Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

Dave wrote:

...
The advantage of a physical height (antenna length) between 180 and 215
degrees (see previous post regarding the magic number being around 195
degrees) is improved take-off angle and reduced skywave-groundwave
interaction, not dramatic nearfield voltage increases.

As I previously stated, works nicely on paper/software; in real life, I
have not been able to construct an antenna which demonstrates an
advantage to justify the difficulty of dealing with the extra length.
Now, a 2m on down, why not "toss it on", just in case?

Now, when loading a 1/4 wave physical length antenna to a 1/2 wave
electrical length, I DO see an advantage, increased radiation
resistance, minimal counterpoise required, etc. Even when taking into
consideration the losses added by the coil ...

Regards,
JS

Shortwave Radio Listener (SWL) Antennas -versus- Amateur Radio Antennas
 

"Telamon" wrote in message
...
In article ,
John Smith wrote:

Billy Burpelson wrote:

...
Say what?

He said he "ain't here to be a ham", so why would he want to transmit?

Well, consider me a "different type of ham."

SNIP

Yeah, you are a Trolling Ham and a well done one at that.

And Telamon is just a newgroup troll....so he trumps you.

Antenna for shortwave reception
 

John Smith wrote:
Dave wrote:
John Smith wrote:


I said NO such thing, indeed, I stated the EXACT opposite, it allows
maximum power transfer to the antenna, however, the losses in the
POOR antenna are now increased due to the losses in the matchbox--as
heat. And, no problems which exist in the POOR antenna have been
rectified, they are just masked ...

That is vastly oversimplified.

Absolutely, and at some point I must trust the reader has the resources
to extrapolate; otherwise, all postings would soon turn in to the
length, depth and completeness of a college textbook ...

For example, an antenna is a two lane road, running in both
directions(T/R), the same parameters which allow it to be the best
choice for transmitting, also are in action when that same antenna
"plucks" its' signals from the ether ... something I have pointed out in
multiple ways, multiple times ...

The average person must hear, read, study the same material six times
before "learning" it. And, an instructor once pointed out to me, not
all people respond to the same method, personality, mode-of-presentation
as another or others ... so, he pointed out the importance of gathering
data from multiple sources until the "epiphany" is realized ...

Regards,
JS

You're the guy from Lost in Space!

Antenna for shortwave reception
 

In article , Dave
wrote:

John Smith wrote:
Dave wrote:
John Smith wrote:


I said NO such thing, indeed, I stated the EXACT opposite, it allows
maximum power transfer to the antenna, however, the losses in the
POOR antenna are now increased due to the losses in the matchbox--as
heat. And, no problems which exist in the POOR antenna have been
rectified, they are just masked ...

That is vastly oversimplified.

Absolutely, and at some point I must trust the reader has the resources
to extrapolate; otherwise, all postings would soon turn in to the
length, depth and completeness of a college textbook ...

For example, an antenna is a two lane road, running in both
directions(T/R), the same parameters which allow it to be the best
choice for transmitting, also are in action when that same antenna
"plucks" its' signals from the ether ... something I have pointed out in
multiple ways, multiple times ...

The average person must hear, read, study the same material six times
before "learning" it. And, an instructor once pointed out to me, not
all people respond to the same method, personality, mode-of-presentation
as another or others ... so, he pointed out the importance of gathering
data from multiple sources until the "epiphany" is realized ...


You're the guy from Lost in Space!

You are to kind Dave. The lost in Space Dr. Smith fooled some of the
people some of the time where our Smith fools none of the people none of
the time.

--
Telamon
Ventura, California

Shortwave Radio Listener (SWL) Antennas -versus- Amateur Radio Antennas
 

In article ,
Dave wrote:

Telamon wrote:
In article ,
Dave wrote:

RHF wrote:

Dave,

IIRC a good Amateur Radio 1/4 WL Vertical-Up-Leg
by 1/4 WL Horizontal-Out-Arm {Inverted "L" Antenna
requires very little Tuning and performs very well near
and far on the HF Band that it is 'cut' to use on.
Using a direct-connect or 1:1 UnUn at the Feed-Point
* Half-Wave Inverted "L" Antenna : 1/4 WL + 1/4 WL


Where-as the more common Shortwave Listener (SWL)
type of {Random Wire} Inverted "L" Antenna is un-equal
and usually has a shorter Vertical-Up-Leg and a longer
Horizontal-Out-Arm of at least 1V-to-2H and often
1V-to-3H or more. Using a 9:1 Matching Transformer
and Ground Rod at the Feed-Point which is at the base
of the Vertical-Up-Leg.


"Random" implies otherwise. Instead of a 9:1 UnUn, imagine one of these
at the feed point:

http://www.mfjenterprises.com/Produc...ductid=MFJ-927

I enjoy playing with these kind of things. So I got a license to
transmit. Some call that "elitist", I call it self-indulgent.

I would just call it following your interests.

Remote tuners are the right way to do things. Much better than a tuner
in the shack.

A tuner in the shack matches the radio to the transmission line. There
is still a mismatch at the feedpoint.

Exactly. Then the transmit energy ends up heating the coax to the
antenna and components in the tuner. sarcasm on As a bonus you get RFI
in the shack. Another bonus is high voltage at points in the coax to the
antenna where you could have a flashover condition. Sarcasm off

A tuner at the antenna is a much better setup. You are doing things
right. Most HAM's don't. When Mr. Smith imagines doing this he does it
wrong.

--
Telamon
Ventura, California

Shortwave Radio Listener (SWL) Antennas -versus- Amateur Radio Antennas
 

In article ,
Dave wrote:

John Smith wrote:

However, in side-by-side comparisons on 10-6-2m antennas I have built,
comparing a 5/8 against the 1/2 (construction methods/materials and
matching components identical) ... the actual difference, in the real
world, must be less than the width of a meter needle in the readings ...
or, put simply, I no longer deal with the extra length required of the
5/8 ... your mileage may vary ...


