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"random wire" and the KX3 ATU

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n0nuf

"random wire" and the KX3 ATU

Hello everyone.

I've seen a lot of traffic on the "random wire" topic. Does anyone
have a link to a website or an excellent design for a "random wire"
that will at least do all bands 40m up (40-10)? Please drop me an
email if you have any information on a good wire design.

Thanks,
Scott - n0nuf
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Don Butler

Re: "random wire" and the KX3 ATU

Scott ... I suggest that you download the KXAT1 manual from the Elecraft
Website .... pages 9-11 have some great suggestions for random wire antenna
lengths and wire types, etc. I followed those suggestions when I first got
my KX1 ... I think my random wire is about 28 feet long. Using a bnc to
dual binding post adapter with the random wire and a counterpoise I've had
great success with the KX1 on 40M, 30M, and 20M. and now I'm using the
same setup with my KX3, and in addition to 23, 30, and 40 I've also had
success on 17M..

My biggest problem seems to be finding a suitable tree to support the wire
and to avoid getting things in a tangle when I'm setting up... so when I
can I take along my own wire support ... a tripod (which I have as a
keyboard amplifier stand, but is very similar to the tripods sold by
buddipole and yagi in a bag folks)... and a telescoping painter pole that
extends to 16 feet ... with that setup I can get it up about 22 feet in just
a few minutes.

I recently drove up the mountainside near my home and set it up for a couple
hours ... and posted a few pictures here:
http://www.udxa.org/gallery/show_thumbs.php?id=28 ... feel free to check
them out.

It sets up in minutes ... and it works. I personally think the random wire
has an advantage over things like Buddipoles and Mini Yagis because you
don't have to recongifure the antenna every time you want to change bands...

73,
Don, N5LZ

----- Original Message -----
From: "Scott Graham" <[hidden email]>
To: <[hidden email]>
Sent: Wednesday, June 27, 2012 1:15 PM
Subject: [Elecraft] "random wire" and the KX3 ATU

> Hello everyone.
>
> I've seen a lot of traffic on the "random wire" topic. Does anyone
> have a link to a website or an excellent design for a "random wire"
> that will at least do all bands 40m up (40-10)? Please drop me an
> email if you have any information on a good wire design.
>
> Thanks,
> Scott - n0nuf
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

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Mike WA8BXN

Re: "random wire" and the KX3 ATU

In reply to this post by n0nuf

Hi Scott ---

A true random wire antenna is the length of wire you can fit between your
end supports. You insulate the ends, and a wire goes from the near end of
the random wire to the tuner. A ground on the tuner will be useful.
Now, if you want to pick a length for all the wire you will be using (but it
will then not be "random") try to avoid any length that will be a half wave
or multiple of a half wave on any frequency of interest. Here is one web
site that addresses the issue:
http://www.hamuniverse.com/randomwireantennalengths.html

A Google search for random length antenna will reveal many other sources of
information.

73 - Mike WA8BXN

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

From: Scott Graham
Date: 6/27/2012 3:28:52 PM
To: [hidden email]
Subject: [Elecraft] "random wire" and the KX3 ATU

Hello everyone.

I've seen a lot of traffic on the "random wire" topic. Does anyone
have a link to a website or an excellent design for a "random wire"
that will at least do all bands 40m up (40-10)? Please drop me an
email if you have any information on a good wire design.

Thanks,
Scott - n0nuf
______________________________________________________________
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Gary Marklund

Re: "random wire" and the KX3 ATU

I think it was Eric who wrote a bit ago that an 84 foot wire could be matched on 160 to 10 meters. If I select that length for my KX3 kit, will I need a separate Counterpoise for each of these bands?

