On 2/6/2011 1:25 PM, dave wrote:
[...]

- It's the new one. Well, yes, that's right, an inverted L. The
- vertical is about 30 feet, the horizontal about 60. Oriented
nearly
- north-south (not checked with a compass), far end is south.
Guatemala
- is off the forward left side if you looking the direction the
antenna
- is aimed.

BpnJ,

'The Antenna's Size' is "The Antenna's Size" : A Fixed Point
-how-ever- as the Frequency Varies for 500 kHs to 1 MHz
to 2 MHz to 4 MHz to 8 MHz to 16 MHz to 32 MHz
the Propagation Characteristics of the Antenna ~change~
So having the Vertical-Up-Leg as your Starting Reference
Point and your Far-End as your End-Point should/would
allow you to have an Idea {Hunch} about the Receiving
Properties of your Fixed Size Antenna on any given
High {Shortwave} Frequency [HF].
.
.
- How much does the 30 vertical do for you, other than
- collect vertically polarized QRM?

How better to get to your 60 Foot Out-Horizontal-Arm
1/3rd Omni-Direction Vertical Antenna
+plus+
2/3rds Off-the-Sides Horizontal Antenna*
-and- 45 Degree Out-from-the-Sides Horizontal Antenna*
-and- Off-the-End Horizontal Antenna*
* Depending on the Frequency
.
- The only reason, really, I built it this way was to
- allow the 9:1 antenna unun to be mounted near
- ground (the ground is not in place yet, but will be
- soon). Otherwise, I would have put the whole thing
- up high, or possibly sloped with the unun end down.

Close to the Ground is 'good'.
.
- This morning (1800z onward), the VOA relays from
- MDG and BOT (Africa) on 16 and 19 meters were
- coming in almost like locals.
-
- Bruce

Strong Signals and less noise is good too ) ~ RHF
.
.

Actually, isn't the directionality of a wire along it's axis? That's
how the PAR end-fed SWL antenna is, according to Dale...

That is a very complicated subject. Usually a wire close to the
ground has a pattern between a kaleidoscope and a butterfly on acid.
Seriously, like a butterfly more often than not, with various lobes
and nulls depending on the frequency.



Bruce:

I have EZNEC, which is a very good antenna modeling program. I
modeled your antenna for various frequencies and created a fairly
readable 3D plot of its pattern on various frequencies. In each
case, the horizontal wire points in the opposite direction from the
Y axis shown in the plots:

1 MHz:
http://liberty.3950.net/Jensen%201.PNG

5 MHz:
http://liberty.3950.net/Jensen%205.PNG

6 MHz:
http://liberty.3950.net/Jensen%206.PNG

7 MHz:
http://liberty.3950.net/Jensen%207.PNG

10 MHz:
http://liberty.3950.net/Jensen%2010.PNG

15 MHz:
http://liberty.3950.net/Jensen%2015.PNG

17 MHz:
http://liberty.3950.net/Jensen%2017.PNG

22 MHz:
http://liberty.3950.net/Jensen%2022.PNG


With all good wishes,



Kevin, WB4AIO.
--
http://nationalvanguard.org/
http://kevinalfredstrom.com/

On Feb 6, 9:10*am, bpnjensen wrote:
On Feb 6, 2:32*am, RHF wrote:
.



- Otherwise, I would have put the whole thing up high,
- or possibly sloped with the unun end down.

- - Better would be to have the Feed-in-Line running
- - 4"~6" below the Ground directly under the Wire
- - Antenna Element all the way out to the UnUn and
- - Ground Rod; with the Antenna Element Sloping-Up
- - back over the 'lay' of the Feed-in-Line.
- -
- - ~ RHF

- Why is the alignment important?

BpnJ : ? Alignment = Lay-Out = By-Design !

