Balun for long wire
Robert Daniel
short wave receiver. Palomar advertises one for this purpose.
Have antenna now, want to know if balun added is worth while.
TIA Robert Daniel
CW
strength and reduction in noise. There are two or three on the market, the
Palomar being one of them. They are just a 9:1 transformer. The one I use is
homemade. Much cheaper.
--
CW
KC7NOD
Robert Daniel <PAGE...@worldnet.att.net> wrote in message
news:37DA63...@worldnet.att.net...
J W Schermerhorn
Palomars "Magnetic Longwire Balun" is regarded by some to be an
incorrect use of the word "balun". I've never seen one but the design is
apparently flawed because the MLB is mounted high up at the antenna
connection. This requires that the coax must also go up in the air where
it can pick up interference on it's shield and feed the noise into the
center conductor of the coax at the antenna connection point.
It's quite easy to make a balun with the necessary 9:1 ratio for most
"longwire" antennas,which are correctly called an inverted "L". Another
source is an impedance matching transformer such as Drake uses inside
their receivers like the SW8 and R8 series. The part number for it is
2510079. It costs about $4.50. The balun should be installed in a small
box near the point where the vertical downlead from the antenna reaches
the ground. Then you would run a length of coax from the balun box to
your radio. If you need more details on this reply to my e-mail address.
Good luck.
Robert M. Bratcher Jr
>I use one with a 70 wire. It makes a substantial improvement in both signal
>strength and reduction in noise. There are two or three on the market, the
>Palomar being one of them. They are just a 9:1 transformer. The one I use is
>homemade. Much cheaper.
So how do you make one?
How does it connect to the longwire antenna?
CW
Go to the website below. It describes the setup. Credit to John Doty for the
article. If you need further detail, send me an email and I will draw one
up.
-- http://www.anarc.org/naswa/badx/antennas/low-noise_antenna.html
CW
KC7NOD
Robert M. Bratcher Jr <brat...@pdq.net> wrote in message
news:z8jbN7gqblNzGC...@4ax.com...
Robert M. Bratcher Jr
>
>Go to the website below. It describes the setup. Credit to John Doty for the
>article. If you need further detail, send me an email and I will draw one
>up.
>
>-- http://www.anarc.org/naswa/badx/antennas/low-noise_antenna.html
>CW
>KC7NOD
Thanks very much!!!
Jerry Gardner
>Need advice on using balun on long wire for general coverage
>short wave receiver. Palomar advertises one for this purpose.
>Have antenna now, want to know if balun added is worth while.
The use of the term 'balun' is inappropriate here. A balun is a
'balanced-to-unbalanced' transmission line transformer, and that's not
what you want. What you want is an unbalanced-to-unbalanced
transmission line transformer to transform the characteristically high
impedance of a long-wire antenna closer to the 50-ohm impedance of
coax cable.
This device will smooth out the bumpy impedance vs. frequency curve of
a longwire antenna, but it will not reduce noise and improve signal
readibility as so many on this newsgroup seem to think it will.
You can make one of these rather easily using a toroid core taken from
a TV 300-ohm to 75-ohm converter. There are articles on the web that
describe how to wind the core.
If you don't want to make one yourself, then I suggest you buy one from
Industrial Communications Engineers (ICE). Their model 180 is much
batter made than the Palomar model at half the price.
--
Jerry Gardner | "Bill Clinton has all the steely resolve
w6...@hotmail.com | of a kamikaze pilot on his 37th mission."
CW
post. It also decouples the feedline preventing noise picked up on the
outside of the coax from feeding back to your antenna.
--
CW
KC7NOD
but it will not reduce noise and improve signal
> readibility as so many on this newsgroup seem to think it will.
>
Fran Berry
w6...@hotmail.com "Jerry Gardner" wrote:
> The use of the term 'balun' is inappropriate here. A balun is a
> 'balanced-to-unbalanced' transmission line transformer, and that's not
> what you want. What you want is an unbalanced-to-unbalanced
> transmission line transformer to transform the characteristically high
> impedance of a long-wire antenna closer to the 50-ohm impedance of
> coax cable.
Very true, but usage can change or add to meaning. "Balun" is what these
transformers are coming to be called even though it's a misnomer. The
English language is no respecter of origin or root and if it becomes
common in usage, it's eventually deemed correct. It's what makes the
language rich, alive, ambiguous, wonderful and a pain in the arse.