The advantage of a physical height (antenna length) between 180 and 215
degrees (see previous post regarding the magic number being around 195
degrees) is improved take-off angle and reduced skywave-groundwave
interaction, not dramatic nearfield voltage increases.

Regarding Mr. Smith's comments above my experience and others is the
opposite. 5/8 is a much better performing antenna than a 1/2 wave for
local VHF and UHF communications. Well worth the effort to build a 5/8
wave antenna over a 1/2 wave. The 5/8 had some kind of series load coil
part way up the whip where the 1/2 wave match/compensation was done at
the base so the whip was solid. Sorry I can't more specific then that as
those experiments were many years ago.

Mr. Smith is still lost in space.

--
Telamon
Ventura, California

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

Telamon wrote:
In article ,
Dave wrote:

Telamon wrote:
In article ,
Dave wrote:

RHF wrote:

Dave,

IIRC a good Amateur Radio 1/4 WL Vertical-Up-Leg
by 1/4 WL Horizontal-Out-Arm {Inverted "L" Antenna
requires very little Tuning and performs very well near
and far on the HF Band that it is 'cut' to use on.
Using a direct-connect or 1:1 UnUn at the Feed-Point
* Half-Wave Inverted "L" Antenna : 1/4 WL + 1/4 WL


Where-as the more common Shortwave Listener (SWL)
type of {Random Wire} Inverted "L" Antenna is un-equal
and usually has a shorter Vertical-Up-Leg and a longer
Horizontal-Out-Arm of at least 1V-to-2H and often
1V-to-3H or more. Using a 9:1 Matching Transformer
and Ground Rod at the Feed-Point which is at the base
of the Vertical-Up-Leg.

"Random" implies otherwise. Instead of a 9:1 UnUn, imagine one of these
at the feed point:

http://www.mfjenterprises.com/Produc...ductid=MFJ-927

I enjoy playing with these kind of things. So I got a license to
transmit. Some call that "elitist", I call it self-indulgent.

I would just call it following your interests.

Remote tuners are the right way to do things. Much better than a tuner
in the shack.

A tuner in the shack matches the radio to the transmission line. There
is still a mismatch at the feedpoint.

Exactly. Then the transmit energy ends up heating the coax to the
antenna and components in the tuner. sarcasm on As a bonus you get RFI
in the shack. Another bonus is high voltage at points in the coax to the
antenna where you could have a flashover condition. Sarcasm off

A tuner at the antenna is a much better setup. You are doing things
right. Most HAM's don't. When Mr. Smith imagines doing this he does it
wrong.


He's right, too. My sloper is resonant but I still use a tuner to
protect the transceiver. I was going to use the Remote Autotuner but
don't need it. I get a decent match even on 160.

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

Dave wrote:

...
A tuner at the antenna is a much better setup. You are doing things
right. Most HAM's don't. When Mr. Smith imagines doing this he does it
wrong.


He's right, too. My sloper is resonant but I still use a tuner to
protect the transceiver. I was going to use the Remote Autotuner but
don't need it. I get a decent match even on 160.

Actually, Telemundo is just the same old idiot, pulling the same old
tricks and attempting to appear as a guru to those possessing even less
knowledge than himself ...

I never even commented on where the placement of the matchbox would be,
and, as everyone knows, anywhere along the line you can place it. The
best place would be between the coax (feedline) and the antenna--that
is, taking for granted that the match from your rig to the feedline is
perfect.

However, no matter where you place the matchbox (including up telemundos
butt), its' losses remain constant, and, it is a net loss to the system
.... and the poor antenna remains just as poor--its' faults having been
masked.

Next end-run please?

Regards,
JS

The Difference Between : Shortwave Radio Listener (SWL) -and- AmateurRadio Operators (Hams)
 

On Dec 28, 12:14*pm, John Smith wrote:
RHF wrote:
On Dec 27, 7:46 pm, John Smith wrote:
wrote:

Well, sure, but what does transmitting have to do with
anything? We are not talking about transmitting.
* ...

It has EVERYTHING to do with it, it is the same communication, both
ways, simply in reverse ... like I have stated before, the exact same
laws of physics governing the antenna makes it equally acceptable to
both transmitting and receiving. *The same pattern seen in the signal
transmitted will be seen in the signal(s) received.

- Your argument is the equivalent to arguing that
- a car designed to go forward would not be
- acceptable when backing up ...
- simply ridiculous!
-
- Regards,
- JS

JS -think-about-it-

IF 'by-design' the Car is in-fact designed
to go "Only" Forward :
* It may 'only' have Forward Gears and
a Transmission that has NO Reverse.
* No Rear Window
* No Rear Mirror
NOT So Ridiculous ~ RHF
http://www.prweb.com/prfiles/2006/10...onmeteor72.jpg
*.
Just an Example of "Single Focus" Thinking :
Optimizing Your Results For One Purpose.

Sort of what Shortwave Radio Listeners (SWL)
do when they consider how they are going to
Design, Build and Use an Antenna for the
Hobby of Shortwave Radio Listening *(SWLing)

Yes as you have pointed out : There is a Greater
Boby of Knowledge and Practicum Out There
That Could Be Considered and Used -but- The
Shortwave Listener (SWL) often is 'selective' in
what they consider and use to achieve their
specific limited goals.

It Has To Do With "Level-of-Involvement" :
* Many/Most Amateur Radio Operators {Hams}
have the well earn knowledge and experience
to function 'like' an Auto Mechanic -wrt- Cars
* * Hams at their best are Advocates of the
Technology [ Practicers of The Craft ]
* Many/Most Shortwave Radio Listeners (SWLs)
simply enjoy a level of knowledge and experience
to function 'like' a Car Driver -wrt- Cars
* * SWLs at their best are Hobbyists Enjoyers
of the Technology [ Users of the Technology ]
TBL : Both are Need -and- Both are Different

~ RHF
*.

