baluns and longwires
finalquest
I'm looking to put up another longwire after the past years' devastation of
my previous antennae. I've been reading about baluns and matching and am
wondering if they're really needed. Previously I just used the longwire
connected to 50 ohm cable with a ground on the shield. Will a balun make a
difference and is a 1:1 appropriate. Any help is appreciated. Thanks !
David
There's a huge mismatch except on the frequencies where your wire is
resonant. Those probably total 2 or 3 in the entire HF band.
Otherwise the mismatch will eat most of the signal. Plus, your wire
will be feeding all manner of static electricity into your receiver.
RHF
If this is for a "Receive Only" Shortwave Listening (SWL) Antenna
Then Think 9:1 Matching Transformer - Which is sometimes called
a Magnetic Longwire Balun (MLB).
Read - For the Longwire {Random Wire} Antenna to
Coax Cable "Connection" - Think 'Matching Transformer' !
http://groups.google.com/group/rec.radio.shortwave/msg/4eb972a1125c2d8a
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/5343
Read - UnUn - MLB - UMB - LWA
[ The Magic and Power of "Words" ] { Techno Babel }
http://groups.google.com/group/rec.radio.shortwave/msg/3f142938701ed7b3
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/4913
Read - "Ununs" = 'UN' to 'UN'
{ Unbalanced-to-Unbalanced Matching Transformer }
http://groups.google.com/group/rec.radio.shortwave/msg/4e443a5683b72305
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/4900
Read - Magnetic Longwire Baluns (MLBs)
http://groups.google.com/group/rec.radio.shortwave/msg/586447a7ae8b3d82
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/5439
http://groups.google.com/group/rec.radio.shortwave/msg/3c157d690257b8ad
http://groups.google.com/group/rec.radio.shortwave/msg/9471a9cda8d98434
Read - The Magnetic Longwire Balun Question
http://groups.google.com/group/rec.radio.shortwave/msg/619cf228fe152992
Read - RIGGING - The LMZ-75, SWLZ
and RF Systems MLB (Magnetic LongWire Balun)
http://groups.google.com/group/rec.radio.shortwave/msg/9b6df0ac85d0fbea
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/6307
http://groups.google.com/group/rec.radio.shortwave/msg/f577c0e9783e7421
LOW NOISE SHORTWAVE LISTENING ANTENNA :
The Random Wire {Longwire} Antenna
+ plus the 9:1 Matching Transformer
+ plus the Remotely Located Ground Rod
+ plus the Coax Cable feed-in-line
Equals = The design concepts {elements} of the
"Low Noise" Shortwave Listening (SWL) Antenna
Read - ABOUT - The "Low Noise" Antenna design concepts
that were popularized by John Doty :
http://groups.google.com/group/rec.radio.shortwave/msg/a438b087b5e89fee
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/5178
http://groups.google.com/group/rec.radio.shortwave/msg/dea571f3bebdca61
http://groups.google.com/group/rec.radio.shortwave/msg/103fe02cad4e5650
http://groups.google.com/group/rec.radio.shortwave/msg/254620d18b66eeba
http://groups.google.com/group/rec.radio.shortwave/msg/3effeaab835e3bb6
http://groups.google.com/group/rec.radio.shortwave/msg/da4e78044fafe71e
Read - Three "Must" Links to Read -wrt- Low Noise SWL Antenna
http://groups.google.com/group/rec.radio.shortwave/msg/a92bfb8387eb0794
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
This is the so called "Low Noise" SWL Antenna.
Three "Must" Links to Read -wrt- Low Noise SWL Antenna
http://groups.google.com/group/rec.radio.shortwave/msg/b58a885a26f3e925
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.
Read - ABOUT - The Low Noise Inverted "L" Antenna
http://groups.google.com/group/rec.radio.shortwave/msg/3b50b04226dbed21
http://tinyurl.com/4ejjl
http://tinyurl.com/43lhx
http://tinyurl.com/4phm9
http://tinyurl.com/68phl
http://tinyurl.com/4nngb
http://tinyurl.com/559us
http://groups.google.com/group/rec.radio.shortwave/msg/dedfea39dc7bbf6e
Read - Question : Is 'it' a Longwire {Random Wire} Antenna
-or- Inverted "L" Antenna ?
http://groups.google.com/group/rec.radio.shortwave/msg/85364956151adbba
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/6300
well that is my double-nickel - 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/>
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/>
SHORTWAVE ANTENNA FORUM => http://tinyurl.com/an6tw
.
.
. .
.
Telamon
"finalquest" <final...@earthlink.net> wrote:
Needing a BALUN or UNUN depends on the antenna type. Some antennas are
close to the coax impedance and do not need a transformation.
You are talking about putting up a wire type antenna so you could
probably use a 9:1 ratio UNUN.
--
Telamon
Ventura, California
James Douglas
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