Many Types and Configurations of "Sloper" Antennas
http://groups.google.com/group/rec.r...7a96ab218b8103

NOTE : The "Sloper" Antenna normally needs a better
more consistent Earthen Ground under it than an
Elevated Horizontal "Flat" Wire Antenna.
* The "Sloper" Antenna is more of a 'Ground Reflective'
Aerial
* * The Elevated Horizontal "Flat" Wire Antenna is more
of a 'Free Space' Aerial. {Higher Up and Away from the
Earth 'Ground'}

On 02/06/2011 01:49 PM, RHF wrote:
On Feb 6, 6:09 am, wrote:


Real slopers have the feedpoint at the top.


* Most have a High Feed-Point 25~30 Feet and a
Lower End-Point 8~10 Feet {this is to keep the
Lower End-Point 'over-head' and not a Hanging a/o
Tripping Hazard}

Do you know how many volts are at the far end of a dipole when it is fed
100 Watts at resonance?

On Feb 6, 2:52*pm, Kevin Alfred Strom
wrote:
On 2/6/2011 1:25 PM, dave wrote:
[...]











- It's the new one. Well, yes, that's right, an inverted L. The
- vertical is about 30 feet, the horizontal about 60. Oriented
nearly
- north-south (not checked with a compass), far end is south.
Guatemala
- is off the forward left side if you looking the direction the
antenna
- is aimed.

BpnJ,

'The Antenna's Size' is "The Antenna's Size" : A Fixed Point
-how-ever- as the Frequency Varies for 500 kHs to 1 MHz
to 2 MHz to 4 MHz to 8 MHz to 16 MHz to 32 MHz
the Propagation Characteristics of the Antenna ~change~
So having the Vertical-Up-Leg as your Starting Reference
Point and your Far-End as your End-Point should/would
allow you to have an Idea {Hunch} about the Receiving
Properties of your Fixed Size Antenna on any given
High {Shortwave} Frequency [HF].
.
.
- How much does the 30 vertical do for you, other than
- collect vertically polarized QRM?

How better to get to your 60 Foot Out-Horizontal-Arm
1/3rd Omni-Direction Vertical Antenna
+plus+
2/3rds Off-the-Sides Horizontal Antenna*
-and- 45 Degree Out-from-the-Sides Horizontal Antenna*
-and- Off-the-End Horizontal Antenna*
* Depending on the Frequency
.
- The only reason, really, I built it this way was to
- allow the 9:1 antenna unun to be mounted near
- ground (the ground is not in place yet, but will be
- soon). Otherwise, I would have put the whole thing
- up high, or possibly sloped with the unun end down.

Close to the Ground is 'good'.
.
- This morning (1800z onward), the VOA relays from
- MDG and BOT (Africa) on 16 and 19 meters were
- coming in almost like locals.
-
- Bruce

Strong Signals and less noise is good too ) ~ RHF
.
.

Actually, isn't the directionality of a wire along it's axis? That's
how the PAR end-fed SWL antenna is, according to Dale...

That is a very complicated subject. Usually a wire close to the
ground has a pattern between a kaleidoscope and a butterfly on acid.
Seriously, like a butterfly more often than not, with various lobes
and nulls depending on the frequency.

Bruce:

I have EZNEC, which is a very good antenna modeling program. I
modeled your antenna for various frequencies and created a fairly
readable 3D plot of its pattern on various frequencies. In each
case, the horizontal wire points in the opposite direction from the
Y axis shown in the plots:

1 MHz:http://liberty.3950.net/Jensen%201.PNG

5 MHz:http://liberty.3950.net/Jensen%205.PNG

6 MHz:http://liberty.3950.net/Jensen%206.PNG

7 MHz:http://liberty.3950.net/Jensen%207.PNG

10 MHz:http://liberty.3950.net/Jensen%2010.PNG

15 MHz:http://liberty.3950.net/Jensen%2015.PNG

17 MHz:http://liberty.3950.net/Jensen%2017.PNG

22 MHz:http://liberty.3950.net/Jensen%2022.PNG

With all good wishes,

Kevin, WB4AIO.
--http://nationalvanguard.org/http://kevinalfredstrom.com/

Wow! These are amazing! Thanks, Kevin. I am somewhat surprised,
though, by the apparently omnidirectional character (at least
horizontally) on the lower freqs. The higher end looks like a
mathematical nightmare!

