Longwire question
test
Question.
I just installed a new longwire antenna. And because I always heard: "'the
more wire the better"' I have installed a sort of long U, doubling my
regular wire lenght...
One end of the U is attatched to an isolator on the first floor and from
there it goes down to the garden to another isolator, and from there it goes
back up to another isolator. The coax goes to a balun and to my ar3000a and
or Kenwood 1000r.
The antenna wires don't touch and they are plastic coated.
did I do the right thing? seems have a lot of interference....
txs
7373
Joost
Markus L
A balun matches a balanced load (a symmetric antenna such as a dipole) to an
unbalanced source (coaxial cable). Does not make any sense to me to feed a
longwire via a balun. Maybe you are using an "unun" acting as impedance
transformer between 2 unbalanced sides?
The increased interference you mention may be caused by overloading your RX,
especially if it has no preselector in its front end.
Just my 2c worth...
test
"Markus L" <uo9...@lnubb.pbz> schreef in bericht
news:uKiTd.82$826....@ns2.gip.net...
RHF
.
Yes - In general the more Wire the Better "Works" to a degree;
and your two Shortwave Receivers can handle more wire then most
'portable' AM/FM Shortwave Radios.
.
What you call a Longwire Antenna is more generally described as
a Random Wire Antenna; because it is not 'cut' for one frequency
and one or more Wave Lengths (WL) long.
.
For a Shorwave Listener's (SWL) Random Wire Antenna the 'preferred'
lay-out is to have a Long and Elevated Wire Antenna Element that is
connected to a Matching Transformer (near ground level) with a
Ground Rod and Ground; using a Coax Cable Feed-in-Line to the
Radio/Receivers.
.
READ - The Inverted "L" Antenna - It's 'basic' Lay-Out and Structure
The Inverted "L" {Shortwave Listerner's} Antenna - "Why-It-Works"
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/1969
http://groups-beta.google.com/group/rec.radio.shortwave/msg/e0b3ddbed819958d
.
For a Shortwave Listerner's (SWL) Antenna 'bending' the Antenna
Wire Element is not a problem. Using Insulated (Plastic Overed)
Wire has its Advantages and 'stranded' wire is usually easier to
work with then solid. The use of Insulators at the Wire-Ends and
other Mounting Points is a 'good' Construction Technique.
.
READ - Three "Must" Links to Read -wrt- Low Noise SWL Antenna
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/949
.
READ - "Low Noise Shortwave Listener (SWL) Antenna
for most Radio/Receivers" [NO Antenna Tuner Required]
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/1525
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/1024
.
For most Shortwave Listeners (SWLs) who are considering building
and using a Low Noise Inverted "L" Antenna.
.
READ - Inverted "L' Antenna Reading List
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/374
.
READ - The 'simple' Answer (in most cases) is the
Low Noise Inverted "L" Antenna
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/1785
.
NOTE - When properly laid-out, arranged and constructed;
the Inverted "L" Antenna provides a relatively 'low noise'
"Omni-Directional" Shortwave Listener's (SWL) Antenna.
.
iane ~ RHF
.
All are WELCOME and "Invited to Join" the
Shortwave Listener (SWL) Antenna eGroup on YAHOO !
<http://groups.yahoo.com/group/Shortwave-SWL-Antenna/>
.
Some Say: On A Clear Day You Can See Forever.
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/502
.
I BELIEVE: On A Clear Night . . .
You Can Hear Forever and Beyond, The BEYOND !
With a Shortwave Listener SWL Antenna of your own making.
"If You Build It {SWL Antenna} You Will Hear Them !"
.
.
.
Moi
"RHF" <rhf-new...@pacbell.net> schreef in bericht
news:1109251659.6...@f14g2000cwb.googlegroups.com...
ShortwaveMan
it by passing radio waves or waves of any electromagnetic type. You will get
more noise, and if your radio isn't sufficiently selective you will have
more signals overlapping because they are stronger. The other side of the
coin is that you will get more of a weak signal too. The best radioes are
able to operate well with weak signals with nearby strong ones without undue
interference. A ground may help a lot. A metal rod pounded into the ground
is good - keep the length of the wire connecting the receiver to the ground
as short as possible. If you have other radioes, tv's computers etc., keep
them turned off while you listen.