73
Gary
KJ7RT

Sent from my iPad

On Jun 27, 2012, at 13:10, Mike WA8BXN <[hidden email]> wrote:

> Hi Scott ---
>
> A true random wire antenna is the length of wire you can fit between your
> end supports. You insulate the ends, and a wire goes from the near end of
> the random wire to the tuner. A ground on the tuner will be useful.
> Now, if you want to pick a length for all the wire you will be using (but it
> will then not be "random") try to avoid any length that will be a half wave
> or multiple of a half wave on any frequency of interest. Here is one web
> site that addresses the issue:
> http://www.hamuniverse.com/randomwireantennalengths.html
>
> A Google search for random length antenna will reveal many other sources of
> information.
>
> 73 - Mike WA8BXN
>
>
>
>
>
> -------Original Message-------
>
> From: Scott Graham
> Date: 6/27/2012 3:28:52 PM
> To: [hidden email]
> Subject: [Elecraft] "random wire" and the KX3 ATU
>
> Hello everyone.
>
> I've seen a lot of traffic on the "random wire" topic. Does anyone
> have a link to a website or an excellent design for a "random wire"
> that will at least do all bands 40m up (40-10)? Please drop me an
> email if you have any information on a good wire design.
>
> Thanks,
> Scott - n0nuf
> ______________________________________________________________
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

Jim Brown-10

Re: "random wire" and the KX3 ATU

On 6/27/2012 4:33 PM, Gary Marklund wrote:
> will I need a separate Counterpoise for each of these bands?

No, but in general, more is better, and it's better if it's not laying
on the ground. It simply becomes the other half of the antenna that
you're loading -- think of it as providing a return for the current.
When someone said "you want a ground on the KX3," what he SHOULD have
said is that you need some sort of return for the antenna current.
Radials are one form of return, a counterpoise is another. A
counterpoise is simply another conductor connected to the chassis of the
antenna tuner (or transmitter).

73, Jim K9YC
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Don Wilhelm-4

Re: "random wire" and the KX3 ATU

In reply to this post by Gary Marklund

Gary and all,

That length is close to the W3EDP antenna length - as I recall, it is 86
feet for the radiator and 17 feet for the counterpoise wire. 80 through
10 meters is good, and the KX3 tuner will match it easily.

73,
Don W3FPR

On 6/27/2012 7:33 PM, Gary Marklund wrote:
> I think it was Eric who wrote a bit ago that an 84 foot wire could be matched on 160 to 10 meters. If I select that length for my KX3 kit, will I need a separate Counterpoise for each of these bands?
>
> 73
> Gary
> KJ7RT
>

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Tony Estep

Re: "random wire" and the KX3 ATU

In reply to this post by n0nuf

On Wed, Jun 27, 2012 at 2:15 PM, Scott Graham <[hidden email]> wrote:

> ...an excellent design for a "random wire"...?
>

=======
Scott, for years my main shack antenna was a wire running out the window to
a tree in my yard, a total of 200 feet. It is fed by a unun which in turn
is fed by about 25' of coax. The unun is on the windowsill of the
second-floor shack, and the antenna wire comes right inside.

The cold side of the unun is connected to a 4-wire counterpoise that has
lengths corresponding roughly to 1/4 wave on 40, 20 and 10 meters. This
mess runs out the window and is arrayed on the garage roof.

Between the unun and the radio is a common mode choke that I got from
radioworks.com. I have zero problem with RF in the shack with 100W. When I
went to 500W I had to tweak the counterpoise a few times to get RF down to
zero on 12 Meters. The tuner in the K3 matches this antenna to 1.2:1 or
better on all bands 80, 40, 30, 20, 17, 15, 12 and 10. I have worked 280
countries with this antenna. Its main drawback is that it is noisy on
reception. When I finally got a hexbeam (a compact 2-el yagi) mounted on my
chimney at 20', it was an improvement not so much for the modest amount of
gain it offered, but for the reduced noise.

This is the second antenna setup I have had along these lines. Both have
been extremely successful, especially when you consider the cost (just a
few bucks), the unobtrusiveness, the ease of setup, and the ease of
maintenance, tuning etc. If you try one and have questions, email me. Best
of luck!

73, Tony KT0NY

--
http://www.isb.edu/faculty/facultydir.aspx?ddlFaculty=352
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Gary Marklund

Re: "random wire" and the KX3 ATU

In reply to this post by Don Wilhelm-4

Thanks, Don. I have a 400' reel of The Wireman's #543 to cut up, so this looks like a good place to start. Should be east to launch as well.

