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80 Meter Verticals

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Edward A. Dauer

80 Meter Verticals

A question that’s admittedly a bit OT – though if I need a pretext, the rig to be used is a K3 . . .

I have been reading through the usual texts about vertical antennas for 80 meters, to replace the half wave dipole I now have and the Vee I had but didn’t like. But I have not yet found the answer to one question I am thinking about: The advantages or disadvantages of an inverted L compared to other variations of the top-loaded vertical.

Assume a 40-foot ground-mounted vertical section made with wire running up a fiberglass mast. There could be a remote tuner or balun at the base if it’s needed. The top of the vertical section would be guyed with four lines more or less parallel to the earth extending from the top tip of the vertical section to four suitably located trees. That physical configuration offers three kinds of options.

One is an inverted L. One of the four guy lines would be a wire making the L and long enough to have the overall antenna resonate, with nonconductive line from there to the tree. The other three guy lines would be nonconductive for their entire length.

Another would be the classic top-loaded “T” vertical. Two opposing guy lines would be equal-length wire out far enough to achieve resonance, with the other two nonconductive for their entire length.

A third would be something closer to a capacity hat. All four of the guy lines would start at the tip as wires, of equal length and just long enough to effect resonance, with nonconductive rope from there to each of the four trees. This variation might also have a square loop connecting the distal ends of the four top wires.

If the goal is to have the highest efficiency and the lowest net radiation angle, and if the height of the vertical section is fixed and the radial system is the same for each choice, does it matter which of those three or four options is chosen? And if it does, how come?

Thanks in advance for any lessons offered . . .

Ted, KN1CBR

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Don Wilhelm

Re: 80 Meter Verticals

Ted,

The inverted L will have some horizontally polarized radiation. The
other top loaded verticals should have only vertically polarized
radiation - assuming that the top loading is symmetrical, whether that
be a capacity hat or a T wire.

In general, the vertically polarized radiation will be at a lower angle
than horizontally polarized, but that all depends on the ground
conductivity and your radial system. A radial system of 64 radials is
good if your ground conductivity is decent, but if you are in an area
where ground conductivity is poor, you may have better luck with
horizontal antennas or an inverted Vee - the higher the better.

So the answer is "it all depends". If you do not have a wonderful
ground screen, a vertical may perform worse than a horizontal antenna
because a lot of your RF goes into "heating the worms".

73,
Don W3FPR

On 2/27/2017 6:13 PM, Dauer, Edward wrote:

> A question that’s admittedly a bit OT – though if I need a pretext, the rig to be used is a K3 . . .
>
> I have been reading through the usual texts about vertical antennas for 80 meters, to replace the half wave dipole I now have and the Vee I had but didn’t like. But I have not yet found the answer to one question I am thinking about: The advantages or disadvantages of an inverted L compared to other variations of the top-loaded vertical.
>
> Assume a 40-foot ground-mounted vertical section made with wire running up a fiberglass mast. There could be a remote tuner or balun at the base if it’s needed. The top of the vertical section would be guyed with four lines more or less parallel to the earth extending from the top tip of the vertical section to four suitably located trees. That physical configuration offers three kinds of options.
>
> One is an inverted L. One of the four guy lines would be a wire making the L and long enough to have the overall antenna resonate, with nonconductive line from there to the tree. The other three guy lines would be nonconductive for their entire length.
>
> Another would be the classic top-loaded “T” vertical. Two opposing guy lines would be equal-length wire out far enough to achieve resonance, with the other two nonconductive for their entire length.
>
> A third would be something closer to a capacity hat. All four of the guy lines would start at the tip as wires, of equal length and just long enough to effect resonance, with nonconductive rope from there to each of the four trees. This variation might also have a square loop connecting the distal ends of the four top wires.
>
> If the goal is to have the highest efficiency and the lowest net radiation angle, and if the height of the vertical section is fixed and the radial system is the same for each choice, does it matter which of those three or four options is chosen? And if it does, how come?
>

Irma & Linas(LY2H)