~~~~~ God gives Peace not war +
"Moi" <te...@test.nl> wrote in message news:cvkn3h$j20$1...@reader11.wxs.nl...
mongo
Sanjaya
"mongo" <we...@adelphia.net> wrote in message news:2cudneazlMb...@adelphia.com...
> http://www.universal-radio.com/catalog/antsup/1484.html
I don't see a ground lead on that one.
How does one ground it?
tianli_
> If the free ends of the "U" are close and you get bored or frustrated by
> the noise, you might want to consider bringing the ends of the wire to
each
> side of your feedline and turning it into a loop-antenna. Ground one side
> at the feedpoint (if you can). It *may* help a bit and it's free to try.
Large horizontal loops are very broadbanded. If the loop is about 2 X the
wave length on the lowest band you wish to receive then it will perform
better than any dipole, at the same height, cut for one particular band and
its harmonics. Of course the higher the better is always the key for most
any antenna.
Do experiment with the large horizontal loop.
RHF
.
RF Systems Magnetic Longwire Balun (MLB)
NOTE - This is basically a Matching Transformer that is an
UnUn where both Windings share a Common Ground. The Shack's
Ground via the Coax Cable provides the Ground to both sides
of the Matching Transformer.
.
NOTE - The Body of the RF Systems Magnetic Longwire Balun
(MLB) is Non-Metalic {Plastic} so the only exposed Grounding
Point is the Outer-Threaded-Metal SO-239 Jack.
.
TIP - Install your Longwire (Random Wire) Antenna as an
Inverted "L" Antenna.
- Place an Eight Foot (8') Ground Rod at the 'base' of
the Down-Leg of the Inverted "L" Antenna.
- Leave 8"-10" of the Ground Rod above ground level.
- Attach the Coax Cable to the MLB and place the MLB
next to the Top of the Ground Rod.
- Use a piece of Copper or Brass Wool between the Outer
Threaded Metal Sleave of the Coax Cable's PL-259 Connecter
and the Top of the Ground Rod.
- Use a Hose-Clamp to Mount and Secure the Outer Threaded
Metal Sleave of the the Coax Cable's PL-259 Connecter and
the Top of the Ground Rod.
.
FWIW - Here are a few MLB type Matching Transformers that
are like the RF Systems Magnetic Longwire Balun (MLB) :
* Shortwave Longwire Antenna Feeder with Balun LWF-1
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5754429127
* Magnetic Longwire Balun (MLB) Palomar
http://www.palomar-engineers.com/MLB-1/mlb-1.html
* Shortwave Longwire (10:1) Antenna Feeder #SWL-1
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5754507955
.
- = V E R S E S = -
.
"AMANDX PRESENTS" - by Shawn Axelrod
http://www.angelfire.com/mb/amandx/index.html
"Remmber On A Clear Day You Can Hear Forever !"
.
Has a WebPage for the Longwire Impedance Matcher (LIM)
from Durham Radio.
http://www.angelfire.com/mb/amandx/lim.html
Shortwave Store "Longwire Impedance Matcher" (LIM)
http://usa.shortwavestore.com/longwire-impedance-matcher.html
As you can see this type of Matching Transformer has
a Ground Lug for the direct attachment of the Ground Wire
to the Matching Transformer along with the Antenna Wire
and the Coax Cable.
.
FWIW - Here are a few LIM type Matching Transformers that
are like the Durham Radio Longwire Impedance Matcher (LIM) :
* WiNRADiO WR-LWA-0130 Long Wire Antenna Adapter
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/230
http://www.winradio.com/home/lwa.htm
* Longwire Isolated (10:1) Antenna Feeder - SWL-1G
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5754693416
* "Universal Magnetic Balun" (UMB) by Wellbrook
UMB=> http://www.wellbrook.uk.com/UMB.html
.
.
OR-HAVE-IT-YOUR-WAY :
The Third Option is the "Par Electronics End-Fed Shortwave
Listener (EF-SWL) Antenna" that uses a Matching Transformer
that is designed to have its Grounding Connections be
'configured' by the user for the best Noise Reduction
for your individual Antenna Set-Up and Location.
http://www.parelectronics.com/swl_end.htm
http://www.universal-radio.com/catalog/sw_ant/2205.html
http://www.eham.net/reviews/detail/3707
http://tinyurl.com/56pt2
Also Read - These Three Messages :
* "PAR Electronics EF-SWL Antenna
- Setting-Up the Ground Connection"
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/1666
* Par Electronics EF-SWL" End-Fed Shortwave Antenna
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/277
* Setting-Up a Par EF-SWL Antenna with a 'portable' Shortwave
Radio using an External Antenna 1/8" Mono-Jack Input.
