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Old April 17th 08, 02:20 AM posted to rec.radio.shortwave
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Default Modified inverted L ???

Hiya...

I'm assembling all the fixings I need for a new antenna. Now that I'm
committed to an inverted L with my balun ONLY one foot away from the earthen
ground spike...

Given that the horizontal section of an inverted L antenna could work
directionally, would it be good to use two wires at the top of the vertical
section ??? This way you would have one horizontal wire running say north
to south and the second horizontal wire angled at 45 deg to run east and
west ???

Michael


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Old April 17th 08, 03:35 AM posted to rec.radio.shortwave
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Default Modified inverted L ???

Michael wrote:
Hiya...

I'm assembling all the fixings I need for a new antenna. Now that I'm
committed to an inverted L with my balun ONLY one foot away from the earthen
ground spike...

Given that the horizontal section of an inverted L antenna could work
directionally, would it be good to use two wires at the top of the vertical
section ??? This way you would have one horizontal wire running say north
to south and the second horizontal wire angled at 45 deg to run east and
west ???

Michael


The proper way to use two horizontal wires would be in a dipole or 'V'
configuration but that's a completely different antenna design from an
inverted-L. Otherwise there isn't any real benefit of using two
horizontal wire sections 90-deg apart. It might be worse than one wire
under certain conditions. If you keep the horizontal wire relatively
short (30-50/ft) it won't be that directional, except for perhaps the
highest shortwave frequencies.
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Old April 17th 08, 01:58 PM posted to rec.radio.shortwave
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Default Modified inverted L ???

Michael wrote:
Hiya...

I'm assembling all the fixings I need for a new antenna. Now that I'm
committed to an inverted L with my balun ONLY one foot away from the earthen
ground spike...

Given that the horizontal section of an inverted L antenna could work
directionally, would it be good to use two wires at the top of the vertical
section ??? This way you would have one horizontal wire running say north
to south and the second horizontal wire angled at 45 deg to run east and
west ???

Michael


The math is staggering. The concept of random wire includes the hard
fact that at some freqs the antenna works broadside, at others it is end
firing. Height above the ground also affects directionality quite a
bit. If you really want something closer to omni, go with a sloper,
rather than an "L".
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Old April 17th 08, 02:19 PM posted to rec.radio.shortwave
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Default Modified inverted L ???


"Dave" wrote in message
m...
Michael wrote:
Hiya...

I'm assembling all the fixings I need for a new antenna. Now that I'm
committed to an inverted L with my balun ONLY one foot away from the
earthen ground spike...

Given that the horizontal section of an inverted L antenna could work
directionally, would it be good to use two wires at the top of the
vertical section ??? This way you would have one horizontal wire running
say north to south and the second horizontal wire angled at 45 deg to run
east and west ???

Michael

The math is staggering. The concept of random wire includes the hard fact
that at some freqs the antenna works broadside, at others it is end
firing. Height above the ground also affects directionality quite a bit.
If you really want something closer to omni, go with a sloper, rather than
an "L".


Dave, I have a sloping "L" is that any good.

It works fine for me.

Burr's Radio Shack - http://tinyurl.com/3wuscn

Red Mountain, California / Bulacan, Philippines


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Old April 17th 08, 02:49 PM posted to rec.radio.shortwave
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Default Modified inverted L ???

Burr wrote:
"Dave" wrote in message
m...
Michael wrote:
Hiya...

I'm assembling all the fixings I need for a new antenna. Now that I'm
committed to an inverted L with my balun ONLY one foot away from the
earthen ground spike...

Given that the horizontal section of an inverted L antenna could work
directionally, would it be good to use two wires at the top of the
vertical section ??? This way you would have one horizontal wire running
say north to south and the second horizontal wire angled at 45 deg to run
east and west ???

Michael

The math is staggering. The concept of random wire includes the hard fact
that at some freqs the antenna works broadside, at others it is end
firing. Height above the ground also affects directionality quite a bit.
If you really want something closer to omni, go with a sloper, rather than
an "L".


Dave, I have a sloping "L" is that any good.

It works fine for me.

Burr's Radio Shack - http://tinyurl.com/3wuscn

Red Mountain, California / Bulacan, Philippines


Of course. I have a J shaped 150' wire on a 70' X 100' rectangular lot.
I can hear airplanes from 4,000 miles away.


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Old April 18th 08, 01:54 PM posted to rec.radio.shortwave
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Default The Shortwave Radio Listener (SWL) : Sloper Antenna -versus-

RHF wrote:


This is especially true for the Shortwave Listener using a
Ground Rod at Point 'A' with a 9:1 Matching Transformer
and Coax Cable feed-in-line.

