur Radio Discussion <qrp-l at Lehigh.EDU>
Subject: [123170] Re: random wire antennas?

On Mon, 25 Mar 2002, Tim - N9PUZ wrote:

> Question about counterpoises: If you're using an antenna on multiple
> bands can you attach multiple counterpoise wires at the same time? How
> far do they need to separated from one another to remain effective?
>
I don't know what the "books" say...but my counterpoise system is a 1/4
wave wire for each band(80-10 including WARC) all in one bundle...

Thom

baltimoremd at baltimoremd.com

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Date: Mon, 25 Mar 2002 15:51:14 -0600
From: "George, W5YR" <w5yr at att.net>
To: baltimoremd at baltimoremd.com
Cc: Low Power Amateur Radio Discussion <qrp-l at Lehigh.EDU>
Subject: [123171] Re: random wire antennas?

Fortunately, it is not important for a "counterpoise" to work that it be
exactly resonant when used as you are using them. Just so it is "close" it
will pick up enough r-f to place the open end at max r-f voltage and the
other end connected to the equipment to near zero voltage. And that is what
it is expected to do, and all it can do.

Drawback, of course, is that it will radiate and the open end is at a
relatively high voltage.

I personally think that calling these wires a "counterpoise" is a little
misleading. They are technically a "driven ground system." Being in the
near field of the antenna, they absorb power and develop voltages and
currents accordingly. They are not intended to serve as ground current
collectors like radials on a vertical or to provide much of a "ground" for
unbalanced antennas, such as end-fed wires, to work against. They do, to a
degree, but their main function is to be driven to zero voltage at one end
and maximum voltage at the other, and thereby to place the shack equipment
at or near zero r-f volts.

One other comment: in most cases this is a much more effective way to
"ground" a station than attempting a connection to some sort of earth
ground. A pipie driven a few feet into the earth does not equal an "earth
ground" and any wire from the rig to that pipe has an impedance that cause
more problems that it is intended to resolve.

A true counterpoise should be much closer to resonance at the operating
frequency to perform its function well. But by now, we are talking about
"to-may-to" and "to-mah-to" . . .  <:}

73/72/oo, George W5YR - the Yellow Rose of Texas

+++++++++++++++++
Reply-To: "Don Wilhelm" <w3fpr at peoplepc.com>
From: "Don Wilhelm" <w3fpr at peoplepc.com>
To: "Lloyd Lachow" <llachow at yahoo.com>, <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] How to hook up a longwire to a K1
Date: Thu, 2 May 2002 18:23:08 -0400

I would sugest using a BNC female to PL259 male adapter - also a bannana
plug.  The bannana plug fits nicely into the center of the PL259 and
provides the connection point for the antenna wire.
In case the adapter projection from the back is a bother to you, add an
angle adapter to your 'wants' list.

73,
Don W3FPR

----- Original Message -----
From: "Lloyd Lachow" <llachow at yahoo.com>
To: <elecraft at mailman.qth.net>
Sent: Thursday, May 02, 2002 3:47 PM
Subject: [Elecraft] How to hook up a longwire to a K1


> I believe I'm on the verge of acquiring a K1, and
> beginning to live the dream. I'm not familiar with the
> little nubbin on the back, where the antenna goes. I'm
> using a 90' endfed longwire; what do I need to hook it
> up to this jewel? Thanks!

++++++++++++++++
From: "Sandy, W5TVW" <ebjr at i-55.com>
To: "Lloyd Lachow" <llachow at yahoo.com>, <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] How to hook up a longwire to a K1
Date: Thu, 2 May 2002 18:00:58 -0500