I see you are ready to go to extraordinary lengths to justify your
statements or propose "special cases" which are only correct in extreme
circumstances of very limited parameters--this is all fine, however,
carry on without me ...

Again, it is as true as when I originally stated it, the same antenna,
its efficiency, fitness-for-purpose, pattern delivered, etc. will work
the same, both forward (transmitting), or in reverse (receiving.) *I am
sure there exists the possiblily of "breaking" or "orchastrating" the
antenna physics to bring about a special case or cases ... no practical
use I have yet seen has required this.

Many hams wish to think themselves "special" because of their hobby, now
you have brought me to the realization that there is the equivalent in
the SWL'ers hobby ... to me, it just looks like one of my other hobbies,
like tropical fish, for example.

Regards,
JS

JS - You started using 'Car' Analogy; and
I followed through with 'Car' Analogy ~ RHF

To many/most Hobbyists there 'hobbies are simply
"Hobbies" : Some thing that they do in their spare
time to enjoy and pass the time. Most Shortwave
Radio Listeners (SWL) fit into this Category of
Hobbyists.

For some/many Hobbyists there 'hobby' is their true
"Avocation" in-fact for some Their HOBBY is Their
Life : Some thing that They Do All The Time : They
Live and Breath Their Hobby : Many Amateur Radio
Operators {Hams} fit into this Category of HOBBYISTS.
http://www.answers.com/Avocation

This is Why I refer to Amateur Radio as "The Craft" :
The Mastery* of the Body of Knowledge and Practices
related to the Science and Art of Radio Operating.
* All Praise Be To Them That Do.
-but- that is not me : for i remain simply a plain old
shortwave radio listener : who keeps his swling
"k-i-s-a-p" = keep/ing it simply and practical

If some one asks "Where To Buy" :
I tell them 'where to buy'.

If some one asks "How To" {Build It} :
I tell them 'how to' {build it}
They Did Not Ask for "The Theory Behind It"
-and- i don't give them 'the theory behind it'

If some asks "What Do You "Recommend" :
I 'recommend' a something or two and usually
provide a few links as pointers to get them going.

hey it is just my opinion and nothing more - kisap ~ RHF
-ps- JS Yes You Are Right "I Am Extremely Special" ;-}

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

John Smith wrote:

...
Actually, Telemundo is just the same old idiot, pulling the same old
tricks and attempting to appear as a guru to those possessing even less
knowledge than himself ...

I never even commented on where the placement of the matchbox would be,
and, as everyone knows, anywhere along the line you can place it. The
best place would be between the coax (feedline) and the antenna--that
is, taking for granted that the match from your rig to the feedline is
perfect.

However, no matter where you place the matchbox (including up telemundos
butt), its' losses remain constant, and, it is a net loss to the system
... and the poor antenna remains just as poor--its' faults having been
masked.

Next end-run please?

Regards,
JS

Now, let me give you a mechanical example, so those willing and/or able
may grasp the concept, in fact, let me give you a couple:

1) The neighbors light is shining in my window(s), it is too bright too
sleep--I place a thick blanket over the window--WAALAA, "masked" the
problem!

2) The neighbors stereo is too loud. I plug my ears, again, WAALAAA,
problem fixed!

3) [add your own example here]

telemundo is an argumentative idiot with a poor working knowledge of
what discussions he engages in ... :-(

But then, if you don't possess the knowledge/experience to be able to
realize this, no one can blame you for being fooled ... later.

Regards,
JS

The Difference Between : Shortwave Radio Listener (SWL) -and-Amateur Radio Operators (Hams)
 

RHF wrote:

[stuff]

RHF, I have no bone to pick with you, don't fall victim to trolls here
which just wish to "stir up chit", to mask their ignorance ...

I had a chit load of ignorance (still do in many areas, including this
one!), you don't know until you do ... we are all here on differing
levels, we can all get along. When Roy, Cecil and others make
statements, I LISTEN, may not understand it, but I listen! :-)

I understand; trust me, you have done nothing to either make me like
you, or not ... that may or may not come later.

Now, this discussion continues ...

Warm regards,
JS

Antenna for shortwave reception
 

In article ,
Dave wrote:

John Smith wrote:
wrote:


Well, sure, but what does transmitting have to do with
anything? We are not talking about transmitting.
...

It has EVERYTHING to do with it, it is the same communication, both
ways, simply in reverse ... like I have stated before, the exact same
laws of physics governing the antenna makes it equally acceptable to
both transmitting and receiving. The same pattern seen in the signal
transmitted will be seen in the signal(s) received.

Your argument is the equivalent to arguing that a car designed to go
forward would not be acceptable when backing up ... simply ridiculous!

Regards,
JS
How does one transmit MW with a ferrite bar antenna?

An MW ferrite antenna:
Transmit antenna rating poor.
Coffee mug warmer rating excellent.

--
Telamon
Ventura, California

Shortwave Radio Listener (SWL) Antennas -versus- Amateur Radio Antennas
 

In article ,
John Smith wrote:

Telamon wrote:

...
Yeah but we don't care about transmitting goofball, we care about
receiving and so that statement "A random wire (e.g. inverted L)
transmits nicely if you use a tuner at the feed point" by Dave is
relevant where you are not.


You ridiculous fool. You are the most complete brain dead example of a
sub-human which has ever been presented to me ...

You dumb twit. We don't care about transmitting.

Receiving is EQUALLY as important as the transmitting element in the
above.

Again you dumb twit, we don't care about transmitting.

Or, to explain it to the necessary point, for a mental midget, such
as yourself: "If the signal being transmitted is low power, or there
are bad conditions, and, perhaps, the guy is in Australia, I'd better
have the "best" antenna possible. However, if I am receiving the
"50,000 watt atmosphere burner", 50 miles away, a rusty coat-hanger,
most likely, would work ..."