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/1649
big boy now
But there is a down side the longer the wire the more you receive including
interference. you could try useing an Antenna Tuner preselector...
"RHF" <rhf-new...@pacbell.net> wrote in message
news:1109251659.6...@f14g2000cwb.googlegroups.com...
tianli_
"big boy now"
> in reality the longer the wire the better.
> But there is a down side the longer the wire the more you receive
including
> interference. you could try useing an Antenna Tuner preselector...
Then how would you explain the performance equivalency of a 2Xwavelength
horizontal loop's performance to that of a 1/2wave dipole cut for same
frequency?
http://www.cebik.com/wire/horloop.html
The advantage of this type of loop is that it performs equally to a dipole
on
multiple frequencies. It is an excellent SWL antenna if you have the
real-estate.
Even a 1Xwavelength H-loop performs very well.
clifto
> http://www.cebik.com/wire/horloop.html
>
> The advantage of this type of loop is that it performs equally to a dipole
> on
> multiple frequencies.
The main disadvantage is that you could buy several hundred better
performing antennas for less than the first year's property taxes for
the land needed to construct the damn thing!
Yeesh. This makes my jokes about a 30-element MW log-periodic sound
practical by comparison.
CW
"clifto" <cli...@clifto.com> wrote in message
news:a6v4f2-...@remote.clifto.com...
clifto
> "clifto" <cli...@clifto.com> wrote...
>> tianli_ wrote:
>> > http://www.cebik.com/wire/horloop.html
>> >
>> > The advantage of this type of loop is that it performs equally to a
> dipole
>> > on
>> > multiple frequencies.
>>
>> practical by comparison.
> Pull out your calculator. It's not that big.
Imagine my surprise when my MW loop turned out to be only 1341 feet in
diameter, needing only 33 acres to hold it (41-1/3 if you own the entire
square the circle is inscribed in).
We'd need about 36 poles to hold it half a wavelength, or 1,054 feet,
off the ground.
Maybe we could rent Arecibo... is it big enough?
tianli_
> diameter, needing only 33 acres to hold it (41-1/3 if you own the entire
> square the circle is inscribed in).
>
> We'd need about 36 poles to hold it half a wavelength, or 1,054 feet,
> off the ground.
>
> Maybe we could rent Arecibo... is it big enough?
I don't think anyone is going to go through the trouble of building a H-loop
for the MW BCB. The original post inquired about the feasibility of a
longwire shaped into a "U". He was almost there by a few yards short of a
better performing horizontal loop.
The point of the discussion, and the links I included,
show that a modest horizontal loop has the same dB gain as a dipole AT
THE SAME HEIGHT. The loop advantage is that the dipole performs optimally
on its fundamental and harmonics ONLY, while the H-Loop performs equally
well on all frequencies at and above about its one wavelength circumference.
Read the links and learn.
Jack Painter
"tianli_" <tia...@sina.com.cn> wrote
> The point of the discussion, and the links I included,
> show that a modest horizontal loop has the same dB gain as a dipole AT
> THE SAME HEIGHT. The loop advantage is that the dipole performs optimally
> on its fundamental and harmonics ONLY, while the H-Loop performs equally
> well on all frequencies at and above about its one wavelength
circumference.
Well said. A horizontal dipole is optimal only between 1/4 wave to
preferably 1/2 wave height above ground. Anyone who thinks erecting a
horizontal loop at 1/2 wave height is easy, we've got a bridge in Arizona to
sell you. These horizontal loops are used, but they are typically strung
between the tops of several tall telephone poles erected in a circle.
Nothing you see in a hobbyists backyard.
Jack
tianli_
> Well said. A horizontal dipole is optimal only between 1/4 wave to
> preferably 1/2 wave height above ground. Anyone who thinks erecting a
> horizontal loop at 1/2 wave height is easy, we've got a bridge in Arizona
to
> sell you. These horizontal loops are used, but they are typically strung
> between the tops of several tall telephone poles erected in a circle.
> Nothing you see in a hobbyists backyard.
>
> Jack
>
I would suggest that very few persons actually mount there longwire or
dipoles at the optimum heights.
And even a modestly sized H-loop, say about 80 to 100 Ft in circumference,
would easily fit around the eaves of a roofline as I have actually done.