I assume you have the KAT1 option installed ?  The best connection medium available
is an adapter made by Pomona Electronics, Cat nr. 1296.  It adapts the BNC connector
on the set to two banding posts/banana jacks which is VERY versatile and compact in
the
field.
I have also found that a homemade small "Balun" constructed from a small
3/4" ferrite core using twin "speaker wire" for the bifilar winding  works very
well with high impedance or balanced loads.  I mounted the balun in a small
"project box" from Radio Shack, input/output binding posts mounted on each end
of the box.  See any ARRL Handbook for 4:1 balun winding details.
73,
Sandy W5TVW
----- Original Message -----
From: "Lloyd Lachow" <llachow at yahoo.com>
To: <elecraft at mailman.qth.net>
Sent: Thursday, May 02, 2002 2:47 PM
Subject: [Elecraft] How to hook up a longwire to a K1

+++++++++++++++++++
From: "Dan Allen" <dlajr at bellsouth.net>
To: "Philip Westover" <philathillview at worldnet.att.net>,
        <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] Oh Ye of Little Faith - Random Wire Ant. for K1
Date: Wed, 21 Aug 2002 01:33:33 -0400

About 1987, I went to a hardware store near my home and bought a 100 foot
spool of stranded automotive hookup wire with black insulation.  I ran it
out of an upstairs bathroom window to a large pine tree.  I had about 10
feet left over, so I say I have a 90 foot random wire antenna.  I have used
it with both an MFJ Versa-Tuner II and an SGC-230 automatic antenna tuner.
I have used it with a Collins KWM-2, an ICOM-706, an MFJ QRP Cub, and with
my K2.  I have used it on 160 through 10 meters.  I routinely work Eastern
Europe, Western Europe, South America, Central America, the Caribbean, and
Canada.  I have also worked Africa, Russia and Hawaii.  The antenna is
absolutely invisible from the street.  Most of my neighbors do not even know
I am a ham.  I am *really* sold on random wire antennas!

Dan Allen
KB4ZVM
S/N 1757

----- Original Message -----
From: "Philip Westover" <philathillview at worldnet.att.net>
To: <elecraft at mailman.qth.net>
Sent: Tuesday, August 20, 2002 11:49 PM
Subject: [Elecraft] Oh Ye of Little Faith - Random Wire Ant. for K1


> Well, after much procrastination, I decided to try an
> antenna recommended by Wayne for my K1 (has a KAT1
> installed).  I ran a 35 foot wire straight from the BNC
> connector out the back, with about a 25 foot ground wire,
> also straight out the BNC connector.  With a quick ATU
> match, I proceeded to get several multi-state contacts while
> sitting on the grass in my backyard!  I guess when "The Man"
> says he optimized the KAT1 for such antennas, I guess I
> should have a little more faith.  From now on, forget about
> having to find all those trees in the right places for my
> dipole, and forget about that lossy feedline!  Amen,
> Brother!
>
> Well, I'm a convert!  Tomorrow (8/21/02) through Saturday
> (8/24/02), I'll be with my Boy Scout Troop on a Oregon
> Willamette River canoe trek, operating each night around
> 8:00 p.m. Pacific Daylight Time (0300 UTC), first on 20m
> (14040 or so), then on 40m (7040 +- 5).  I'll be using my
> new "easy-to-set-up" antenna, and I hope to make some
> contacts with fellow K1 and K2 owners.
>
> And, thanks again, Wayne, for all you do to make amateur
> radio a great hobby!
>
> 73,
> Phil, WA7URV
> K1 #220
> K2 #2690

++++++++++++++++++
From: "Sandy, W5TVW" <ebjr at i-55.com>
To: "Niel Wiegand" <w0vlz at arrl.net>, <elecraft at mailman.qth.net>
Cc: <philathillview at worldnet.att.net>
Subject: Re: [Elecraft] Oh Ye of Little Faith - Random Wire Ant. for K1
Date: Wed, 21 Aug 2002 15:36:45 -0500

