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Old October 21st 05, 02:21 AM
RHF
 
Posts: n/a
Default Better Signal-to-Noise Ratio from a Combination of Improvements including . . . a Ground

For One and All,

Better Signal-to-Noise Ratio from a Combination of Improvements
including . . . a Ground.
http://groups.yahoo.com/group/Shortw...a/message/5961

What I generally 'see' as far as an "Improvement" of the
quality of the RF Signal getting to the Receiver is from a combination
of things.

1. The Wire Antenna Element is placed farther from the House.

2. A 'remote' Ground Rod is used : Again this Ground Rod
is planted in the ground farther away from the House.

3. Use of a Matching Transformer between the Wire Antenna
Element and the Coax Cable : Mounted the Matching Transformer
on the Ground Rod - if possible.

4. Use of a Coax Cable Feed-in-Line : Laying-On -or-
Buried-Under the Ground - if possible.

5. The Extra Mile - Use a well grounded Lightning Arrestor
and/or an In-Line 1:1 Isolation Transformer where the Coax
Cable leaves the Ground and enters the House.

NOTE - All the above is no good if you do not have a very well
Grounded Household Electrical System. Do This First !

RESULTS - Actually in most instances what I 'see' is a reduction
in the S-Meter reading : But I also "Hear" a Greater Reduction
of the Noise Level. Thus the Signal-to-Noise Radio 'improves'
and the Listenability of the RF Signal (Audio) is much Better.

BUT REMEMBER - YOUR PRIMARY USE OF A GROUND IS FOR IMPROVED ELECTRICAL
SAFETY AND LIGHTNING PROTECTION - USE IT [.]


i hope we are communicating - iane ~ RHF
.
.
.. .
= = = In ,
= = = "David G******" davidg******@c... wrote:

JHR Wrote:
"...... I do not mean to contradict you, but my personal
experience with several radios yield the conclusion that
grounding at any point has no effect on receiving.......
.....I just don't get it."

- - - - - - - - - - - - - - - - - - - - - - - - - - - -

DAVE Wrote:
Neither do I. My experience is the same.
I have never witnessed a signal improvement from the use
of a variety of different RF grounds. It think it's
possible that once or twice I think I heard a small
reduction in noise.

I suspect that my house electrical system provides
sufficient ground to yield the maximum differential
between what's on my antenna and ground.
~ Dave
.
- - - - - - - - - - - - - - - - - - - - - - - - - - - -
.
Tous Sont Bienvenus ! - - - Groupe par Radio
d'auditeur d'onde courte pour des Antennes de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Alle Sind Willkommen ! - - - Shortwave Radiozuhörer
Gruppe für SWL Antennen
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Tutti Sono Benvenuti ! - - - Gruppo Radiofonico
dell'ascoltatore di onda corta per le Antenne di SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Todos São Bem-vindos ! - - - Grupo de Rádio
do ouvinte do Shortwave para Antenas de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Все *адушны ! - - - Группа оператора на
приеме
коротковолнового диапазона Radio для
Aнтенн SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
¡Todos Son Agradables! - - - Grupo de Radio
del oyente de la onda corta para las Antenas de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
.
.. .

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Old October 21st 05, 05:58 AM
 
Posts: n/a
Default Better Signal-to-Noise Ratio from a Combination of Improvements including . . . a Ground

For One and All,

For all and one...

Better Signal-to-Noise Ratio from a Combination of Improvements

including . . . a Ground.
http://groups.yahoo.com/group/Shortw...a/message/5961


What I generally 'see' as far as an "Improvement" of the
quality of the RF Signal getting to the Receiver is from a combination
of things.

1. The Wire Antenna Element is placed farther from the House.


This can help if needed. Most of my antennas are over the house.

2. A 'remote' Ground Rod is used : Again this Ground Rod

is planted in the ground farther away from the House.

But again, this is only due to the incomplete antenna that
you are running in that case. "I assume the usual random wire of
whatever config"

3. Use of a Matching Transformer between the Wire Antenna

Element and the Coax Cable : Mounted the Matching Transformer
on the Ground Rod - if possible.

Again, this will almost always have zero effect on s/n ratio.
There is usually no lack of signal without the transformer.

4. Use of a Coax Cable Feed-in-Line : Laying-On -or-

Buried-Under the Ground - if possible.

You do not have to use coax to have low noise reception.
Ladder line can work just as well, if properly balanced.
Coax is just often more convenient, and easier to work with.
But ladder line can be just as quiet. If the coax is poorly
decoupled, it will be as noisy as any unbalanced ladder line.

5. The Extra Mile - Use a well grounded Lightning Arrestor

and/or an In-Line 1:1 Isolation Transformer where the Coax
Cable leaves the Ground and enters the House.

But what does this have to do with improving the s/n ratio?

NOTE - All the above is no good if you do not have a very well

Grounded Household Electrical System. Do This First !

I'm sorry, but this is pure hogwash. You *do not* need *any*
kind of a ground to have a good low noise receiving system.