Re: 80 Meter Verticals

Ted,

I would recommend very much the site of DJ0IP for tonns of brilliant ideas
on really working antennas. And also a great article of N6LF in QST March,
2010 on radials. You don't need to have 64 or 164 or a chicken mash all
over the field to get the very eficient antenna working DX. 16 is enough.
Based on these excellent sources, I have used myself with great success the
vertical on 80/40 on the 18m Spider mast with the 16 rqdials 12 m long
each. The other time , in the CQWW CW contest, I had no chance to erect the
18m Spider pole due to cold wx condx, so I put up a modernized 43ft
vertical S9 ( a fiberglass pole , actually with the 43 ft of wire inside).
Modernization has come just to adding some 6 more meters of wire to the end
of 43 footter ( making 1/4 waveln. on 80) plus a coax trap and some 20m
more of wire after it ( getting 1/4 waveln. on 160). So I had a Inverted L
with the 14m vertical part and some 26m with a trap horizontal part (
sloping down really to a 4m pole ). The same 16 12m radials stayed due to
lack of time to change them into 25 m each which would be better for 160.
Nevertheless this compromise decision brought me a good 220 qsos on 160m
and around 200 on 80, with barefoot K3 trx incl the Japanese and US
stations on 160m which , for me, was a surprisingly good score. No separate
RX antenna. The resonance was very easy to tune to with the help of the
antenna analyser Youkit FG-01.

It would have been best if I could do this trap combo on a Spider mast with
18m vertical and with 16 radials of 25m long. I will try this this coming
spring, weather permitting.

Wish you good luck and lots of fun with practical experimentation in the
field!

73! Linas LY2H

On 2017 vas. 28, an at 01:45 Don Wilhelm <[hidden email]> wrote:

> Ted,
>
> The inverted L will have some horizontally polarized radiation. The
> other top loaded verticals should have only vertically polarized
> radiation - assuming that the top loading is symmetrical, whether that
> be a capacity hat or a T wire.
>
> In general, the vertically polarized radiation will be at a lower angle
> than horizontally polarized, but that all depends on the ground
> conductivity and your radial system. A radial system of 64 radials is
> good if your ground conductivity is decent, but if you are in an area
> where ground conductivity is poor, you may have better luck with
> horizontal antennas or an inverted Vee - the higher the better.
>
> So the answer is "it all depends". If you do not have a wonderful
> ground screen, a vertical may perform worse than a horizontal antenna
> because a lot of your RF goes into "heating the worms".
>
> 73,
> Don W3FPR
>
> On 2/27/2017 6:13 PM, Dauer, Edward wrote:
> > A question that’s admittedly a bit OT – though if I need a pretext, the
> rig to be used is a K3 . . .
> >
> > I have been reading through the usual texts about vertical antennas for
> 80 meters, to replace the half wave dipole I now have and the Vee I had but
> didn’t like. But I have not yet found the answer to one question I am
> thinking about: The advantages or disadvantages of an inverted L compared
> to other variations of the top-loaded vertical.
> >
> > Assume a 40-foot ground-mounted vertical section made with wire running
> up a fiberglass mast. There could be a remote tuner or balun at the base
> if it’s needed. The top of the vertical section would be guyed with four
> lines more or less parallel to the earth extending from the top tip of the
> vertical section to four suitably located trees. That physical
> configuration offers three kinds of options.
> >
> > One is an inverted L. One of the four guy lines would be a wire making
> the L and long enough to have the overall antenna resonate, with
> nonconductive line from there to the tree. The other three guy lines would
> be nonconductive for their entire length.
> >
> > Another would be the classic top-loaded “T” vertical. Two opposing guy
> lines would be equal-length wire out far enough to achieve resonance, with
> the other two nonconductive for their entire length.
> >
> > A third would be something closer to a capacity hat. All four of the
> guy lines would start at the tip as wires, of equal length and just long
> enough to effect resonance, with nonconductive rope from there to each of
> the four trees. This variation might also have a square loop connecting
> the distal ends of the four top wires.
> >
> > If the goal is to have the highest efficiency and the lowest net
> radiation angle, and if the height of the vertical section is fixed and the
> radial system is the same for each choice, does it matter which of those
> three or four options is chosen? And if it does, how come?
> >
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k6dgw