Motion seconded here!  I have been carrying routinely in my portable
QRP antenna kit (housed in a belly or waist pack) several lengths of 33'
and 66' hookup wire hanks, each terminated in a banana plug, one Pomona
BNC to binding post adapter (beware of the cheap ones at Radio Shack!
spend the money on a really GOOD one!), one spool of nylon seine line
(about 1/16" diameter), several "teardrop" or "bell" sinkers 1/2 and 1 ounce
for throwing over limbs, up in trees etc.(paint them bright day glo orange
do they are easy to spot hanging or on the ground or grass!)  I use
one sloping wire for a radiator and several laid on the ground for 
a counterpoise.  A "randowm wire" antenna will perform 
MUCH BETTER with a counterpoise or radial system, no less than 
2 or three or more.  
WIRE?  I use #24 guage stranded "Mil Spec" type insulated hookup wire.
Large (1000') reels can be bought at the larger hamfests very cheaply.
Last batch I got was at Dayton for about $3-4 a reel!  The "Mil-Spec" wire
has a lot of strands and is very flexible, unlike the poor quality stuff you get
at Radio Shack.
INSULATORS?  You already have a roll of Nylon line!  Make them from small 
loops using about 4-6 inches of the nylon line.  Strong and disposable.
If you MUST have "proper" insulators, make them from 1/8" plexaglas
or something similar available in small odd quantities in the "scrap bin"
at Cadillac Plastics stores.  "Sign shops" sometimes have oddss and ends
of plastic to serve the same purpose.
73 to all and good portable QRPing!
Sandy W5TVW
K1 #1178

++++++++++++++
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] Random Wire???
From: "Steve Lawrence" <Steve.Lawrence at ITWFEG.COM>
Date: Thu, 9 Jan 2003 10:22:21 -0500

In Alan Chester's (G3CCB) (SK) article "Taming the End-Fed Antenna" (page 
118 of the "Antenna File" published by RSGB) Mr. Chester rationalized that 
there might be some impedance friendly length of wire usable for an 
end-fed antenna that doesn't present a tough to tune, high impedance load 
on several bands.  The "undesirable" length being on/near 1/2 wavelength 
or multiple thereof on the desired operating frequency.  He concludes a 
length of 1/8 - 3/8 or 5/8 - 7/8 wavelength (or multiples thereof) 
represents the desirable targets to reduce impedance and therefore 
improves the ease of devising a suitable match.

Mr. Chester proceeds to plot the length of wire, staying way from the 3/8 
- 5/8 wavelengths (or multiples thereof) for the bands from 160M - 10M. 
The resulting plot is examined for lengths that fall in the "desirable" 
range for as many bands possible.

>From these plots, he looks at several end-fed wire lengths:  26.5m, 15.0m, 
and 10.0m.  Conclusion?  The 26.5m wire appears suitable for 160 - 10M; 
the 15.0m length for 80, 40, 20, 17, 15, 12, and 10M;  and the 10.0m 
length for 80, 40, 30, 17, 15, 12, and 10M.

While I don't (yet) have experience with these results, the 
rationalization appears sound.  I'm planning to conduct some experiments 
this spring!

Steve
AA8AF

++++++++++++++
From: "David Gropper" <dmg at bossig.com>
To: "Guy Olinger, K2AV" <olinger at bellsouth.net>,
        "Leonard, David" <david.leonard at spcorp.com>,
        <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] Feeding a Random length wire with the KAT2 ATU
Date: Thu, 3 Apr 2003 21:28:03 -0800

Adding my $0.02 worth...

There is a very nice table in Les Moxons' book "HF Antennas
for All Locations".
It is Fig 4.37 and shows lengths that are non-resonant
dependant on the bands you want for your basic Inverted-L
antenna assuming you don't mind radiation from the feeder !!.

For the Non-WARC bands, other good choices are 58, 76, 96, and
109 feet. This assumes you are using capacitive matching
which, of  course the KAT1/2 tuners can easily handle. (Thanks
Elecraft chappies!)

If using a "Pi" type tuner (C-L-C) then resonant lengths can
be used - even an overall length of 133 ft, as an inverted-L,
is capable of some good contacts on 160M even as low as 20 ft
off the ground. Not the best but it will give you some
contacts. (Personal experience!!)

Usual disclaimers....


Dave KK7SS
K2 #3003

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