You are one funny guy I'll give you that.

However, you mileage may vary with you "magical antenna logic!" grin

The only magic around here is spouted by you. Your experience is
"magically" different than anyone else's and your antenna theory is
simplistic at best not to mention the great job you do of putting words
in peoples mouthes never spoken but what else can we expect from the
comprehension impaired.

I'll tell you what is "magical" and that's the conversations you seem to
have in your head before you post.

You hit me as a guy attempting to pass off "magical physics" to
kindergarten-ers; but then, even that is, most likely, a challenge for
you ... sad, so very, very sad ... :-(

Yeah, very sad of you to keep plonking and then continue to read me.

What a goofball.

--
Telamon
Ventura, California

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

Telamon wrote:
In article ,
Dave wrote:

John Smith wrote:

However, in side-by-side comparisons on 10-6-2m antennas I have built,
comparing a 5/8 against the 1/2 (construction methods/materials and
matching components identical) ... the actual difference, in the real
world, must be less than the width of a meter needle in the readings ...
or, put simply, I no longer deal with the extra length required of the
5/8 ... your mileage may vary ...

The advantage of a physical height (antenna length) between 180 and 215
degrees (see previous post regarding the magic number being around 195
degrees) is improved take-off angle and reduced skywave-groundwave
interaction, not dramatic nearfield voltage increases.

Regarding Mr. Smith's comments above my experience and others is the
opposite. 5/8 is a much better performing antenna than a 1/2 wave for
local VHF and UHF communications. Well worth the effort to build a 5/8
wave antenna over a 1/2 wave. The 5/8 had some kind of series load coil
part way up the whip where the 1/2 wave match/compensation was done at
the base so the whip was solid. Sorry I can't more specific then that as
those experiments were many years ago.

Mr. Smith is still lost in space.


5/8 wavelength antennas do not require a ground plane, do they?

Shortwave Radio Listener (SWL) Antennas -versus- Amateur Radio Antennas
 

In message , Dave
writes
Telamon wrote:
In article ,
Dave wrote:

John Smith wrote:

However, in side-by-side comparisons on 10-6-2m antennas I have
built, comparing a 5/8 against the 1/2 (construction
methods/materials and matching components identical) ... the actual
difference, in the real world, must be less than the width of a
meter needle in the readings ... or, put simply, I no longer deal
with the extra length required of the 5/8 ... your mileage may vary ...

The advantage of a physical height (antenna length) between 180 and
215 degrees (see previous post regarding the magic number being
around 195 degrees) is improved take-off angle and reduced
skywave-groundwave interaction, not dramatic nearfield voltage increases.
Regarding Mr. Smith's comments above my experience and others is the
opposite. 5/8 is a much better performing antenna than a 1/2 wave for
local VHF and UHF communications. Well worth the effort to build a 5/8
wave antenna over a 1/2 wave. The 5/8 had some kind of series load
coil part way up the whip where the 1/2 wave match/compensation was
done at the base so the whip was solid. Sorry I can't more specific
then that as those experiments were many years ago.
Mr. Smith is still lost in space.


5/8 wavelength antennas do not require a ground plane, do they?

Oh yes they do.
--
Ian

The Difference Between : Shortwave Radio Listener (SWL) -and-Amateur Radio Operators (Hams)
 

RHF wrote:


This is Why I refer to Amateur Radio as "The Craft" :
The Mastery* of the Body of Knowledge and Practices
related to the Science and Art of Radio Operating.
* All Praise Be To Them That Do.
-but- that is not me : for i remain simply a plain old
shortwave radio listener : who keeps his swling
"k-i-s-a-p" = keep/ing it simply and practical

I enjoy sending intelligence from point A to point B without wires. I
enjoy making spikes (not Xmas trees) on my FSH-313. My work involves
UHF FM transmitters of between 10 mW and 250 mW. These need to go
300-500 feet (flawlessly). This is very similar to my hobby (what I
enjoy). I can't believe they pay me to do this.

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

John Smith wrote:


Now, let me give you a mechanical example, so those willing and/or able
may grasp the concept, in fact, let me give you a couple:

1) The neighbors light is shining in my window(s), it is too bright too
sleep--I place a thick blanket over the window--WAALAA, "masked" the
problem!

2) The neighbors stereo is too loud. I plug my ears, again, WAALAAA,
problem fixed!

3) [add your own example here]

telemundo is an argumentative idiot with a poor working knowledge of
what discussions he engages in ... :-(

But then, if you don't possess the knowledge/experience to be able to
realize this, no one can blame you for being fooled ... later.

Regards,
JS
Telemundo is a subsidiary of General Electric.

Your analogies don't hold up. You cannot transmit with a Beveridge and
you cannot transmit with a ferrite loop.

The Difference Between : Shortwave Radio Listener (SWL) -and-Amateur Radio Operators (Hams)
 

On Dec 28, 8:38*pm, Telamon
wrote:
In article ,
*John Smith wrote:

RHF wrote:

[stuff]

RHF, I have no bone to pick with you, don't fall victim to trolls here
which just wish to "stir up chit", to mask their ignorance ...

SNIP

- Now that is funny. One Trolling idiot posting
- a response to another trolling idiot "don't fall
- victim to the Trolls".
-
- --
- Telamon
- Ventura, California

Ah Telamon - You know me all too well ~ RHF

The Difference Between : Shortwave Radio Listener (SWL) -and-Amateur Radio Operators (Hams)
 

On Dec 29, 5:50*am, Dave wrote:
RHF wrote:

This is Why I refer to Amateur Radio as "The Craft" :
The Mastery* of the Body of Knowledge and Practices
related to the Science and Art of Radio Operating.
* All Praise Be To Them That Do.
-but- that is not me : for i remain simply a plain old
shortwave radio listener : who keeps his swling
"k-i-s-a-p" = keep/ing it simply and practical

- I enjoy sending intelligence from point A to point B without wires.
*I
- enjoy making spikes (not Xmas trees) on my FSH-313. *My work
involves
- UHF FM transmitters of between 10 mW and 250 mW. These need to go
- 300-500 feet (flawlessly).
-*This is very similar to my hobby (what I enjoy).
-*I can't believe they pay me to do this.