Re: 80 Meter Verticals

In reply to this post by Don Wilhelm

Verticals are generally an S-unit or maybe 2 noisier on receive than
horizontal antennas unless you are in a very quiet location. A base-fed
1/4 wave [or less] vertical is analogous to a telegraph line with one
wire, using ground as the return. If you can't put in a good ground
system, you'll be disappointed. I have used Inv-L's and Marconi T's
with as few as 2 radials on the ground, and they worked, but that's not
saying much when the alternative was no antenna at all.

Your idea for top loading with the guys will work fine, that's how WWV
loads their antennas and the way many LORAN-C antennas were loaded. My
last 160m inv-L had about 70 ft vertical and the top horizontal was
about 30 ft which is a bit under 1/4 wavelength. The impedance at the
bottom was about 57+j130 ohms which matched the 50 ohm coax nicely with
just a variable cap in series. I was able to get 12 radials out a few
inches under the surface. Worked very good for transmitting, receiving
... not so much. It was pretty noisy.

73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County
On 2/27/2017 3:43 PM, Don Wilhelm wrote:

Jim Brown-10

Re: 80 Meter Verticals

In reply to this post by Don Wilhelm

On Mon,2/27/2017 3:43 PM, Don Wilhelm wrote:
> The inverted L will have some horizontally polarized radiation.

Yes, but not much, because radiation is the result of current, and
current is maximum at the bottom and minimum at the far end of the wire.
And Fred is right on about verticals generally being noisier on RX. But
not always.

I have a Tee vertical for 160M that works well. 100 ft tall.

Ed, the thing to remember about verticals is that they need an effective
counterpoise. That can be anything from radials to a screen to a K2AV
folded counterpoise. AND that verticals are VERY dependent on the
quality of the soil around you.

There are lots of ideals about this stuff on my website. Study the
material about getting on 160M, and divide all the dimensions by 2 for
80M. Then look at my tutorials on verticals vs horizontal antennas.
k9yc.com/publish.htm They are written to answer exactly the questions
you are asking.

73, Jim K9YC
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Vic Rosenthal

Re: 80 Meter Verticals

In reply to this post by Edward A. Dauer

Theoretically the more top loading you have, the higher the radiation resistance and the better the efficiency. So I like the T better than the L.
I used to have an open wire fed doublet which could be switched to T configuration. It was very helpful to switch between horizontal and vertical polarization on 80 meters.
--
Vic 4X6GP

On February 28, 2017 1:13:17 AM GMT+02:00, "Dauer, Edward" <[hidden email]> wrote:

>A question that’s admittedly a bit OT – though if I need a pretext, the
>rig to be used is a K3 . . .
>
>I have been reading through the usual texts about vertical antennas for
>80 meters, to replace the half wave dipole I now have and the Vee I had
>but didn’t like. But I have not yet found the answer to one question I
>am thinking about: The advantages or disadvantages of an inverted L
>compared to other variations of the top-loaded vertical.
>
>Assume a 40-foot ground-mounted vertical section made with wire running
>up a fiberglass mast. There could be a remote tuner or balun at the
>base if it’s needed. The top of the vertical section would be guyed
>with four lines more or less parallel to the earth extending from the
>top tip of the vertical section to four suitably located trees. That
>physical configuration offers three kinds of options.
>
>One is an inverted L. One of the four guy lines would be a wire making
>the L and long enough to have the overall antenna resonate, with
>nonconductive line from there to the tree. The other three guy lines
>would be nonconductive for their entire length.
>
>Another would be the classic top-loaded “T” vertical. Two opposing guy
>lines would be equal-length wire out far enough to achieve resonance,
>with the other two nonconductive for their entire length.
>
>A third would be something closer to a capacity hat. All four of the
>guy lines would start at the tip as wires, of equal length and just
>long enough to effect resonance, with nonconductive rope from there to
>each of the four trees. This variation might also have a square loop
>connecting the distal ends of the four top wires.
>
>If the goal is to have the highest efficiency and the lowest net
>radiation angle, and if the height of the vertical section is fixed and
>the radial system is the same for each choice, does it matter which of
>those three or four options is chosen? And if it does, how come?
>
>Thanks in advance for any lessons offered . . .
>
>Ted, KN1CBR
>
>______________________________________________________________
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>Post: mailto:[hidden email]
>
>This list hosted by: http://www.qsl.net
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Wes Stewart-2