RESULTS - Actually in most instances what I 'see' is a reduction

in the S-Meter reading : But I also "Hear" a Greater Reduction
of the Noise Level. Thus the Signal-to-Noise Radio 'improves'
and the Listenability of the RF Signal (Audio) is much Better.

Well, sure, you are decoupling the feedline in a better manner.
Ground wouldn't have anything to do with it, except you are using
ground as a method to decouple the feedline. You can decouple
the feedline just as well using other "non grounded" methods.
You are confusing a technique with the actual cure. The actual
cure is the decoupling of the line, not the ground. The ground is
just a method you are using to decouple the line.

BUT REMEMBER - YOUR PRIMARY USE OF A GROUND IS FOR IMPROVED ELECTRICAL

SAFETY AND LIGHTNING PROTECTION - USE IT [.]

I have no argument with this if those concerns are actual.
IE: My battery run IC-706 needs no safety ground. In that
case, it can be ignored.
But my older tube rigs do need to be safety grounded.
In that case, ignoring can be painful...
Most of my antennas are elevated, and my mast does take
strikes from time to time. I *do* have a well grounded mast
for a lightning return, and I have a ground bulkhead outside
my window to ground lines to in bad wx...
But still....Has nothing to do with improving s/n ratio.. :/

i hope we are communicating - iane ~ RHF


Your lips move, but I can't hear what you're sayin....
"optional Pink Floyd content" added as a bonus...
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Old October 23rd 05, 07:46 AM
 
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Default Better Signal-to-Noise Ratio from a Combination of Improvements including . . . a Ground

MK - After all this is a NewsGroup
and 'your' Opinion is Welcome ) ~ RHF

"With my best Elvis impersonation"
Thank ya, vury vury much...

MK - Hey I guess you are right, 'we' should all
pack-up our long wire antennas and sell our radios.
Oops That's a - no, No. NO !

No. Nothing wrong with using any type of antenna.
What is getting you into trouble is applying the technique
used with one particular type of antenna, and imply that it
applies to all. And also you are giving credit to the wrong thing
that improves the antenna you are using. It ain't the ground
in itself, or the transformer, which is almost never actually
needed. It's the decoupling of the feedline. The only reason
ground is mentioned is cuz it's the method used to help
decouple the feedline.
But still in the big picture, the random is fairly lame vs other
choices. It's just how far you want to go with it. If I had to
transmit using random wires, "which I have tried", I would
be miserable. Poor overall performance in general, and a
nightmare as far as rf problems in the shack, etc. Being I
already have full size dipoles for most of the HF bands, it
would be silly for me to use random wires for SWL.
And once you compare the two types, it's not too likely you
would want to use the random wire if you have room for
dipoles. I've also used full size HF ground planes. I often
run one for 40m, 36 ft at the base on a mast. The antenna is
nearly 70 ft tall. It is killer for long haul on the lower -mid HF
bands
late at night. On a path to Australia, that GP would beat my
dipole at 36 ft by appx 4 s units. Using that ground plane, and
1 KW of power I would always be over S 9 in Australia. Once got
a report of 20 db over 9 in Tokyo. That antenna browns the food.
And my dipole would probably beat the average random wire
by 4 s units. Then on the upper HF bands, I have a yagi.
Will hear stuff that wouldn't exist on many random wires due to
the forward gain, and f/b ratio. And it's steerable from the shack.
Use a random wire instead? Thanks, but no thanks.. :/
But I realize, not everyone is me... BTW, a random wire must be
at least one wavelength long on the band in use to qualify as a
"long wire". Pretty easy on the upper bands, but will need a pretty
long wire on the low bands. IE: 4 mhz will need appx 230-240 ft...
MK

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Old October 23rd 05, 03:34 PM
Greg
 
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Default Better Signal-to-Noise Ratio from a Combination ofImprovements including . . . a Ground



From:
Organization:
http://groups.google.com
Newsgroups: rec.radio.shortwave
Date: 22 Oct 2005 23:46:25 -0700
Subject: Better Signal-to-Noise Ratio from a Combination of Improvements
including . . . a Ground

MK - After all this is a NewsGroup
and 'your' Opinion is Welcome ) ~ RHF

"With my best Elvis impersonation"
Thank ya, vury vury much...

MK - Hey I guess you are right, 'we' should all
pack-up our long wire antennas and sell our radios.
Oops That's a - no, No. NO !

No. Nothing wrong with using any type of antenna.
What is getting you into trouble is applying the technique
used with one particular type of antenna, and imply that it
applies to all. And also you are giving credit to the wrong thing
that improves the antenna you are using. It ain't the ground
in itself, or the transformer, which is almost never actually
needed. It's the decoupling of the feedline. The only reason
ground is mentioned is cuz it's the method used to help
decouple the feedline.

(snip)

MK- Please elaborate. I am under the impression that:

1. A random-length "inverted L" wire antenna with coax lead-in is a good
choice for a simple, effective receive antenna for 1.8 to 30mHz listening.

2. That the matching transformer, with proper ground, is a simple,
practical, easy way to mitigate extraneous RF noise.

Is there a better single antenna that covers the HF spectrum? And what are
other ways to decouple the feedline?