While a dipole or longwire strung on top of my roof could hardly stretch
across maybe 50 ft at best.
And the dipole/longwire would only be at its optimum - tuned , regardless of
height, at its 1/2 wave frequency and its harmonics. While the H-loop would
be tuned from the 1 wavelength resonance all the way up to 30mHz and beyond!
To give you a more practical comparison the difference is like a 1/2 wave
vertical for a tuned frequency of , say 500mHz, and a discone with a tuned
range of about 30mHz to 900mHz. Roughly equal gain at 500mHz for both
antenna's AT THE SAME HEIGHT. But stray away from 500mHz with the 1/2 wave
vertical and performance drops significantly compared to a discone on any
other frequency. No comparison!
RHF
>From what you have written here; I soumds like
you built yourself a SkyWire Loop Antenna.
.
"SkyWire Loop Antennas" Forum {eGroup} on YAHOO !
SKYWIRE => http://groups.yahoo.com/group/SkyWires/
.
Dr. Ace [WH2T] is one of the Moderators of the eGroup.
http://www.bloomington.in.us/~wh2t/loop.html
.
A Critical requirement for a SkyWire Loop Antenna is "LAND" & Space.
.
SkyWire Loop Antenna Size per Square Side:
160 Meter Band = 529 Feet Loop = 132 Feet per Side = "SPACE"
80 Meter Band = 268 Feet Loop = 67 Feet per Side = 'Space'
40 Meter Band = 141 Feet Loop = 35 Feet per Side = space
20 Meter Band = 71 Feet Loop = 18 Feet per Side
10 Meter Band = 35 Feet Loop = 9 Feet per Side
.
Some SkyWire Loop Antenna Messages to Read :
* Using a SkyWire Horizontal Loop Antenna ? One or Two WaveLengths
Size ?
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/191
* SkyWire Horizontal Loop Antenna = Height ?
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/184
* "SkyWire" Horizintal Loop Antenna is 'by design' an All "Omni"
Directional Antenna
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/151
* SkyWire Loop Antenna Balun (Baluns in General)
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/122
* Which BALUN for the SkyWire Loop Antenna ?
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/121
* Loop Antennas: SkyWire -vise- Rhombic
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/76
* "SkyWire" Loop Antenna
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/55
.
Look Up In The Sky ! - its a bird - its a plane - its sure big !
NOooo It's A SkyWire Loop Antenna ! ! ! and its everywhere . . .
.
Once again for those who are interested in Learning More about
the SkyWire Loop Antenna Check-Out the eGroup on YAHOO !
SKYWIRE => http://groups.yahoo.com/group/SkyWires/
.
give me land lots of land to build antennas on, don't CCR me in ~ RHF
.
.
David
On Sat, 26 Feb 2005 16:06:57 -0500, "Jack Painter" <223...@cox.net>
wrote:
tianli_
Many folks here are missing the point. It doesn't have to be 2X wavelength
or
even 1X wavelength. Just string up a horiz. loop anywhere you can and as
long as you can make it. Don't worry about height above ground or if it is
in a
circular, square or trapezoid, or what have you, configuration. If it is
anywhere
near as high as your proposed longwire or dipole it will work just as well
but
over a much broader swath of frequencies. Think of its performance as much
like a discone antenna at VHF & UHF - no gain over a half-wave vertical but
very broadbanded. The H-loop "generally" has omni-directional
characteristics
where as a dipole or longwire has definite nulls and peaks around the
compass.
I would guess that my H-loop is about at least 70-75 meters in circumference
at an average height of about 20 ft. It is strung around the edge of my
roof in
a large "L" configuration with the wire tucked under the roofing shingles at
strategic locations - invisible! It has survived several seasons of severe
weather and hasn't budged. I use it for SWLing as well as transmitting on
80-10 meters using a vintage Johnson Matchbox - sweet!
Compared to a dipole or a longwire it doesn't experience those "dips" in
reception on certain bands. Any "dips" that do occur are not as deep and
an antenna matchbox will easily make up for it.
Where anyone obtained the idea you must use dozens of 75+ ft telephone poles
around 100 acres of real-estate has simply never built or used a horiz.
loop.