Re: 80 Meter Verticals

In reply to this post by Edward A. Dauer

Ted,

You need to read W7XC's (SK) article in QST Mar 1990, pp 26-30

On 2/27/2017 4:13 PM, Dauer, Edward wrote:

Bill K9YEQ

Re: 80 Meter Verticals

Because?

Have a great day!
Bill J
K9YEQ

________________________________
From: Elecraft <[hidden email]> on behalf of Wes Stewart <[hidden email]>
Sent: Tuesday, February 28, 2017 11:37:13 AM
To: [hidden email]
Subject: Re: [Elecraft] 80 Meter Verticals

Ted,

You need to read W7XC's (SK) article in QST Mar 1990, pp 26-30

On 2/27/2017 4:13 PM, Dauer, Edward wrote:

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Charlie T, K3ICH

Re: 80 Meter Verticals

In reply to this post by Vic Rosenthal

Is there any truth in the theory of making the vertical radiator out of multiple wires such as ladder line and even adding a third wire woven through the ladder sections and fed on one wire? The physical result is three parallel wires but electrically connected so as to form and "up, down and up again" element. This supposedly raises the radiating element impedance relative to the fixed ground loss resistance. The idea I'm told, is that since the ground resistance (loss) is fixed at whatever it is but as the actual radiating element impedance is raised, the antenna becomes more efficient since the ground loss percentage of the overall feed point impedance is lowered. This impedance change happens in much the same way as a folded dipole feed is a higher impedance than a conventional dipole using a single wires.
I saw this written up a few years ago as a means of increasing the overall efficiency of an inverted L for either 160 of 80 M.

I had an "L" made of the smaller ladder line on 160 with only four ¼λ radials on the ground that seemed to work fairly well. My plan was to install elevated radials, but that would have been a LOT of wire around the yard. Something broke on it after a year or so, and I never re-installed it.

73, Charlie k3ICH

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Ron D'Eau Claire
Sent: Tuesday, February 28, 2017 11:08 PM
To: [hidden email]
Subject: Re: [Elecraft] 80 Meter Verticals

One characteristic of a "T", assuming the top wires run in opposite directions and are of equal length, is that radiation from the top wires is highly suppressed because they are fed "in phase" by the vertical section. That means that nearly all radiation is from the vertical section, whereas in an inverted "L" arrangement there is considerable radiation from the horizontal section.

Some ultimate "T" type antennas for H.F. were the very short verticals documented by Jerry Severt (W2FMI, SK) using umbrella-like multiple top hat loading with many "spokes". The QST archives have his articles.

73 Ron AC7AC

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Wes Stewart-2

Re: 80 Meter Verticals

No truth at all.

On 3/1/2017 6:25 AM, Charlie T, K3ICH wrote:
> Is there any truth in the theory of making the vertical radiator out of multiple wires such as ladder line and even adding a third wire woven through the ladder sections and fed on one wire? The physical result is three parallel wires but electrically connected so as to form and "up, down and up again" element. This supposedly raises the radiating element impedance relative to the fixed ground loss resistance. The idea I'm told, is that since the ground resistance (loss) is fixed at whatever it is but as the actual radiating element impedance is raised, the antenna becomes more efficient since the ground loss percentage of the overall feed point impedance is lowered. This impedance change happens in much the same way as a folded dipole feed is a higher impedance than a conventional dipole using a single wires.
> I saw this written up a few years ago as a means of increasing the overall efficiency of an inverted L for either 160 of 80 M.
>
> I had an "L" made of the smaller ladder line on 160 with only four ¼λ radials on the ground that seemed to work fairly well. My plan was to install elevated radials, but that would have been a LOT of wire around the yard. Something broke on it after a year or so, and I never re-installed it.
>
> 73, Charlie k3ICH
>

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Roy Koeppe

Re: 80 Meter Verticals

-----Original Message-----
From: Wes Stewart
Sent: Wednesday, March 01, 2017 8:27 AM
To: [hidden email]
Subject: Re: [Elecraft] 80 Meter Verticals

No truth at all.