Dave - You Are One of The Lucky Ones. - enjoy ~ RHF

The Difference Between : Shortwave Radio Listener (SWL) -and-Amateur Radio Operators (Hams)
 

RHF wrote:
On Dec 29, 5:50 am, Dave wrote:
RHF wrote:

This is Why I refer to Amateur Radio as "The Craft" :
The Mastery* of the Body of Knowledge and Practices
related to the Science and Art of Radio Operating.
* All Praise Be To Them That Do.
-but- that is not me : for i remain simply a plain old
shortwave radio listener : who keeps his swling
"k-i-s-a-p" = keep/ing it simply and practical
- I enjoy sending intelligence from point A to point B without wires.
I
- enjoy making spikes (not Xmas trees) on my FSH-313. My work
involves
- UHF FM transmitters of between 10 mW and 250 mW. These need to go
- 300-500 feet (flawlessly).
- This is very similar to my hobby (what I enjoy).
- I can't believe they pay me to do this.

Dave - You Are One of The Lucky Ones. - enjoy ~ RHF
.

I do. Thanks.

"Loop Antennas" WebPage -by- James Dale {Mike Bates}
 

On Dec 28, 7:54*pm, Telamon
wrote:
In article ,



*Dave wrote:
John Smith wrote:
wrote:

Well, sure, but what does transmitting have to do with
anything? We are not talking about transmitting.
* ...

It has EVERYTHING to do with it, it is the same communication, both
ways, simply in reverse ... like I have stated before, the exact same
laws of physics governing the antenna makes it equally acceptable to
both transmitting and receiving. *The same pattern seen in the signal
transmitted will be seen in the signal(s) received.

Your argument is the equivalent to arguing that a car designed to go
forward would not be acceptable when backing up ... simply ridiculous!

Regards,
JS
How does one transmit MW with a ferrite bar antenna?

- An MW ferrite antenna:
- Transmit antenna rating poor.
- Coffee mug warmer rating excellent.
-
- --
- Telamon
- Ventura, California

Telamon - Ah listening to the Early Morning Farm
"AG" Report on the AM Radio KMJ 580 kilo-cycles
with a Warm Mug of Coffee. - most excellent ~ RHF
KMJ 580 AM RADIO = http://www.kmj580.com/

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

On Dec 27, 12:57*pm, John Smith wrote:
Billy Burpelson wrote:
...
Say what?

He said he "ain't here to be a ham", so why would he want to transmit?

Well, consider me a "different type of ham." *In that, I always
construct my antennas to receive the best signal for the application at
hand, ALWAYS--transmitting is only a secondary consideration. *As, I
have never found an antenna which has been found to receive the most
efficiently fail to do so in xmit mode. *Given both xmitter and receiver
have the same input impedances ...

I do, frequently, see hams adjust the antenna, and its' type, for the
xmitter--and the best readings which can be obtained in that mode. *I
pay far more attention to how the antenna receives ... I can always
crank up power on this end, should I ever find it necessary--I don't
know what the guys capabilities on the other end is/are ...

Regards,
JS

JS,

Good Antenna Building Concept :
You Can't Talk To Them -unless-
You Can First Hear Them. ~ RHF

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

On Dec 28, 6:24*pm, Dave wrote:
Telamon wrote:
In article ,
*Dave wrote:

Telamon wrote:
In article ,
*Dave wrote:

RHF wrote:

Dave,

IIRC a good Amateur Radio 1/4 WL Vertical-Up-Leg
by 1/4 WL Horizontal-Out-Arm {Inverted "L" Antenna
requires very little Tuning and performs very well near
and far on the HF Band that it is 'cut' to use on.
Using a direct-connect or 1:1 UnUn at the Feed-Point
* Half-Wave Inverted "L" Antenna : 1/4 WL + 1/4 WL

Where-as the more common Shortwave Listener (SWL)
type of {Random Wire} Inverted "L" Antenna is un-equal
and usually has a shorter Vertical-Up-Leg and a longer
Horizontal-Out-Arm of at least 1V-to-2H and often
1V-to-3H or more. *Using a 9:1 Matching Transformer
and Ground Rod at the Feed-Point which is at the base
of the Vertical-Up-Leg.

"Random" implies otherwise. *Instead of a 9:1 UnUn, imagine one of these
at the feed point:

http://www.mfjenterprises.com/Produc...ductid=MFJ-927

I enjoy playing with these kind of things. *So I got a license to
transmit. *Some call that "elitist", I call it self-indulgent.

I would just call it following your interests.

Remote tuners are the right way to do things. Much better than a tuner
in the shack.

A tuner in the shack matches the radio to the transmission line. *There
is still a mismatch at the feedpoint.

Exactly. Then the transmit energy ends up heating the coax to the
antenna and components in the tuner. sarcasm on As a bonus you get RFI
in the shack. Another bonus is high voltage at points in the coax to the
antenna where you could have a flashover condition. Sarcasm off

A tuner at the antenna is a much better setup. You are doing things
right. Most HAM's don't. When Mr. Smith imagines doing this he does it
wrong.

- He's right, too. *My sloper is resonant but
- I still use a tuner to protect the transceiver.
-*I was going to use the Remote Autotuner but
- don't need it. *I get a decent match even on 160.