What's Missing ? - Point 'B' for the Shortwave Radio Listener
(SWL) who does not have/make a Point 'B' in their backyard
-but- Does have both Points 'A' and 'C' the Sloper Antenna is a
very good 'choice' in Shortwave Radio Listener (SWL) Antennas.

While -IF- a Shortwave Radio Listener (SWL) has/can make all
three Points 'A', 'B' and 'C' in their backyard -then- An Inverted
"L" Antenna is a very good 'choice' in Shortwave Radio Listener
(SWL) Antennas.

Again - When the Shortwave Listener uses a Ground Rod at
Point 'A' with a 9:1 Matching Transformer and Coax Cable
feed-in-line with one or both of these SWL Antenna 'choices'.

???

You still have to keep the unshielded part away from dirty mains
electricity or you will pick up noise.
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Old April 18th 08, 02:50 PM posted to rec.radio.shortwave
RHF RHF is offline
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Default All-Band Sloping Inverted "L" Antenna -by- Rolf Brevig [LA1IC]

Burr - Take a look at this Shortwave (HF) Antenna.

All-Band Sloping Inverted "L" Antenna -by- Rolf Brevig [LA1IC]
http://www.hamuniverse.com/slopinginvl.html
Put that 4:1 balun, a couple of insulators
and some extra wire to good use!
-source- Ham Universe - http://www.hamuniverse.com/
* The Inverted "L" Antenna : How It Works
* "Magic" Wire Lengths
* Non-Metric {Feet} and Metric {Metres} Calculations
* Tuning Procedure for the Inverted Sloping "L" Antenna
for Amateur Radio Operators.

NOTE - This Sloping Inverted "L" Antenna design uses a
a Ground Mounted Matching Transformer and Ground Rod
at the Feed-Point with a Coax Cable feed-in-line.
Implementing the Low Noise Design Concepts that were
popularized -by- John Doty

READ - SWL Longwire + Low Noise Antenna Connection
+ Grounding Is Key To Good Reception
Three Messages to Read -by- John Doty
http://groups.google.com/group/rec.r...bc6a2bf8acc12d
Follow the Links/URLs provided in the Message

? Why ? Use the Sloping Inverted "L" Antenna : It only
requires One above ground level Elevated Support Point.

MOD - For the Shortwave Radio Listener (SWL) making one of
these simple Wire Antennas the only "Modification" would be
to use a 9:1 Matching Transformer {Balun, MLB} for Receive
'Only' : Instead of the Amateur Ham 4:1 Balun cited for used
with a Transmitter.

SIZING - The All-Band Sloping Inverted "L" Antenna for the
Shortwave Radio Listener (SWL)
Basic it is simply a "Random" Wire Length to cover the
'available' Space that you have in your Yard : Going from
the ground* to the Apex {High-Point} of the Antenna and
back to the gorund*.
* Note - A Fence-Top may be used at one or both Ends
instead of the ground for Safety or convenience.

For Those Who - Have-to-Have "Numbers" :
* SHORTY - Small Size Lot - Backyard :
Short-Back-Leg = 17.1 Feet for 22m
Long-Front-Leg = 24.5 Feet for 31m
Total Length ~ 41.6 Feet
Apex ~ 15 Feet**
Ground Foot-Print ~ 30 Feet Tip-to-Tip
* AVERAGE - Medium Size Lot - Backyard :
Short-Back-Leg = 24.5 Feet for 31m
Long-Front-Leg = 38.5 Feet for 49m
Total Length ~ 63.0 Feet
Apex ~ 22 Feet**
Ground Foot-Print ~ 46 Feet Tip-to-Tip
* BIGGIE - Large Size Lot - Backyard :
Short-Back-Leg = 38.5 Feet for 49m
Long-Front-Leg = 59.2 Feet for 75m
Total Length ~ 97.7 Feet
Apex ~ 34 Feet**
Ground Foot-Print ~ 71 Feet Tip-to-Tip

** Note - If you are using a Fence-Top or other Supports :
Instead of the surface of the ground : Then add their Average
Height to the Apex to get the 'corrected' Height of the Apex.

Doing-the-Angles of the Sloping Inverted "L" Antenna :
http://www.lerc.nasa.gov/WWW/K-12/airplane/sincos.html
The Angle of the Apex should be around 90 Degrees; with
the Starting Angle of the Short-Back-Leg at Ground to the
Apex about 60 Degrees; and the Ending Angle at Ground
of the Long-Front-Leg from the Apex to Ground about 30
Degrees.