Correct -- radiation resistance remains the same or even slightly lower --
lower Q.

73, Roy K6XK

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Wes Stewart-2

Re: 80 Meter Verticals

In reply to this post by Wes Stewart-2

Now that I provided the succinct answer, allow me to provide an in-depth answer.

But rather than me doing it, I will take the easy way out and simply provide a
link to the fine explanation done by Tom, W8JI:

https://www.w8ji.com/radiation_resistance.htm

Wes N7WS

On 3/1/2017 7:27 AM, Wes Stewart wrote:

> No truth at all.
>
> On 3/1/2017 6:25 AM, Charlie T, K3ICH wrote:
>> Is there any truth in the theory of making the vertical radiator out of
>> multiple wires such as ladder line and even adding a third wire woven through
>> the ladder sections and fed on one wire? The physical result is three
>> parallel wires but electrically connected so as to form and "up, down and up
>> again" element. This supposedly raises the radiating element impedance
>> relative to the fixed ground loss resistance. The idea I'm told, is that
>> since the ground resistance (loss) is fixed at whatever it is but as the
>> actual radiating element impedance is raised, the antenna becomes more
>> efficient since the ground loss percentage of the overall feed point
>> impedance is lowered. This impedance change happens in much the same way as
>> a folded dipole feed is a higher impedance than a conventional dipole using a
>> single wires.
>> I saw this written up a few years ago as a means of increasing the overall
>> efficiency of an inverted L for either 160 of 80 M.
>>
>> I had an "L" made of the smaller ladder line on 160 with only four ¼λ radials
>> on the ground that seemed to work fairly well. My plan was to install
>> elevated radials, but that would have been a LOT of wire around the yard.
>> Something broke on it after a year or so, and I never re-installed it.
>>
>> 73, Charlie k3ICH

Bill K9YEQ

Re: 80 Meter Verticals

Wes, thanks for posting this great reference. Certainly turns a bunch of stuff I have read on its ear and will help with my antenna building underway.

73,
Bill
K9YEQ

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Wes Stewart
Sent: Wednesday, March 1, 2017 10:18 AM
To: [hidden email]
Subject: Re: [Elecraft] 80 Meter Verticals

Now that I provided the succinct answer, allow me to provide an in-depth answer.

But rather than me doing it, I will take the easy way out and simply provide a link to the fine explanation done by Tom, W8JI:

https://www.w8ji.com/radiation_resistance.htm

Wes N7WS

On 3/1/2017 7:27 AM, Wes Stewart wrote:

> No truth at all.
>
> On 3/1/2017 6:25 AM, Charlie T, K3ICH wrote:
>> Is there any truth in the theory of making the vertical radiator out
>> of multiple wires such as ladder line and even adding a third wire
>> woven through the ladder sections and fed on one wire? The physical
>> result is three parallel wires but electrically connected so as to form and "up, down and up
>> again" element. This supposedly raises the radiating element impedance
>> relative to the fixed ground loss resistance. The idea I'm told, is
>> that since the ground resistance (loss) is fixed at whatever it is
>> but as the actual radiating element impedance is raised, the antenna
>> becomes more efficient since the ground loss percentage of the
>> overall feed point impedance is lowered. This impedance change
>> happens in much the same way as a folded dipole feed is a higher
>> impedance than a conventional dipole using a single wires.
>> I saw this written up a few years ago as a means of increasing the
>> overall efficiency of an inverted L for either 160 of 80 M.
>>
>> I had an "L" made of the smaller ladder line on 160 with only four ¼λ
>> radials on the ground that seemed to work fairly well. My plan was to
>> install elevated radials, but that would have been a LOT of wire around the yard.
>> Something broke on it after a year or so, and I never re-installed it.
>>
>> 73, Charlie k3ICH

__________

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Jim Brown-10

Re: 80 Meter Verticals

In reply to this post by Charlie T, K3ICH

On Wed,3/1/2017 5:25 AM, Charlie T, K3ICH wrote:
> Is there any truth in the theory of making the vertical radiator out of multiple wires such as ladder line and even adding a third wire woven through the ladder sections and fed on one wire?