Thanks,

Greg



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Old October 23rd 05, 08:19 PM
 
Posts: n/a
Default Better Signal-to-Noise Ratio from a Combination of Improvements including . . . a Ground

MK- Please elaborate. I am under the impression that:

1. A random-length "inverted L" wire antenna with coax lead-in is a
good
choice for a simple, effective receive antenna for 1.8 to 30mHz
listening.

It's ok for general use. I'm not against random wires. Just RHF's
description of why or how they work...

2. That the matching transformer, with proper ground, is a simple,
practical, easy way to mitigate extraneous RF noise.

The matching transformer has nothing to do with it. The ground is
used as a method to help decouple the feedline. It's the decoupling
of the line that mitigates common mode currents. All the matching
transformer does is change impedance. But impedance/ SWR, etc,
have *nothing* at all to do with common mode currents flowing on
the shield. Nada. Zilch. The only reason people use the transformer
is to provide a better transfer of power. But it's almost always
overkill.
The use of one can pump up the S meter, but it rarely improves the
s/n ratio. In some cases, the transformer can actually degrade the
signal if the original match was better than the new one.

Is there a better single antenna that covers the HF spectrum? And what
are
other ways to decouple the feedline?

Dunno. Just depends on the needs, path, time of day, freq, etc, etc.
No one antenna is best for everything. Thats why I have several.
For general multiband use, I like paralleled dipoles fed with a single
coax.
A 1:1 balun or a coax choke at the feedpoint is used to decouple the
line.
Some like a dipole fed with ladder line and tuner. The dipole would be
cut for the lowest band to be used.
Some like a large loop fed in the same manner. There are a zillion
antennas that can be used. It depends on the antenna, etc, but with
most
systems, baluns or chokes are the most common decoupling devices.
With elevated ground planes, the radials help decouple the line, and
extra "decoupling radials, cones, sleeves, etc can be used.
With the random wires, grounding the shield, or chokes are commonly
used. But the use of ground as a decoupling aid is only used on
incomplete antennas like coax fed random wires, ground mount verticals,

etc.. You won't see that used on many "complete" antenna systems.
MK



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Old October 23rd 05, 09:08 PM
Greg
 
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Default Better Signal-to-Noise Ratio from a Combination ofImprovements including . . . a Ground



From:
Organization:
http://groups.google.com
Newsgroups: rec.radio.shortwave
Date: 23 Oct 2005 12:19:53 -0700
Subject: Better Signal-to-Noise Ratio from a Combination of Improvements
including . . . a Ground

MK- Please elaborate. I am under the impression that:

1. A random-length "inverted L" wire antenna with coax lead-in is a
good
choice for a simple, effective receive antenna for 1.8 to 30mHz
listening.

It's ok for general use. I'm not against random wires. Just RHF's
description of why or how they work...

2. That the matching transformer, with proper ground, is a simple,
practical, easy way to mitigate extraneous RF noise.

The matching transformer has nothing to do with it. The ground is
used as a method to help decouple the feedline. It's the decoupling
of the line that mitigates common mode currents. All the matching
transformer does is change impedance. But impedance/ SWR, etc,
have *nothing* at all to do with common mode currents flowing on
the shield. Nada. Zilch. The only reason people use the transformer
is to provide a better transfer of power. But it's almost always
overkill.
The use of one can pump up the S meter, but it rarely improves the
s/n ratio. In some cases, the transformer can actually degrade the
signal if the original match was better than the new one.

Is there a better single antenna that covers the HF spectrum? And what
are
other ways to decouple the feedline?

Dunno. Just depends on the needs, path, time of day, freq, etc, etc.
No one antenna is best for everything. Thats why I have several.
For general multiband use, I like paralleled dipoles fed with a single
coax.
A 1:1 balun or a coax choke at the feedpoint is used to decouple the
line.
Some like a dipole fed with ladder line and tuner. The dipole would be
cut for the lowest band to be used.
Some like a large loop fed in the same manner. There are a zillion
antennas that can be used. It depends on the antenna, etc, but with
most
systems, baluns or chokes are the most common decoupling devices.
With elevated ground planes, the radials help decouple the line, and
extra "decoupling radials, cones, sleeves, etc can be used.
With the random wires, grounding the shield, or chokes are commonly
used. But the use of ground as a decoupling aid is only used on
incomplete antennas like coax fed random wires, ground mount verticals,

etc.. You won't see that used on many "complete" antenna systems.
MK

Okay, thanks. I'm starting to get the picture, though I'm not familiar with
the coax choke. I guess I'll do a little more googling.

Greg

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Old October 25th 05, 04:31 AM
RHF
 
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Default Better Signal-to-Noise Ratio from a Combination of Improvements including . . . a Ground

"N" - and so what do you recommend to a Shortwave Listener
(SWL) who simply has a 25-30 Foot Square Backyard ? ? ?
This same Broadcast Program SWL, who only can get their
Antenna Wire up about about 15-20 Feet High; and wants to
hear everything from 500 kHz thru 30 MHz ? ? ? ~ RHF
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