One thing notable too, is the lower angle of radiation on the higher
freqs. I wish I could attain those on the lower ones - but the only
way to do that is go higher, I guess.

On 02/06/2011 03:04 PM, RHF wrote:
On Feb 6, 9:10 am, wrote:
On Feb 6, 2:32 am, wrote:
.



- Otherwise, I would have put the whole thing up high,
- or possibly sloped with the unun end down.

- - Better would be to have the Feed-in-Line running
- - 4"~6" below the Ground directly under the Wire
- - Antenna Element all the way out to the UnUn and
- - Ground Rod; with the Antenna Element Sloping-Up
- - back over the 'lay' of the Feed-in-Line.
- -
- - ~ RHF

- Why is the alignment important?

BpnJ : ? Alignment = Lay-Out = By-Design !

Many Types and Configurations of "Sloper" Antennas
http://groups.google.com/group/rec.r...7a96ab218b8103

NOTE : The "Sloper" Antenna normally needs a better
more consistent Earthen Ground under it than an
Elevated Horizontal "Flat" Wire Antenna.
* The "Sloper" Antenna is more of a 'Ground Reflective'
Aerial
* * The Elevated Horizontal "Flat" Wire Antenna is more
of a 'Free Space' Aerial. {Higher Up and Away from the
Earth 'Ground'}
.

The sloper's a vertical and needs a bottom half. Grounds work better 6
feet in the air than 6 inches below the earth. All antennas are dipoles.

On 11-02-06 04:10 PM, dave wrote:
On 02/06/2011 01:49 PM, RHF wrote:
On Feb 6, 6:09 am, wrote:


Real slopers have the feedpoint at the top.


* Most have a High Feed-Point 25~30 Feet and a
Lower End-Point 8~10 Feet {this is to keep the
Lower End-Point 'over-head' and not a Hanging a/o
Tripping Hazard}

Do you know how many volts are at the far end of a dipole when it is fed
100 Watts at resonance?


well, if it's at the maximum point of the sine wave, it should be p =
e^2 / r, or e^2 = 100*75, or e = root (7500) = 87 volts

I'm now wondering where the screw up is....I'm assuming a 75 ohm loading.

mike

On Feb 6, 3:10*pm, dave wrote:
On 02/06/2011 01:49 PM, RHF wrote:

On Feb 6, 6:09 am, *wrote:

Real slopers have the feedpoint at the top.

- - * Most have a High Feed-Point 25~30 Feet and a
- - Lower End-Point 8~10 Feet {this is to keep the
- - Lower End-Point 'over-head' and not a Hanging a/o
- - Tripping Hazard}

- Do you know how many volts are at the far end
- of a dipole when it is fed 100 Watts at resonance?

Dave : ? "far end of a dipole" antenna ?

Dave how does that related to a "Sloper" Antennas ?

Many Types and Configurations of "Sloper" Antennas
http://groups.google.com/group/rec.r...7a96ab218b8103

Dave : ? "volts" ? & ? "100 Watts" ?

Generally for Receive Only Shortwave Radio Listening
[SWL] Antennas Transmitting {powered} Parameters
are not a practical consideration. =KASAP=

On 2/6/2011 6:14 PM, bpnjensen wrote:
[...]