Nope. And that's not "theory," that's someone's dumb idea. :)

BUT -- using multiple spaced conductors in parallel and connecting them
at both ends makes the conductor "thicker," which both lengthens it 1-2
percent and broadens the SWR bandwidth. The same thing happens with a
tower as compared to a single wire. The vertical part of my 160M Tee
vertical is a pair of #12 spaced about 9 inches. When I added the second
wire, I observed that my SWR bandwidth approximately doubled.

73, Jim K9YC

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Charlie T, K3ICH

Re: 80 Meter Verticals

In reply to this post by Wes Stewart-2

Well, THAT was certainly an eye-opener.

Thanks to all who commented. I really learned a lot from that discussion.

Thanks, Charlie k3ICH

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Wes Stewart
Sent: Wednesday, March 01, 2017 11:18 AM
To: [hidden email]
Subject: Re: [Elecraft] 80 Meter Verticals

Now that I provided the succinct answer, allow me to provide an in-depth answer.

But rather than me doing it, I will take the easy way out and simply provide a link to the fine explanation done by Tom, W8JI:

https://www.w8ji.com/radiation_resistance.htm

Wes N7WS

On 3/1/2017 7:27 AM, Wes Stewart wrote:

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Eric Swartz - WA6HHQ

Re: 80 Meter Verticals

Administrator

In reply to this post by Jim Brown-10

We're exceeding the OT limit on this topic. While very interesting, lets wrap it
up by end of day today.

73,
Eric
Moderator
/elecraft.com/
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k6dgw

Re: 80 Meter Verticals

In reply to this post by Jim Brown-10

Coupled resonator? I built a C-R antenna for 30, 17, and 12 when we
first got the WARC bands using 300 ohm open-wire line. Only the 30 m
wire was fed. It seemed to work well, on the rare occasions I could
find someone on the bands. The same technique can be used to expand the
BW of an 80 meter antenna although there are some side effects to be
dealt with.

73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 3/1/2017 11:17 AM, Walter Underwood wrote:
> You can also use close-spaced parallel elements that are resonant at slightly different frequencies than the driven element. This is a different way to make a broadband antenna. This design has a name, but it escapes me right now.
>
> wunder
> K6WRU
> Walter Underwood
> CM87wj
> http://observer.wunderwood.org/ (my blog)
>

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Edward R Cole

Re: 80 Meter Verticals

In reply to this post by Edward A. Dauer

I did that on my 630m inverted-L. Obviously 43-feet vertical is very
short on 495-KHz (less than 10% of a quarter wave), so the antenna is
heavily base loaded by a coil plus the 122-foot top section adds a
little capacity. I ran three wires in parallel spaced a foot apart
in the vertical section tied together at both ends with 1/2 inch
copper tube and the top hat is two parallel wires space 2-foot with
another 1/2 inch copper tube at the far end. This lowered the Q
enough to get SWR<2.0 over 5-KHz bandwidth.

I will have to retune to 472-479 KHz when I hang the antenna back up
after repairs as this is the proposed frequencies for a future ham band.

I operate with 100w (1.3w ERP) under the call sign WD2XSH-45 (ARRL
sponsored Experimental License).

73, Ed - KL7UW
http://www.kl7uw.com
Dubus-NA Business mail:
[hidden email]

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Edward R Cole

Re: 80 Meter Verticals

In reply to this post by Edward A. Dauer

Ron and all:

You can use your tower as one leg of a folded monopole. Run a wire
vertical up one side of your tower separate say 6-12 inches from the
wire shorted over to the tower top. Tower stays grounded and your
wire it fed at the bottom near ground but insulated. Coax shield is
tied to tower ground. Depending on tower height you still may need a
tuner to match it. 80m works nice with 60-foot tower. You still
need ground radials like any 1/4 wave vertical. The tower makes a
nice fat element to lower Q.