73
Gary KJ7RT

Sent from my iPad

On Jun 27, 2012, at 17:07, Don Wilhelm <[hidden email]> wrote:

> Gary and all,
>
> That length is close to the W3EDP antenna length - as I recall, it is 86 feet for the radiator and 17 feet for the counterpoise wire. 80 through 10 meters is good, and the KX3 tuner will match it easily.
>
> 73,
> Don W3FPR
>
> On 6/27/2012 7:33 PM, Gary Marklund wrote:
>> I think it was Eric who wrote a bit ago that an 84 foot wire could be matched on 160 to 10 meters. If I select that length for my KX3 kit, will I need a separate Counterpoise for each of these bands?
>>
>> 73
>> Gary
>> KJ7RT
>>
>

wayne burdick

Re: "random wire" and the KX3 ATU

Administrator

In reply to this post by Gary Marklund

Gary Marklund wrote:

> I think it was Eric who wrote a bit ago that an 84 foot wire could
> be matched on 160 to 10 meters.

At Field Day, just playing around, we used the KXAT3 to match a 20-
meter 2-element beam (fed with coax) on 80-6 meters. Not efficient on
any bands but 30/20/17, but nice to know you can do it in a pinch.

W

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Mike Markowski-2

Re: "random wire" and the KX3 ATU

In reply to this post by Mike WA8BXN

Thanks, Mike. I noticed Jack VE3EED made his calculations using the band
center. Out of curiosity I just write a little C program that uses band edges
and converts them to half wavelengths. I plotted the overlapping "red zones"
and, if I didn't make a mistake, came up with slightly different safe lengths.
The graph and C code are at

http://udel.edu/~mm/ham/randomWire/

Let me know if you spot errors in the code! (I didn't include 60m, by the way.)

73,
Mike ab3ap

On 06/27/2012 04:10 PM, Mike WA8BXN wrote:
> [...] to avoid any length that will be a half wave
> or multiple of a half wave on any frequency of interest. Here is one web
> site that addresses the issue:
> http://www.hamuniverse.com/randomwireantennalengths.html
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Michael Babineau-2

Re: "random wire" and the KX3 ATU

In reply to this post by n0nuf

In fact what you can do is just make the first 17 feet of the antenna (including counterpoise) out of ladder line or even twin lead so that
it is a zepp fed W3EDP. This is what I use as my low-band antenna at home and my backup antenna at the cottage. Through a 4:1
balun I am able to get a good match on 160m through 10m with the internal tuner in my K2 and my LDG auto-tuner.
It works .. I even made a few 160m QSOs with it running 5W on CW during field day. I find that it is easiest to erect as an inverted-L.

Michael VE3WMB

>From: Don Wilhelm <[hidden email]>
>Date: June 27, 2012 8:07:22 PM EDT
>To: Gary Marklund <[hidden email]>
>Cc: Scott Graham <[hidden email]>, "<[hidden email]>" <[hidden email]>
>Subject: Re: [Elecraft] "random wire" and the KX3 ATU
>Reply-To: [hidden email]

>Gary and all,

>That length is close to the W3EDP antenna length - as I recall, it is 86 feet for the radiator and 17 feet for the counterpoise wire. 80 through 10 meters is good, and the KX3 tuner will match it easily.

>73,
>Don W3FPR
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Steve KC8QVO

Re: "random wire" and the KX3 ATU

In reply to this post by Don Butler

I know this is an older topic but I figured I would post back with some results. I made up a random wire and counterpoise that are 28' each exactly as Don mentions - with the BNC-binding post adapter too. This works out pretty well on 40. I haven't tried the other bands but it seems like it will work according to Don.

One trick I can offer is to elevate the radiator and counterpoise, don't just lay the counterpoise on the ground.

Also, tuning was touchy on 40 but the KX3 tuner didn't have any issues with it, I just moved up the band a bit and re-tuned.

Steve, KC8QVO

Don Butler wrote

I think my random wire is about 28 feet long. Using a bnc to
dual binding post adapter with the random wire and a counterpoise I've had
great success with the KX1 on 40M, 30M, and 20M. and now I'm using the
same setup with my KX3, and in addition to 20, 30, and 40 I've also had
success on 17M..

----- Original Message -----
From: "Scott Graham" <[hidden email]>
To: <[hidden email]>
Sent: Wednesday, June 27, 2012 1:15 PM
Subject: [Elecraft] "random wire" and the KX3 ATU

> I've seen a lot of traffic on the "random wire" topic. Does anyone
> have a link to a website or an excellent design for a "random wire"
> that will at least do all bands 40m up (40-10)?