> This device will smooth out the bumpy impedance vs. frequency curve of
> a longwire antenna, but it will not reduce noise and improve signal
> readibility as so many on this newsgroup seem to think it will.
You're right on the first part, but somewhat wrong on the last. These
things provide a DC path to earth which eliminates static build-up on
the antenna, a considerable source of noise in some circumstances.
"Baluns", if installed correctly (mounted outside the dwelling
noise-field and feeding through that noise-field with co-ax), will also
at least aid in the reduction of local noise pick-up.
Fran.
--
_________________________________ ______
( Fran Berry ) ( )
(_) fr...@isis.demon.co.uk (____) (___________ Know Thyself
Jerry Gardner
>Yes it will. This device acts as a fixed averaging tuner. See my previous
>post.
A 'fixed averaging tuner'? Please explain to us how such a wonderful
device works and how it reduces noise and raises the S/N ratio.
Jerry Gardner
>You're right on the first part, but somewhat wrong on the last. These
>things provide a DC path to earth which eliminates static build-up on
>the antenna, a considerable source of noise in some circumstances.
>"Baluns", if installed correctly (mounted outside the dwelling
>noise-field and feeding through that noise-field with co-ax), will also
>at least aid in the reduction of local noise pick-up.
You're right about locally generated noise, especially that
originating from static build-up. I should have been more specific and
said that it doesn't help eliminate non-local atmospheric noise. Why
so many people believe it does is beyond me.
In fact, though, these things don't even reduce local noise because of
the way most of them are designed and installed. Take the Palomar
unit, for example. There's no way to ground the thing right at the
anetnna itself. In order to prevent noise pickup on the coax braid,
you need to ground the braid *at the antenna connection* in addition
to at the receiver connection.
The ICE unit, on the other hand, has a metal case and a ground lug
that makes it easy to ground it. It's also half the price of the Palomar...
CW
an impedance matching device doing the same job as a tuner only non
variable, hence fixed at an average impedance transformation ratio.
Now, would you like instruction on walking and chewing gum at the same time?
--
CW
KC7NOD
Jerry Gardner <w6...@hotmail.com> wrote in message
news:slrn7ttbf...@voyager.home.com...
> On Mon, 13 Sep 1999 19:24:24 -0700, CW wrote:
> >Yes it will. This device acts as a fixed averaging tuner. See my previous
> >post.
>
> A 'fixed averaging tuner'? Please explain to us how such a wonderful
> device works and how it reduces noise and raises the S/N ratio.
>
>
J W Schermerhorn
Unfortunately but perhaps not surprisingly,John Doty seems to have given
up on this NG. He's been one of it's best contributors. Please give it
one more try John!
J W Schermerhorn
Jerry Gardner wrote:
>
> On Sat, 11 Sep 1999 07:15:20 -0700, Robert Daniel wrote:
> >Need advice on using balun on long wire for general coverage
> >short wave receiver. Palomar advertises one for this purpose.
> >Have antenna now, want to know if balun added is worth while.
>
> The use of the term 'balun' is inappropriate here. A balun is a
> 'balanced-to-unbalanced' transmission line transformer, and that's not
> what you want. What you want is an unbalanced-to-unbalanced
> transmission line transformer to transform the characteristically high
> impedance of a long-wire antenna closer to the 50-ohm impedance of
> coax cable.
In the interest of accuracy,it's an un-un.
>
> This device will smooth out the bumpy impedance vs. frequency curve of
> a longwire antenna, but it will not reduce noise and improve signal
> readibility as so many on this newsgroup seem to think it will.
Locating the antenna (particularly the single wire downlead) far from
the house and using coax on the ground back to the house WILL
dramatically lower the noise from household applicances. The balun or
un-un is what permits this design to work well.
>
> You can make one of these rather easily using a toroid core taken from
> a TV 300-ohm to 75-ohm converter. There are articles on the web that
> describe how to wind the core.
Yes there are but have you read this one?:
www.anarc.org/naswa/badx/antennas/low-noise_antenna.html
J W Schermerhorn
Even if you did ground the 'balun' at the antenna,it wouldn't work
because the ground wire would be much too long to be an effective RF
ground. That's why John Doty's solution for the inverted 'L'
(incorrectly called a longwire by some) works so well.