> Granted, it would undoubtedly work better at greater height, my horizontal
> loop encircles a small section of my woods at varying heights of anywhere
> from 6 feet to (maybe) 15 feet. I ran about 475 to 500 feet of wire,
> hanging it off available tree branches as I went, in what is more or less
a
> square with somewhat bulging sides. I couldn't tell you exactly how much
> wire I used, other than I used enough to form a loop through the woods. I
> couldn't tell you it's impedance. I feed it with coax through a home-made
> 1:1 transformer. I have no complaints with it's performance.
>
> I think there's this expectation by folks new to the hobby that everything
> has to be "labratory" perfect or it's a waste of time. In my experience, I
> have found that wire antenna's are *very* forgiving of imperfections.
> Granted, they will not perform as well as something carefully constructed
> in a labratory environment, but they will *still* work - and there's even
> odds (or better than even) they will work better than expected!
>
> My rule of thumb is: "As much wire as you reasonably can, as high as you
> reasonably can." In different situations, that could be 30 feet of wire at
> house-eave level -or- a 2wl horizontal loop at 1wl above dirt. Just do
> what you can, and are interested in trying, and don't sweat the details
> until *after* you establish a baseline.
>
> -=jd=-
> --
> My Current Disposable Email:
> jd77...@HATpostmark.net
> (Remove YOUR HAT to reply directly)
Jack Painter
"tianli_" <tia...@sina.com.cn> (and jd) wrote in message
news:11242mk...@corp.supernews.com...
> Nice jd!
(( Comments inserted between text ))
--
While it sounds like you have little more than a cloud warmer there (if
otherwise please do advise), you're right that it costs very little to run a
few hundred feet of wire anywhere you can get it. The result could be a
good listening antenna. What it won't normally be is a good transmitter,
unless it meets mimimum design conditions.
Also, don't you worry what kind of RF you illuminate the house with? It
looks to me like people inside could be as close as 2 or 3' from your
antenna, and at most HF frequencies that is way too close to 100+w transmit
power.
--
> Compared to a dipole or a longwire it doesn't experience those "dips" in
> reception on certain bands. Any "dips" that do occur are not as deep and
> an antenna matchbox will easily make up for it.
>
> Where anyone obtained the idea you must use dozens of 75+ ft telephone
poles
> around 100 acres of real-estate has simply never built or used a horiz.
> loop.
>
--
That would be me. I have seen one in use, just never replicated by a
hobbyist (yet). Without the near 1/2 wave design-elevation, a horizontal
wire antenna becomes NVIS (or cloud warmer). We've all heard of people
doing this with their rain gutters for years, but that doesn't translate to
a worthwhile effort when compared to most achievable antenna designs.
--
True enough.
Jack
Jack Painter
"-=jd=-" <jd77...@HATpostmark.net> wrote
/snip
> For now, I have no interest in talking. Though, I have often
> thought of working towards the General ticket just to see if I could pass
> the tests, simply out of personal curiosity.
>
> -=jd=-
I couldn't memorize 1 wpm of Morse code in the Boy Scouts, doubt that it is
going to happen 35 years later ;-) I'm on the air for the USCG and they
don't care if we know code or not. A smaller and smaller number of older
chiefs and officers who were hams for a hundred years still know code in the
guard - not much interest in it or radio in general by younger generations,
even when they operate them for a living. Computer networking is what
drives the communication business today, the radios themselves seem a small,
mostly forgotten part of it.
Sorry to have gotten off-topic with the longwire - for listening it is
certainly the most forgiving of any configuration imaginable.
Jack
RHF
.
You and Tianli are correct. Just as for Shortwave Listening
(SWL) the simplest and easiest answer to a Longwire (or any
other "Formula" Cut-to-Size) Straight Wire Antenna is the
"Random" Wire Antenna.
.
THE SHORTWAVE LISTENER (SWL) HORIZONTAL [FLAT] LOOP ANTENNA :
So to for the Shortwave Listener's (SWL) the Horizontal [Flat]
Loop Antenna can be the Antenna that fits their available space
and gives them the higher Signal Levels and Lower Noise Levels
with a more consistent (less fade) signal. For the Shortwave
Listener (SWL) a "Random" Horizontal Flat Loop Antenna an can
be the answer for a longer larger (more signal capture area)
Antenna to meet their needs.
.
SOME PLUSES - For a Shortwave Listener (SWL) in using the
Horizontal [Flat] Loop Antenna are :
.
+ Generally Lower Noise
.
+ Generally Omni-Directional
.
SIZE - HORIZONTAL [FLAT] LOOP ANTENNA -vice- RANDOM WIRE ANTENNA :
.