-IF- Your main objective is to protect the Transceiver
-then- a Tuner in the Radio-Shack will do that.
-however- If your main objective is to 'optimize' your
Transmitting Signal : Then a Tuner at the Antenna's
Feed-Point will do that better. ~ RHF

The Characteristically 50 Ohm Impedance Coax Cable is 'only' 50 OhmsNominal when . . .
 

On Dec 28, 8:36*pm, Telamon
wrote:
In article ,
*John Smith wrote:

SNIP

I never even commented on where the placement of the matchbox would be,
and, as everyone knows, anywhere along the line you can place it. *The
best place would be between the coax (feedline) and the antenna-

Right. That's because you are to stupid to understand a concept until
someone rubes your nose in it. This would not even occur to you until
someone else brought it up.

-that is, taking for granted that the match from your rig to the
feedline is perfect.

SNIP

You are really worried about the match of 50 ohm *coax to your radios 50
ohm output? Now that's funny.

--
Telamon
Ventura, California

IIRC - The Characteristically 50 Ohm Impedance
Coax Cable is 'only' 50 Ohms nominal . . .
Until you attach something to it.

-IF- You attach the nominal 50 Ohm Impedance
of a Transmitter to one end of the Coax Cable the
'other' end will still be about 50 Ohms.
- - - What the Antenna will see.

However -if- You attach an Unknown "Z" Antenna
and Ground to one end of the Coax Cable then the
'other' end may will be near or far from 50 Ohms.
- - - What the Transmitter will see.

Unknown "Z" Antenna = Random Wire Antenna

as always . . . i may be 'w-r-o-n-g' - iane ~ RHF

Shortwave Radio Listener (SWL) Antennas -versus- Amateur Radio Antennas
 

In article ,
Dave wrote:

Telamon wrote:
In article ,
Dave wrote:

John Smith wrote:

However, in side-by-side comparisons on 10-6-2m antennas I have built,
comparing a 5/8 against the 1/2 (construction methods/materials and
matching components identical) ... the actual difference, in the real
world, must be less than the width of a meter needle in the readings ...
or, put simply, I no longer deal with the extra length required of the
5/8 ... your mileage may vary ...

The advantage of a physical height (antenna length) between 180 and 215
degrees (see previous post regarding the magic number being around 195
degrees) is improved take-off angle and reduced skywave-groundwave
interaction, not dramatic nearfield voltage increases.

Regarding Mr. Smith's comments above my experience and others is the
opposite. 5/8 is a much better performing antenna than a 1/2 wave for
local VHF and UHF communications. Well worth the effort to build a 5/8
wave antenna over a 1/2 wave. The 5/8 had some kind of series load coil
part way up the whip where the 1/2 wave match/compensation was done at
the base so the whip was solid. Sorry I can't more specific then that as
those experiments were many years ago.

Mr. Smith is still lost in space.


5/8 wavelength antennas do not require a ground plane, do they?

They need some kind of ground plane. That can be the body of a vehicle.
At a permanent site radials would be used for a raised antenna.

--
Telamon
Ventura, California

The Characteristically 50 Ohm Impedance Coax Cable is 'only' 50 Ohms Nominal when . . .
 

In article
,
RHF wrote:

On Dec 28, 8:36*pm, Telamon
wrote:
In article ,
*John Smith wrote:

SNIP

I never even commented on where the placement of the matchbox would be,
and, as everyone knows, anywhere along the line you can place it. *The
best place would be between the coax (feedline) and the antenna-

Right. That's because you are to stupid to understand a concept until
someone rubes your nose in it. This would not even occur to you until
someone else brought it up.

-that is, taking for granted that the match from your rig to the
feedline is perfect.

SNIP

You are really worried about the match of 50 ohm *coax to your radios 50
ohm output? Now that's funny.


IIRC - The Characteristically 50 Ohm Impedance
Coax Cable is 'only' 50 Ohms nominal . . .
Until you attach something to it.

SNIP

Nope. The cable itself has a characteristic impedance of some design
value. The spacing and size of the conductors along with the dielectric
constant of the insulator between them dictates the impedance of the
coax.

You are confusing the characteristic impedance of the coax with its
ability to be an effective transmission line. The coax only behaves as
an effective transmission line when both ends of it are terminated at
its characteristic impedance.

--
Telamon
Ventura, California

The Characteristically 50 Ohm Impedance Coax Cable is 'only' 50 Ohms Nominal when . . .
 

In message
,
Telamon writes
In article
,
RHF wrote:

On Dec 28, 8:36*pm, Telamon
wrote:
In article ,
*John Smith wrote:

SNIP

I never even commented on where the placement of the matchbox would be,
and, as everyone knows, anywhere along the line you can place it. *The
best place would be between the coax (feedline) and the antenna-

Right. That's because you are to stupid to understand a concept until
someone rubes your nose in it. This would not even occur to you until
someone else brought it up.

-that is, taking for granted that the match from your rig to the
feedline is perfect.

SNIP

You are really worried about the match of 50 ohm *coax to your radios 50
ohm output? Now that's funny.


IIRC - The Characteristically 50 Ohm Impedance
Coax Cable is 'only' 50 Ohms nominal . . .
Until you attach something to it.

SNIP

Nope. The cable itself has a characteristic impedance of some design
value. The spacing and size of the conductors along with the dielectric
constant of the insulator between them dictates the impedance of the
coax.

You are confusing the characteristic impedance of the coax with its
ability to be an effective transmission line. The coax only behaves as
an effective transmission line when both ends of it are terminated at
its characteristic impedance.

Are you really sure about this sweeping statement? For starters, please
define 'effective'. And are you sure that transmitter output impedances
are 50 ohms (or whatever)?
--
Ian

The Characteristically 50 Ohm Impedance Coax Cable is 'only' 50 Ohms Nominal when . . .
 

