PAR EFL-SWL Antenna, and Inverted-L Antenna Questions
Robert11
Have been putting a fair amount of time into
trying to understand antenna radiation patterns.
Guess I finally have to admit that I'm 3d challenged, and frankly have
difficulty in visualizing them.
So, let me just ask:
Am thinking of purchasing a PAR EFL- SWL receive only antenna for my attic.
Can probably be considered as an end fed dipole
Will probably run it as an inverted L, with the vertical section being about
10 feet, and going from the attic to the floor below where the radio is. As
the total length is 45', this would leave 35 feet going horizontally.
(placing outside would not be practical)
Interested in as omni as possible, as do listening most anywhere from 0.5 to
30 MHz.
Have two questions, please:
a. anyone ever use this antenna ? Think it would be "substantially" better
than what I have now which is a simle random length wire going around the 4
sides of my attic. Would sure appreciate any thoughts and opinions on this
PAR unit.
b. How "omni" is it ?
e.g.,
If I have the wire axis running N-S, is most of the sensitivity then in the
E-W direction (perpendicular to the wire) ?
If so, will I pick up "anything" in the N-S direction ?
Thanks,
B
David
sdan...@nyc.rr.com
Telamon
"Robert11" <rgs...@notme.com> wrote:
The antenna will pick up stations in all directions. Usually the issue
here is the height above ground which will determine the horizon
visibility of the antenna. The higher up the antenna the more horizon it
will see and have a lower angle of reception. Generally the higher up
the antenna is the stronger the signal will be that it picks up. Being
in your attic it's probably on the order of 20 feet off the ground so it
will have a tendency to distort any pattern it may have higher off the
ground. Being in the attic will further distort the innate pattern the
antenna may have and spread out any lobes in the pattern.
--
Telamon
Ventura, California
David
RHF
when you say the least :o)
DaviD - and these blank posts
almost make 'you' sound like
. . . an intellectual genus ;-}
just for the fun of it ! :0/ ~ RHF
.
.
. .
.
RHF
David
RHF
.
.
. .
.
David
wrote:
Sometimes a banana is just a banana...
RHF
but then again . . . ~ RHF
David
wrote:
Down boy. You've been spending too much time in the Bay Area...
RHF
Maybe it is you who is projecting :o) ~ RHF
.
.
. .
.
Telamon
"RHF" <rhf-new...@pacbell.net> wrote:
> DaviD - 'you' are most eloquent . . .
< Snip >
What does this and the next 8 responses have to do with the original
posters questions?
--
Telamon
Ventura, California
RHF
I was waiting for Dale Parfitt [W4OP] to reply to this Question.
FWIW - I have a Par EF-SWL Antenna setting right next to me
in the box as I Write : More about your Questions and Details
about the Par Electronics EF-SWL Antenna in the next post.
This may be of some interest concerning the Par Electronics
End-Fed Shortwave Listener's EF-SWL Antenna.
The Par Electronics End-Fed Shortwave Listener's EF-SWL Antenna
is a very good Shortwave Listening (SWL) Antenna and I recommend
it to any one who wants to get good results right out of the box by
simply adding Coax Cable and a Ground.
PAR Electronics EF-SWL Antenna Info :
http://groups.google.com/group/rec.radio.shortwave/msg/9db0c1f933b5e495
POPCOM=> http://www.popular-communications.com/23HomelandOct04.html
MT=> http://www.monitoringtimes.com/html/mt2003reviews.html
eHAM=> http://www.eham.net/reviews/detail/3707
PAR=> http://www.parelectronics.com/swl_end.htm
UR=> http://www.universal-radio.com/catalog/sw_ant/2205.html
GE=> http://www.grove-ent.com/ANT8.html
READ - PAR Electronics EF-SWL Antenna
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/1666
http://groups.google.com/group/rec.radio.shortwave/msg/ee85739bddf54cc3
Setting-Up the Ground Connection
READ: Par Electronics EF-SWL" End-Fed Shortwave Antenna
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/277
http://groups.google.com/group/rec.radio.shortwave/msg/672c697b586250c4
Question - Do you have a 'portable' AM/FM Shortwave Radio ?
Then Read Setting-Up a Par EF-SWL Antenna with a 'portable' AM/FM
Shortwave Radio using an External Antenna 1/8" Mono-Jack Input.
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/1649
READ - Lets Think : Out-of-the-Box {Ready-Made}
Shortwave Listener (SWL) Antennas for a Minute.
http://groups.google.com/group/rec.radio.shortwave/msg/a91e9554b3d7d7ee
i have a par ef-swl antenna setting right next to me
in the box as i write - iane ~ RHF
[ More about your Questions and the
Par EF-SWL Antenna in the next post. ]
.
.
All are WELCOME and "Invited to Join" the
Shortwave Listener (SWL) Antenna eGroup on YAHOO !
<http://groups.yahoo.com/group/Shortwave-SWL-Antenna/>
SWL ANTENNAS GROUP => http://tinyurl.com/an6tw
.
Some Say: On A Clear Day You Can See Forever.