Jake Brodsky
Berry) wrote:
>Very true, but usage can change or add to meaning. "Balun" is what these
>transformers are coming to be called even though it's a misnomer. The
>English language is no respecter of origin or root and if it becomes
>common in usage, it's eventually deemed correct. It's what makes the
>language rich, alive, ambiguous, wonderful and a pain in the arse.
The antenna isolation technique for most SWL antennas should use an
UnUn.
It's an Unbalanced to Unbalanced transformer. The advantage to using
one is that you can isolate the antenna system from the transmission
line system. This makes it possible to reduce the amplitude of
interference sources the transmission line could pick up from inside
your house.
If you checked in to books on the subject, such as the one written by
Jerry Sevik (W2FMI), you'd discover that Baluns and UnUns are actually
constructed differently. These are subtle differences, to be sure.
However, they matter when you start dumping lots of power in to them
or expecting wide ranges of frequencies to be transferred across them
efficiently.
73,
Jake Brodsky, AB3A mailto:fru...@erols.com
"Beware of the massive impossible!"
Don
over 1.5 hrs. Nothing. Yesterday there was a very large amount of noise
on the freq. making it almost unreadable on the left coast.
Don
--
-
CAKE001 - CASF024 - CA6CYF - KHN3161
Location: N33d42m W117d59m UTC -7hrs
Grid Square: DM13AQ
Scanners: Air-8,AR2001,AR900,BC50,
BC101,BC142,BC20/20,BC2500,
BC9000,FRG9600,HP100,HX1000,
HX1500,Pro26,Pro2004/5/6,
Pro2045,Pro2046,R10FM,R532,
R7000,Scout 40,SX200N.
Software: Deltacomm v3.9, Probe v5.0,
ScanCat Gold-SE, ScanStar
Shortwave: DC777,DX160,DX394,ICF2010,
R70, R71A, R1000.
Antennas: 7 Random wires, 6 Discones,
5 Ground planes, 3 Mag-mts,
3 Coax loops, LA-1, Scanner
Beam,X-dipole,2 HF Helical.
Jerry Gardner
>9/15/99
>
>Even if you did ground the 'balun' at the antenna,it wouldn't work
>because the ground wire would be much too long to be an effective RF
>ground. That's why John Doty's solution for the inverted 'L'
>(incorrectly called a longwire by some) works so well.
Who said anything about using a long ground wire to the Unun at the
antenna? In my case, the ICE matching transformer is clamped directly
to the top of an 8' ground rod embedded in the soil. If this is what
you call an inverted-L, then that's exactly what I have.
--
Jerry Gardner | Microsoft isn't the answer. It's the question.
w6...@hotmail.com | No is the answer.
Jerry Gardner
> Again I say, see my previous post on the effects of a tuner. The "Balun" is
>an impedance matching device doing the same job as a tuner only non
>variable, hence fixed at an average impedance transformation ratio.
There is nothing 'average' about the impedance transformation ratio of
an UnUn. It is whatever is it designed to be (3x the turns ratio),
whether it's 6:1, 9:1, or whatever.
And no, I don't need instruction from you in walking, chewing gum, or
anything else. If you'd speak in the language of engineering
(transmission line transformer) rather than the language of CB (fixed
averaging tuner) and indulging in childish name-calling, we'd have an
easier time communicating.
HighWaysinHiding
says...
>
>On Tue, 14 Sep 1999 07:59:42 +0100 (BST), Fran Berry wrote:
>>You're right on the first part, but somewhat wrong on the last. These
>>things provide a DC path to earth which eliminates static build-up on
>>the antenna, a considerable source of noise in some circumstances.
>>"Baluns", if installed correctly (mounted outside the dwelling
>>noise-field and feeding through that noise-field with co-ax), will
also
>>at least aid in the reduction of local noise pick-up.
>
>You're right about locally generated noise, especially that
>originating from static build-up. I should have been more specific and
>said that it doesn't help eliminate non-local atmospheric noise. Why
>so many people believe it does is beyond me.
>
>In fact, though, these things don't even reduce local noise because of
>the way most of them are designed and installed. Take the Palomar
>unit, for example. There's no way to ground the thing right at the
>anetnna itself. In order to prevent noise pickup on the coax braid,
>you need to ground the braid *at the antenna connection* in addition
>to at the receiver connection.