In article ,
Ian Jackson wrote:

In message
,
Telamon writes
In article
,
RHF wrote:

On Dec 28, 8:36*pm, Telamon
wrote:
In article ,
*John Smith wrote:

SNIP

I never even commented on where the placement of the matchbox would be,
and, as everyone knows, anywhere along the line you can place it. *The
best place would be between the coax (feedline) and the antenna-

Right. That's because you are to stupid to understand a concept until
someone rubes your nose in it. This would not even occur to you until
someone else brought it up.

-that is, taking for granted that the match from your rig to the
feedline is perfect.

SNIP

You are really worried about the match of 50 ohm *coax to your radios 50
ohm output? Now that's funny.


IIRC - The Characteristically 50 Ohm Impedance
Coax Cable is 'only' 50 Ohms nominal . . .
Until you attach something to it.

SNIP

Nope. The cable itself has a characteristic impedance of some design
value. The spacing and size of the conductors along with the dielectric
constant of the insulator between them dictates the impedance of the
coax.

You are confusing the characteristic impedance of the coax with its
ability to be an effective transmission line. The coax only behaves as
an effective transmission line when both ends of it are terminated at
its characteristic impedance.

Are you really sure about this sweeping statement?

Yes. It is basic transmission line theory. RF energy entering or leaving
a coax line has to be at the same impedance or energy is reflected. That
is a basic rule.

For starters, please define 'effective'.

The word effective was used in the context of the coax meeting its
specifications within reason.

And are you sure that transmitter output impedances are 50 ohms (or
whatever)?

If it is specified to be 50 ohms and it is not then it should find its
way back to the manufacturer for repair or redesign.

--
Telamon
Ventura, California

The Difference Between : Shortwave Radio Listener (SWL) -and-Amateur Radio Operators (Hams)
 

RHF wrote:

...
- Now that is funny. One Trolling idiot posting
- a response to another trolling idiot "don't fall
- victim to the Trolls".
-
- --
- Telamon
- Ventura, California

Ah Telamon - You know me all too well ~ RHF
.

Problem is, telemundo does not use the term "newsnet troll" correctly.

His definition: "newsnet-troll = anyone not agreeing with me or
pointing out inaccuracies in my text."

Quite obviously, most here will appear as a troll, to telemundo ... sad,
so very, very sad. :-(

Regards,
JS

The Difference Between : Shortwave Radio Listener (SWL) -and- Amateur Radio Operators (Hams)
 

In article ,
John Smith wrote:

RHF wrote:

...
- Now that is funny. One Trolling idiot posting
- a response to another trolling idiot "don't fall
- victim to the Trolls".
-

Ah Telamon - You know me all too well ~ RHF
.

Problem is, telemundo does not use the term "newsnet troll" correctly.

His definition: "newsnet-troll = anyone not agreeing with me or
pointing out inaccuracies in my text."

That is just a comprehension impaired interpretation.

Quite obviously, most here will appear as a troll, to telemundo ... sad,
so very, very sad. :-(


You have a great imagination but you don't know how to usefully apply it.

--
Telamon
Ventura, California

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

RHF wrote:

...
JS,

Good Antenna Building Concept :
You Can't Talk To Them -unless-
You Can First Hear Them. ~ RHF
.

Well, I'd like an antenna like this one (see URL, below.) He comes into
my location in the low valley of CA like a door buster, from his secret
location in NV. Jumping the high Sierra Mountains in a single leap! grin

http://www.smeter.net/w6obb/antenna-farm.php

Regards,
JS

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

Dave wrote:

...
Your analogies don't hold up. You cannot transmit with a Beveridge and
you cannot transmit with a ferrite loop.


You CAN transmit with both.

And, only emphasizes the importance of what I have been saying, most
would pick the most efficient possible antenna--both examples, of yours,
are less than most efficient ... even for receiving, the ferrite
loop-stick on an a AM/MW radio is far from first choice ... it is
convenient, cheap and highly-portable, however.

Regards,
JS

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

RHF wrote:

[...]

Anyway you cut it ... a matchbox never will improve the performance of a
poor antenna, increase the capture area of a poor antenna, etc.

It will MASK that antennas' short-comings ... same as sweeping dirt
under a rug (notice, another mechanical analogy to the above.)

Regards,
JS

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

Dave wrote:

...
5/8 wavelength antennas do not require a ground plane, do they?

Yeah, in my experience, a vertical 5/8 will require the same as would be
necessary for a 1/4 vertical ... the 1/2 is nice in that advantage, only
requiring a minimal counterpoise.

A few I have seen articles and pictures from, swear the 5/8 beats out
the 1/2--I simply have not found that in actually comparisons. However,
in such situations, I suspect it may be something I am doing wrong, but
for the life of me, I can't find what it could be ... and, it SHOULD
produce a superior radiation pattern for my uses.

And, in a homebrew omni antenna for my 2.4Ghz router, I went 5/8,
mounted ~20ft. in the air, it works well.

Regards,
JS

The Characteristically 50 Ohm Impedance Coax Cable is 'only' 50 Ohms Nominal when . . .
 

In message
,
Telamon writes
In article ,
Ian Jackson wrote:

In message
,
Telamon writes
In article
,
RHF wrote:

On Dec 28, 8:36*pm, Telamon
wrote:



You are confusing the characteristic impedance of the coax with its
ability to be an effective transmission line. The coax only behaves as
an effective transmission line when both ends of it are terminated at
its characteristic impedance.

Are you really sure about this sweeping statement?

Yes. It is basic transmission line theory. RF energy entering or leaving
a coax line has to be at the same impedance or energy is reflected. That
is a basic rule.

For starters, please define 'effective'.

The word effective was used in the context of the coax meeting its
specifications within reason.

If the source and load impedances are NOT the same as the characteristic
impedance of the coax, any 'ineffectiveness' as a transmission line will
not as a result of the coax not meeting its specifications. You simply
haven't used coax with the RIGHT specifications.