I Believe : On A Clear Night You Can Hear Forever
. . . and Beyond , , , The BEYOND ! ! !
With a Shortwave Listening Antenna of your own making.
"If You Build It {SWL Antenna} You Will Hear Them !"
<http://groups.yahoo.com/group/Shortwave-SWL-Antenna/>
SWL ANTENNAS GROUP => http://tinyurl.com/an6tw
RHF
The Par Electronics End-Fed Shortwave Listener EF-SWL Antenna
will work in your Attic. And the Inverted "L" Antenna configuration
is generally a good choice to use with a the Par EF-SWL Antenna
for a "Low Noise SWL Antenna" using the 'design concepts' that
were popularized by John Doty.
Often enough I have written {Fingers On Automatic Typing}
CONSIDER BUILDING A "LOW NOISE" ANTENNA:
Try building an Improved SWL Random Wire Antenna that uses a
9:1 Matching Transformer (Balun / MLB) then you may not see
any real 'improvement' in your receive signal.
This is the so called "Low Noise" SWL Antenna.
Three "Must" Links to Read -wrt- Low Noise SWL Antenna
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/949
[ Please READ These Three Links ]
http://www.anarc.org/naswa/badx/antennas/low-noise_antenna.html
http://www.anarc.org/naswa/badx/antennas/SWL_longwire.html
http://www.anarc.org/naswa/badx/antennas/grounding.html
ABOUT THE "LOW NOISE" ANTENNA 'DESIGN CONCEPTS':
A Random Wire Antenna Element coupled via a 9:1 Matching
Transformer at the Near-End of the Antenna with a Ground
Rod and Coax Cable Feed-in-Line to the Receiver. This is
the basic SWL Antenna that uses the "Low Noise Antenna"
'design concepts' that were {popularized} by John Doty.
.
And the SWL type of Inverted "L" Antenna is is a really good
recommendation for an Out-Side Wire Antenna. But . . .
there is a better SWL Antenna configuration for an In-the-Attic
Antenna. And that Antenna is... The Horizontal [Flat] Loop Antenna.
WHY NOT - The Inverted "L" Antenna In-the-Attic ?
1. The Attic Antenna does not need the Vertical-Up-Leg of
the Inverted "L" Antenna because the Wire Antenna Element
is already elevated and the Coax Cable Feed-in-Line is used
to accomplish what the Vertical-Up-Leg did in Elevating the
Main Part of the Antenna.
2. Because of the In-the-Attic Location a Separate Out-Side
Remote Ground for the Antenna Feed-Point is not practical
and because of the Starting Elevation of the Wire Antenna
Element In-the-Attic the Ground Wire tends to be very long
and is often very ineffective as an RF Ground. For most
In-the-Attic Antennas the Radio Shack's Ground and properly
Bonding IT to the House's AC Electrical Power Ground is the
Primary Ground for All the Radio Equipment and the In-the-Attic
Antenna. The Outer-Shield of the Coax Cable Feed-in-Line is
the Main path for Ground between the Radio Shack's Equipment
and the in-the-Attic Antenna.
3. We are then simply left with the Wire Antenna Element
within the Attic Space. What is the Best Shape {Configuration}
for this Wire Antenna Element within the confines of the Attic.
A FEW POSSIBLE CONFIGURATIONS OF . . .
AN IN-THE-ATTIC ANTENNA :
1. Simple Straight Horizontal [Flat] Random Wire Antenna
along one side or across a diagonal of the Attic.
2. Bent Horizontal [Flat] Random Wire Antenna along one side
and then along another side of the Attic. [ Flat "L" Antenna ]
3. Square/Rectangle Horizontal [Flat] Random Wire Antenna
running along and around all four sides of the Attic.
4. Off-Center-Fed Windom Antenna which is again a form
of Horizontal [Flat] Random Wire Antenna with a Feed Point
near the Middle vice at one end or the other.
5. Horizontal [Flat] Loop Antenna which is again a form of
Horizontal [Flat] Random Wire Antenna with the Wire Antenna
Element running along and around all four sides of the Attic.
PLACEMENT OF THE WIRE ANTENNA ELEMENT
WITHIN THE ATTIC SPACE :
1. The Wire Antenna Element in most instances should not be
place on the Floor of the Attic with it potential to pick-up more man
made noise due to it proximity to Household AC Electrical Wiring.
2. Except for the Simple Straight Horizontal [Flat] Random Wire
Antenna. The Wire Antenna Element most likely would not run
along the Under-Side of Peak of the Attic Roof.
3. What is Left ? For the Placement of the Wire Antenna Element
inside the Attic ? Look-Out ! & Reach-Out ! The Natural Place and
the Right Placement for the Wire Antenna Element in the Attic is
about Shoulder-to-Eye High above the Attic Floor. Here is Easy to
Work-On/At with the Hands and Eyes and it is Off the Attic Floor;
but not Over-Head. Also, depending on the Pitch of the Attic Roof
the Area to Work-In at this Height is usually still relatively large.
Note - That this also places the Wire Antenna Element about Five
Feet (5') above the Attic Floor and away from most of the Attic AC
Electrical Wiring.