If you have a mast with HF antennas at top there will be a little
capacitive loading to the resulting vertical.

73, Ed - KL7UW

Date: Wed, 1 Mar 2017 10:41:40 -0800
From: "Ron D'Eau Claire" <[hidden email]>
To: "'Charlie T, K3ICH'" <[hidden email]>,
<[hidden email]>
Subject: Re: [Elecraft] 80 Meter Verticals
Message-ID: <003501d292bb$780e04d0$682a0e70$@biz>
Content-Type: text/plain; charset="utf-8"

John Heys, G3BDQ, in his book "Practical Wire Antennas" describes
"folded monopoles" or "folded Marconi" antennas - essentially 1/2 of
a folded dipole worked against a system of radials. The monopole is
made of two or three wires. Feed is between one wire and the radial
system while the second or third parallel wires are jointed at the
"top" and retur to be connected to the radial system.

A two-wire folded monopole presents a feedpoint impedance of between
80 and 150 ohms. Heys credits W6SAI in his book "Simple Low-Cost Wire
Antennas" (Radio Publications, Inc., 1972) for a version made from
slotted 300 ohm "twin lead". It is in Inverted L configuration for 80
meters: vertical 30 feet (9.1 meters) then sloping 25 feet (7.6
meters) to the top of a 35 ft (10.6 meter) support. To maintain
resonance and compensate for the velocity factor of the twin lead, an
8 ft 3" (2.4 meter) single wire is run from the joined conductors at
the end of the twin lead to the support.

Heys describes a 3-wire version without a bend but sloping at an
angle of 30 degrees or less from vertical at 65 feet (19.8 meters)
centered on 3.6 MHz. Heys' version requires a 60 foot (18.2 meter)
high support although he notes that for 40 meters a 30 foot support
will be adequate. As with the two wire folded monopole all three
wires are connected at the "top" and the feed point is between the
center wire and the radial system. The other two wire ends are
connected directly to the radial system. Heys notes that a spacing of
1 foot is needed to use the common 1/4 wavelength formula of 234/f (mHz).

Heys says that either antenna can be used on its 3rd harmonic.

73, Ron AC7AC

73, Ed - KL7UW
http://www.kl7uw.com
Dubus-NA Business mail:
[hidden email]

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donovanf

Re: 80 Meter Verticals

In reply to this post by Edward R Cole

Hi Ed,

What is your ground system for your 630 meter inverted-L?

Many of us will be ready for a QSO with you with our lowfer
capable K3s when the band is available. I'll use a 1/4 wavelength
inverted-L with 180 ft vertical and 350 feet horizontal using the
radial system for my 160 meter 4-square array (240 radials
125 feet long).

73
Frank
W3LPL

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

From: "Edward R Cole" <[hidden email]>
To: "Elecraft Reflector" <[hidden email]>
Sent: Thursday, March 2, 2017 8:33:27 AM
Subject: Re: [Elecraft] 80 Meter Verticals

I did that on my 630m inverted-L. Obviously 43-feet vertical is very
short on 495-KHz (less than 10% of a quarter wave), so the antenna is
heavily base loaded by a coil plus the 122-foot top section adds a
little capacity. I ran three wires in parallel spaced a foot apart
in the vertical section tied together at both ends with 1/2 inch
copper tube and the top hat is two parallel wires space 2-foot with
another 1/2 inch copper tube at the far end. This lowered the Q
enough to get SWR<2.0 over 5-KHz bandwidth.

I will have to retune to 472-479 KHz when I hang the antenna back up
after repairs as this is the proposed frequencies for a future ham band.

I operate with 100w (1.3w ERP) under the call sign WD2XSH-45 (ARRL
sponsored Experimental License).

73, Ed - KL7UW
http://www.kl7uw.com
Dubus-NA Business mail:
[hidden email]

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