* Room-Size (Indoor) Ten Foot (10') Square Horizontal Loop Antenna
= 40 Foot Random Wire Antenna
.
* Very Small 15 Foot Square Horizontal Loop Antenna
= 60 Foot Random Wire Antenna
.
* Small 20 Foot Square Horizontal Loop Antenna
= 80 Foot Random Wire Antenna
.
* Moderate - Average 25 Foot Square Horizontal Loop Antenna
= 100 Foot Random Wire Antenna
.
* Medium 30 Foot Square Horizontal Loop Antenna
= 120 Foot Random Wire Antenna
.
* Large 35 Foot Square Horizontal Loop Antenna
= 140 Foot Random Wire Antenna
.
* Bigger 40 Foot Square Horizontal Loop Antenna
= 160 Foot Random Wire Antenna
.
* Extra-Large 45 Foot Square Horizontal Loop Antenna
= 180 Foot Random Wire Antenna
.
* Giant 50 Foot Square Horizontal Loop Antenna
= 200 Foot Random Wire Antenna
.
HEIGHT ABOVE GROUND :
Some comments may be made about this being a "Cloud Warmer"
or a "Near Vertical Incident Skywave" {NVIS} Antenna.
NVIS=> http://www.qsl.net/k5eph/nvis.htm
.
IMHO - In general this is a good characteristic for a Shortwave
Listener (SWL) Antenna.
.
For use as a Shortwave Listener (SWL) Antenna the Horizontal
[Flat] Loop Antenna can be mounted at just about any Height
that is easy and available to use. A general Height of 12
to 18 Feet is easy to achieve and works well. While near
"Flat" is nice : All Corners (mounting points) do not have
to be the same Height. Usually the main objective is to get
it "UP" above your Head (non-hazard) so the Loop's Wire can
be as little as Eight to Ten Feet High. Anything above 25
to 30 Feet is really not necessary unless that is all the
mounting point at are Available.
NOTE - For a No-See-Um Horizontal Loop Antenna the Wire can
be run around near the Top of a Fence. Or around the House
under the Eaves.
.
SHAPE OF THE LOOP :
A Circle would be perfect and a Square would be nice.
But the simple fact is that for a Shortwave Listener (SWL)
this is a "Random" Loop Antenna that is put-up in the
available Space. Any general "Shape" using the existing
structures as mounting points or any mounting points that
you can easily erect should work well. The "Sides" of
the Loop do not all have to be the same Length. The
important thing is the Shape allows the Starting-Point
of the Wire and the Ending-Point of the Wire come together
to form a Loop.
.
FEED-IN-LINE FOR THE LOOP :
The Feed-in-Line for the Horizontal [Flat] Loop Antenna
can take many forms. Directly Wired 300 Ohm TV type
Twin Lead or Coax Cable and even Speaker Wire could be
used as a Feed-in-Line.
NOTE - When a Coax Cable is used as a Feed-in-Line :
A Matching Transformer {Balun} can also be used between
the Loop's Wire Antenna Element and the Feed-in-Line.
The Balun can be a 1:1 Radio or a 1:4 Radio.
.
GROUNDING FOR THE LOOP :
Since the Horizontal [Flat] Loop Antenna is a Balanced
Antenna a Ground for the Antenna itself is not required.
However, this does not eliminate the Requirement for a
good Earthen Grounding Point for the Shack's Equipment
and Radio/Receivers.
.
.
BUILDING A SIMPLE AND PRACTICAL TV "Type" PARTS
"RANDOM" HORIZONTAL [FLAT] LOOP ANTENNA :
1. Use 50 Foot or more of TV 300 Ohm Twin Lead as the Loop
Antenna Wire Element. This can be connected either in
Parallel as a Double-Wire Single Loop Element; or in Series
as a Two Loop Element.
2. Use a TV 300 Ohm to 75 Ohm Matching Transformer as a
Balun between the the Antenna's Wire Loop Element and the
Coax Cable Feed-in-Line.
Note- Find one that is labeled with a 5 MHz bottom
frequency rating.
3. Use TV 75 Ohm Coax Cable with "F" Connectors as the
Feed-in-Line from the Loop Antenna's Wire Element and
Matching Transformer to the Radio/Receivers.
4. Use what ever connector Adapter is need to connect
the TV 75 Ohm Coax Cable to the Radio/Receivers.