SOMETHINGS ABOUT THE PAR EF-SWL ANTENNA :
1. The Matching Transformer has a 9:1 Ratio and is made-up of
Two Separate Internal Winding that can be configured by the User.
2. Looking at the Matching Transformer Box with the SO-239
Connector facing you there are three Terminals on top of it.
* On the Left is Terminal # 1 is the SO-239 Connector's Outer
Threaded Mechanical Surface which is the Coax Cable's PL-259
Connector's Shield Connection. (Terminal #1 is the Coax Shield)
* In the Center is Terminal # 2 which is the Ground Lead End of
the Antenna Side of the Matching Transformer.
* On the right is Terminal # 3 which is the Wire Antenna Element
End of the Antenna Side of the Matching Transformer.
This has the Wire Antenna Element attached to it when the Matching
Transformer comes from Par Electronics.
Note - That when the Matching Transformer comes from Par
Electronics Terminals # 1 and # 2 have a Jumper Wire between
them : Making both the Coax Cable Shield Ground and the Antenna
Ground "Common" {Joined} to each other.
FWIW - This type of Matching Transformer is usually called an UnUn
and also often marketed as a Magnetic Longwire Balun (MLB).
3. The Three Terminals on the Par EF-SWL Antenna's Matching
Transformer give it a greater utility then most Baluns and UnUns
being marketed; and allow the User to Configure the Matching
Transformer to their individual requirements due to limitations,
location and other factors.
THREE POSSIBLE CHOICES FOR AN IN-THE-ATTIC
ANTENNA USING THE PAR EF-SWL ANTENNA :
1. Straight Horizontal [Flat] Random Wire Antenna along one side
or across a diagonal of the Attic. This is the simplest to do and
easy to lay-out; and most often used.
2. Square/Rectangle Horizontal [Flat] Random Wire Antenna
running along and around all four sides of the Attic. When you
have a small Attic Space or are limited by man made noise sources
to using only part of the Attic; then this may be your best Antenna
Shape - All-Things-Considered !
3. Off-Center-Fed Windom Antenna which is again a form of
Horizontal [Flat] Random Wire Antenna with a Feed Point near
the Middle vice at one end or the other. Remove the Wire Antenna
Element from Terminal # 3 of the Matching Transformer. Measure-off
17 Feet from the Terminal-End of the Wire Antenna Element and
carefully remove about One Inch of Insulation from the Wire. Wrap
a Full-Turn of the Bare Wire around Terminal # 3 and Secure it with
the Nut and Washers. You now have a Windom Antenna with a
Short 17 Foot Arm and a Long 28 Foot Arm. The Windom-in-the-Attic
is recommended when the Radio Shack is in the center-middle of
the House and you are trying to keep the Coax Cable length as
short as possible because of the locations of man made noise
sources within the house and in the Attic.
"MY CHOICE" FOR AN IN-THE-ATTIC ANTENNA
USING THE PAR EF-SWL ANTENNA :
The Horizontal [Flat] Loop Antenna which is again a form of
Horizontal [Flat] Random Wire Antenna with the Wire Antenna
Element running along and around all four sides of the Attic.
Now ideally the Matching Transformer for a "Receive Only" Loop
Antenna would have a 4:1 Ratio; but 9:1 isn't bad when you are
using 'what-you-got' to 'get-the-job-done' : KISAP !
HOW TO CONFIGURE - The Par EF-SWL Antenna's Matching
Transformer for a Coax Cable Fed In-the-Attic Horizontal [Flat]
Loop Antenna.
1. Remove the Wire Jumper between Terminals # 1 and # 2.
[ The Coax Cable's Shield is the Ground Path for this Antenna. ]
2. Remove the Insulator form the Far-End of the Wire Antenna
Element of the Par EF-SWL Antenna. Carefully remove about
One Inch of Insulation from the Wire. (Add a Round Terminal if
you wish to this end.) Connect (Attach) this Far-End Wire to
Terminal # 2 of the Matching Transformer by Wrapping a Full-Turn
around the Terminal and Secure it with the Nut and Washers.
3. Rig the Loop's Wire Antenna Element to suspend it from the
Attic Roof and out of the way.
Results - You now have a 45 Foot Around Horizontal [Flat] Loop
Antenna In-the-Attic.
Alternative - "Longer" Wire Antenna Element can be used with the
Par EF-SWL Antenna In-the-Attic. Simply Lay-Out and Rig whatever
size Horizontal [Flat] Loop Antenna you can make in your Attic and
connect the End of the Wire Antenna Element to Terminals # 2 and
# 3 of the Matching Transformer.
Enjoy your In-the-Attic Shortwave Listener's (SWL) Antenna using
the Par Electronics End-Fed Shortwave Listener EF-SWL Antenna.
for now - enough is enough - iane ~ RHF
Robert11
Just a quick thank to all, for the replies and info.
Appreciate it.
Happy Holidays,
Bob
David
wrote:
>[surgically removed for euthanasia]
You'd communicate better with more space and fewer punctuations.