>
>The ICE unit, on the other hand, has a metal case and a ground lug
>that makes it easy to ground it. It's also half the price of the
Palomar...
>
>
>Jerry Gardner | "Bill Clinton has all the steely resolve
>w6...@hotmail.com | of a kamikaze pilot on his 37th mission."
the transformer and where it enters you "shack". The ferrite can
help keep noise from either exiting your shack and getting into your
antenna, or picking up noise on the (in my case vertical wich is worse
for man made crud)coax from the transformer to your radios.
I use a remote "matcher/antenna-tuner" at the end of my "long" wire.
Rollar inductor and 2 capacitors all hooked to some neat little
bidirectional AC motors, with pots to show their position. Works much
better than a simple transformer, but then it is a lot more trouble to
design, scrounge up the parts and build than a transformer.
J W Schermerhorn
It was apparently you that raised the issue.
> Jerry Gardner wrote:
> Take the Palomar unit, for example. There's no way to ground the thing > right at the anetnna itself. In order to prevent noise pickup on the
> coax braid,you need to ground the braid *at the antenna connection* in > addition to at the receiver connection.
Jerry Gardner wrote:
>
> On Wed, 15 Sep 1999 02:20:41 -0700, J W Schermerhorn wrote:
> >9/15/99
> >
> >Even if you did ground the 'balun' at the antenna,it wouldn't work
> >because the ground wire would be much too long to be an effective RF
> >ground. That's why John Doty's solution for the inverted 'L'
> >(incorrectly called a longwire by some) works so well.
>
> Who said anything about using a long ground wire to the Unun at the
> antenna? In my case, the ICE matching transformer is clamped directly
> to the top of an 8' ground rod embedded in the soil. If this is what
> you call an inverted-L,then that's exactly what I have.
>
> --
> Jerry Gardner
Brian Denley
balun mounted at the bottom of the 'L' is any better than one mounted at the
near end of my random wire, if I still have to bring the coax from down
'there' up to the second floor where my receivers are. the length of coax
is shorter this way (although my ground lead is longer). What am I missing?
Brian Denley
--
"There are only two ways to live your life: One is as though nothing is a
miracle. The other is as if everything is." - Albert Einstein
J W Schermerhorn <sk...@capital.net> wrote in message
news:37DF53...@capital.net...
CW
doing it's job.
--
CW
KC7NOD
Brian Denley <bde...@erols.com> wrote in message
news:7s6s0d$m5m$1...@winter.news.rcn.net...
J W Schermerhorn
Brian,
There are at least two key points to the way John Doty set up his "L".
The most important is that the entire antenna is located away from the
house. This means the single wire downlead is also not near the house,so
it doesn't pick up appliance noise from inside the house and feed it to
the receiver. Since the downlead comes down to a foot or two above the
ground (far from the house) it permits using a short and therefore
effective RF ground connection for the coax shield starting at the
balun. Running the coax on/in the ground back to the receiver,with
another ground point for the shield near the house,prevents the shield
from picking up noise in the common transmission mode.
To answer your question specifically,it's the short ground wire in this
configuration which makes it an effective noise reducing design. If the
coax has to go up to the balun,when it's is located at the near end of
the horizontal section,there is no effective way to get a good RF ground
up to this end of the coax shield. Grounding the coax shield at the
house end alone is not sufficient. It would permit the shield,running
from the house to the high balun,to become a common mode antenna and
feed noise back into it's center conductor through the balun.
Hope this helps to clarify the situation. Maybe some others can add to
this.
*****
HighWaysinHiding
>
>9/20/99
>
>Brian,
>
>There are at least two key points to the way John Doty set up his "L".
>The most important is that the entire antenna is located away from the
>house. This means the single wire downlead is also not near the house,so
>it doesn't pick up appliance noise from inside the house and feed it to
>the receiver. Since the downlead comes down to a foot or two above the
>ground (far from the house) it permits using a short and therefore
>effective RF ground connection for the coax shield starting at the
>balun. Running the coax on/in the ground back to the receiver,with
>another ground point for the shield near the house,prevents the shield
>from picking up noise in the common transmission mode.
>To answer your question specifically,it's the short ground wire in this
>configuration which makes it an effective noise reducing design. If the
>coax has to go up to the balun,when it's is located at the near end of
>the horizontal section,there is no effective way to get a good RF ground
>up to this end of the coax shield. Grounding the coax shield at the
>house end alone is not sufficient. It would permit the shield,running
>from the house to the high balun,to become a common mode antenna and
>feed noise back into it's center conductor through the balun.