Bruce:

I have EZNEC, which is a very good antenna modeling program. I
modeled your antenna for various frequencies and created a fairly
readable 3D plot of its pattern on various frequencies. In each
case, the horizontal wire points in the opposite direction from the
Y axis shown in the plots:

1 MHz:http://liberty.3950.net/Jensen%201.PNG

5 MHz:http://liberty.3950.net/Jensen%205.PNG

6 MHz:http://liberty.3950.net/Jensen%206.PNG

7 MHz:http://liberty.3950.net/Jensen%207.PNG

10 MHz:http://liberty.3950.net/Jensen%2010.PNG

15 MHz:http://liberty.3950.net/Jensen%2015.PNG

17 MHz:http://liberty.3950.net/Jensen%2017.PNG

22 MHz:http://liberty.3950.net/Jensen%2022.PNG

With all good wishes,

Kevin, WB4AIO.
--http://nationalvanguard.org/http://kevinalfredstrom.com/

Wow! These are amazing! Thanks, Kevin. I am somewhat surprised,
though, by the apparently omnidirectional character (at least
horizontally) on the lower freqs.



You're welcome.

Well, the omni pattern an octave or so around the quarter wave
resonance isn't too surprising, really, if you think about it.

The vertical section gives omnidirectionality in the horizontal
plane, but a null directly overhead. The horizontal part fills in
that null and is basically elliptical in the horizontal plane. So
they complement each other to produce an almost-omni pattern. Nice
antenna, really. My 150-foot inverted L was one of my favorite
antennas of all time for 75 meter ham use.

You might be able to enhance the low angles with a radial ground
system, but for receiving on the noisier low bands you might not be
able to perceive any improvement beyond higher S-meter readings. A
beverage antenna would give you low angle directivity, as would a
K9AY loop.



The higher end looks like a
mathematical nightmare!


That's the psychedelic butterfly pattern that Dave was talking about.



One thing notable too, is the lower angle of radiation on the higher
freqs. I wish I could attain those on the lower ones - but the only
way to do that is go higher, I guess.


If you want to suppress the high-angle part of the pattern (and make
nearby North American signals and static weaker compared to the
farther DX), going strictly vertical would help. A horizontal
antenna a half wave up has a similar effect (that's up about 100
feet for 60 meters).


Have fun,



Kevin, WB4AIO.
--
http://nationalvanguard.org/
http://kevinalfredstrom.com/

On Feb 5, 3:35*pm, "D. Peter Maus" wrote:

* *You do have a quite a bit of antenna, there. Verify that you've not
got too much. Look for images, indicating overload. A pad may be required..

FWIW, I have found that this new antenna, even before the unun is
grounded, works *extremely* well on almost all bands for elimination
of electrical hash noise with my DX-Ultra and MFJ-1026. I can lop off
4-8 S-Units of hash noise while scarcely touching the desired signal,
leaving otherwise obscured signals either in the clear or almost so.
It has brought otherwise undetectable signals to easy copy. Right
now, I'm wishing I had room for two of them - I could silence 60 and
90 meters background with them.

Maybe I'll take down the DX-Ultra and put up another one of these.
I'd hate to lose the DX-U (it's great on everything 41 meters and up),
but two matched antennae on the MFJ-1026 would work wonders, I think.

Bruce

On 2/8/11 11:06 , bpnjensen wrote:
On Feb 5, 3:35 pm, "D. Peter wrote:

You do have a quite a bit of antenna, there. Verify that you've not
got too much. Look for images, indicating overload. A pad may be required.

FWIW, I have found that this new antenna, even before the unun is
grounded, works *extremely* well on almost all bands for elimination
of electrical hash noise with my DX-Ultra and MFJ-1026. I can lop off
4-8 S-Units of hash noise while scarcely touching the desired signal,
leaving otherwise obscured signals either in the clear or almost so.
It has brought otherwise undetectable signals to easy copy. Right
now, I'm wishing I had room for two of them - I could silence 60 and
90 meters background with them.

Maybe I'll take down the DX-Ultra and put up another one of these.
I'd hate to lose the DX-U (it's great on everything 41 meters and up),
but two matched antennae on the MFJ-1026 would work wonders, I think.

Bruce

Excellent. This is good to hear. Congratulations.