FWIW - I call this Sloping Inverted "L" Antenna a
Lazy Inverted "L" Antenna because the "L" is too
'Lazy' to Stand Up-Side-Down {Inverted} ) ~ RHF


Be it Sloping or Lazy - It's sort of an 'L' - iane RHF {pomkia}
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Old April 29th 08, 09:44 AM posted to rec.radio.shortwave
RHF RHF is offline
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Default SWL -Newbies- Installing an Inverted "L" Antenna : The Right-Way !

On Apr 18, 12:22*pm, RHF wrote:
On Apr 18, 5:54*am, Dave wrote:


RHF wrote:


This is especially true for the Shortwave Listener using a
Ground Rod at Point 'A' with a 9:1 Matching Transformer
and Coax Cable feed-in-line.


What's Missing ? - Point 'B' for the Shortwave Radio Listener
(SWL) who does not have/make a Point 'B' in their backyard
-but- Does have both Points 'A' and 'C' the Sloper Antenna is a
very good 'choice' in Shortwave Radio Listener (SWL) Antennas.


While -IF- a Shortwave Radio Listener (SWL) has/can make all
three Points 'A', 'B' and 'C' in their backyard -then- AnInverted
"L" Antenna is a very good 'choice' in Shortwave Radio Listener
(SWL) Antennas.


Again - When the Shortwave Listener uses a Ground Rod at
Point 'A' with a 9:1 Matching Transformer and Coax Cable
feed-in-line with one or both of these SWL Antenna 'choices'.


- - ???
- -
- - You still have to keep the unshielded part away
- - from dirty mains electricity or you will pick up noise.

- Dave - TGWOS ~ RHF
-*.

David - That Goes With Out Saying ~ RHF

SWL -Newbies- Installing an Inverted "L" Antenna : The Right-Way !

Wellbrook "Low Noise Antenna" 'design concept' using two
components they manufactu the Universal Magnetic Balun
(UMB) and the Antenna Feed Isolator (Feed-Line-Isolator).
http://www.wellbrook.uk.com/longwire.html

FWIW - This webpage has two Drawings / Diagrams :
"The Wrong Way" -and- "The Correct Way"
plus a brief description of the 'Whys' and 'Hows'
of this "Low Noise Antenna" design concept.

NOTE - These are labled as "Longwire" Antenna Baluns,
but in reality they are mostly used on the more common
"Random Wire" Antennas that the majority of SWLers
are able to build and use in their backyards or outside /
inside the house.

AGAIN - The Right-Way {and Wrong-Way} to Install
a LongWire {Random Wire} Antenna.
http://www.wellbrook.uk.com/longwire.html

Low Noise Longwire Antenna using the UMB -by- Wellbrook.
http://groups.google.com/group/rec.r...5cc467b35a70d5

The "Correct Way" to Install a Longwire Antenna and Balun
by Wellbrook - Using the Far-End Feed-Point Concept
http://groups.yahoo.com/group/Shortw.../message/11773

The "Correct Way" to Install a Longwire Antenna and Balun
by Wellbrook = http://www.wellbrook.uk.com/longwire.html
We have all most likely done it the wrong way more than once . . .

A 'key-point' that Wellbrook makes is the Five Metre (5m)
"Noise Zone" that exists around a House and getting the
Wire Antenna Element away {out} from this area.
http://www.wellbrook.uk.com/longwire.html

NOTE - The above "Correct Way" installation will ensure
that the Wire Antenna Element is 'outside' the local
Noise Zone which extends up to Five Metres (16 Feet)
around the House. Also the noise pickup is lower with
the feeder close to the ground -or- buried under the
ground a few inches.
-Why- The Antenna and the Balun are within the Local
Noise Zone RFI & EMF {Interference Area} that surrounds
most buildings up to distance of Five Metres (16 Feet).

Read - WHY - The Far-End-Fed Shortwave Listener's
(SWLs) Inverted "L" Antenna
http://groups.google.com/group/rec.r...cfc6b9cb2447c0


all i ask for is five metres beyond the noise - iane ~ RHF {pomkia}
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Old April 30th 08, 04:15 AM posted to rec.radio.shortwave
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Default SWL -Newbies- Installing an Inverted "L" Antenna : The Right-Way !

In article
,
RHF wrote:

On Apr 18, 12:22*pm, RHF wrote:
On Apr 18, 5:54*am, Dave wrote:


RHF wrote:


SNIP

Nothing interesting. Nothing useful.

--
Telamon
Ventura, California
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Old April 30th 08, 04:22 AM posted to rec.radio.shortwave
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Posts: 2,053
Default SWL -Newbies- Installing an Inverted "L" Antenna : The Right-Way!

Telamon wrote:

RHF wrote:


SNIP

Nothing interesting. Nothing useful.




Completely unlike your response to him.







mike
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