>Hope this helps to clarify the situation. Maybe some others can add to
>this.
>*****
>
You might want to try some ferrite split "beads" or even torroids(if
you can make several turns with the coax and then put the connectors on).
Try several beads at the radio and the antenna end. It really helped
knock down the interferrence when I got my first computer. A more effective
methode than the old ham trick of coiling several turns of coax (at the
antenna end)to act as an RF choke on limit the effect on antenna patern.
Before flaming me, at least try it, split beads are easy to and cheap these
days. Everytime we through out a peice of modern equipment at work, I
salvage allthe ferrite surpression cores/beads etc. I have even used the
feritte from a TV Horizontal ouput transformer to fairly good effect.
Good listening!
Brian Denley
the house and grounding both ends of the (buried) coax (at the bottom of the
'L' where the matching transformer is, and at the other end) BUT: the other
end is at the house, where John grounds his coax but MY coax would then have
to go UP 20 feet without another ground point which seems to defeat some of
the benefit. I guess there is no perfect setup.
Brian Denley
--
"There are only two ways to live your life: One is as though nothing is a
miracle. The other is as if everything is." - Albert Einstein
J W Schermerhorn <sk...@capital.net> wrote in message
news:37E72A...@capital.net...
> 9/20/99
>
> Brian,
>
> There are at least two key points to the way John Doty set up his "L".
> The most important is that the entire antenna is located away from the
> house. This means the single wire downlead is also not near the house,so
> it doesn't pick up appliance noise from inside the house and feed it to
> the receiver. Since the downlead comes down to a foot or two above the
> ground (far from the house) it permits using a short and therefore
> effective RF ground connection for the coax shield starting at the
> balun. Running the coax on/in the ground back to the receiver,with
> another ground point for the shield near the house,prevents the shield
> from picking up noise in the common transmission mode.
> To answer your question specifically,it's the short ground wire in this
> configuration which makes it an effective noise reducing design. If the
> coax has to go up to the balun,when it's is located at the near end of
> the horizontal section,there is no effective way to get a good RF ground
> up to this end of the coax shield. Grounding the coax shield at the
> house end alone is not sufficient. It would permit the shield,running
> from the house to the high balun,to become a common mode antenna and
> feed noise back into it's center conductor through the balun.
> Hope this helps to clarify the situation. Maybe some others can add to
> this.
> *****
>
> Brian Denley wrote:
> >
> > I do not have an inverted 'L', just a random wire. I can't see where an
9:1
> > balun mounted at the bottom of the 'L' is any better than one mounted at
the
J W Schermerhorn
The section of coax that you're concerned about is not a problem because
any noise on the shield can't feed into the center conductor at the
receiver. It's only a problem at the antenna end of the coax when it's
shield is well above ground. In fact,my coax layout is like yours. I
have about 15-ft of coax going up from the ground outside the house to
my receiver on the second floor. I didn't even ground the shield near
the house and it still works fine. I can now listen to shortwave while
using my computer or when there's a TV on in the house. This was not
possible before I installed this antenna system.
CW
That would work just fine except for price. One can be built for less than
$10.00.
--
CW
KC7NOD
Ai de hua <aid...@aol.com> wrote in message
news:19990924002258...@ng-cp1.aol.com...
> How about using one of the magnetic baluns if it's only a receive antenna?
> Palomar Engineers makes one...
>
> Ed KA6DBY
Ai de hua
J W Schermerhorn
Palomars is very overpriced considering what's inside it.
Daniel Say
: J W Schermerhorn wrote:
:> 9/15/99
:> Unfortunately but perhaps not surprisingly,John Doty seems to have given
:> up on this NG. He's been one of it's best contributors. Please give it
:> one more try John!
: I haven't given up: I'm just very busy right now. It's the busiest year
: of my laboratory's existance. Chandra launched a few weeks ago; HETE-2
: and ASTRO-E launches are coming up in January. Motherrrrs, don't let
: your children grow up to build spacecraft...
Metric or SAE wrenches?
And when is the U.S. going to change
over to metric as most of the world
has except for Liberia, ... etc?
: John Doty "You can't confuse me, that's my job."
: Home: j...@w-d.org
: Work: j...@space.mit.edu