And are you sure that transmitter output impedances are 50 ohms (or
whatever)?

If it is specified to be 50 ohms and it is not then it should find its
way back to the manufacturer for repair or redesign.

Indeed, the specs for transmitters do sometimes say that the output
impedance is 50 ohms. This is almost certainly wrong. What it really
means is that the transmitter is designed to work into a 50 ohm load.
The two are rarely the same. Transmitters are designed for best
efficiency and/or linearity. The actual output impedance is not really
relevant. [Signal generators are different. They SHOULD be 50 ohms. This
subject has been discussed ad nauseam in several NGs.]
--
Ian

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

Here's why antenna efficiency is important for transmitting but not for
HF receiving.

First, the definition of efficiency: For a transmitting antenna, it's
the fraction of the power applied which is radiated. The remainder is
turned into heat. For receiving, it's the ratio of the power which is
delivered to the receiver to the power which could be delivered to the
receiver if the antenna had no loss. The efficiency of a given antenna
is the same when transmitting and receiving. Sometimes people use
"efficiency" to mean other things -- this is the meaning of the term in
all antenna literature and texts.

Consider this communications system:

transmitter - antenna - propagation path - antenna - receiver - listener

A receiver unavoidably adds noise to the received signal. So if no noise
is injected in the propagation path, the signal/noise ratio is the ratio
of the signal entering the receiver to the noise created by the
receiver's input circuitry. This is generally the case at VHF and above.

When receiver noise dominates, as above, increasing the receive
antenna's efficiency increases the signal arriving at the receiver, so
the signal/noise ratio improves. This allows you to hear the signal
better. But it only works for VHF and above.

HF is a different story. At HF, there's a lot of atmospheric noise
(injected in the "propagation path" part of the system), and unless the
receive antenna and receiver are exceptionally bad, the atmospheric
noise is much greater than the noise created by the receiver. I
mentioned a simple test in my last posting, to see whether this is the
case -- just disconnect the antenna. If the noise level drops,
atmospheric noise dominates. It's not hard to make a receiver that
atmospheric noise will dominate with a 3 foot whip antenna at HF. So at
HF where atmospheric noise dominates, the signal/noise ratio is the
ratio of the signal entering the receiver to the atmospheric noise
entering the receiver. Compare this to the situation described above for
higher frequencies.

Now let's see what happens when we improve the efficiency of an HF
receiving antenna. Because both the signal and the dominant noise come
from locations in front of (that is, on the transmit side of) the
antenna, improving the efficiency of the antenna makes both the signal
and noise greater in the same proportion when they arrive at the
receiver. There's no improvement at all in the signal/noise ratio. The
effect is the same as turning up the receiver volume control. The only
way you can improve the signal/noise ratio is to somehow favor one over
the other, such as by making the antenna directional. And an
inefficient, directional antenna like a Beverage or small loop will
nearly always enable you to hear better in some directions than an
efficient, nondirectional antenna because directionality helps and
inefficiency doesn't hurt.

How about transmit antenna efficiency?

The signal strength from the transmit antenna is proportional to the
antenna's efficiency. (It also depends on other things, but I'm just
talking about efficiency here.) So if the efficiency of the transmit
antenna increases from, say, 33% to 66%, the power levels of the signals
at the receive antenna and the receiver double, and there's no change to
the received noise, on either HF or VHF and above. So improving the
transmit antenna efficiency always improves the signal/noise ratio at
the receiver, in this case by 3 dB.

That's why you can hear bunches of HF stations with a very inefficient
antenna, but they won't hear you if you try to transmit using that same
antenna -- it's because the noise is injected into the system between
you. And it's likely that you'll be able to hear stations just as well
with the very inefficient antenna as with a much larger, efficient one.

Roy Lewallen, W7EL

The Characteristically 50 Ohm Impedance Coax Cable is 'only' 50 Ohms Nominal when . . .
 

In article ,
Ian Jackson wrote:

In message
,
Telamon writes
In article ,
Ian Jackson wrote:

In message
,
Telamon writes
In article
,
RHF wrote:

On Dec 28, 8:36*pm, Telamon
wrote:



You are confusing the characteristic impedance of the coax with its
ability to be an effective transmission line. The coax only behaves as
an effective transmission line when both ends of it are terminated at
its characteristic impedance.

Are you really sure about this sweeping statement?

Yes. It is basic transmission line theory. RF energy entering or leaving
a coax line has to be at the same impedance or energy is reflected. That
is a basic rule.

For starters, please define 'effective'.

The word effective was used in the context of the coax meeting its
specifications within reason.

If the source and load impedances are NOT the same as the characteristic
impedance of the coax, any 'ineffectiveness' as a transmission line will
not as a result of the coax not meeting its specifications. You simply
haven't used coax with the RIGHT specifications.

OK. I don't understand your point though. My original reply is that coax
has a characteristic impedance based on its design not what it has for
terminations on either end.

And are you sure that transmitter output impedances are 50 ohms (or
whatever)?

If it is specified to be 50 ohms and it is not then it should find its
way back to the manufacturer for repair or redesign.

Indeed, the specs for transmitters do sometimes say that the output
impedance is 50 ohms. This is almost certainly wrong. What it really
means is that the transmitter is designed to work into a 50 ohm load.

I have to disagree with you here. I work with a lot of test equipment
and if this was true good luck getting anything to work. Signal
generators and amplifiers have to have output impedances that match the
coax impedance or you would not be able to predict how test setups would
work.

The two are rarely the same. Transmitters are designed for best
efficiency and/or linearity. The actual output impedance is not really
relevant. [Signal generators are different. They SHOULD be 50 ohms. This
subject has been discussed ad nauseam in several NGs.]

I don't want to get nauseated then. The arguments to the contrary make
no sense. Signal generators, amplifiers, or transmitters all have to
have the same system impedance or the RF just gets reflected back at the
source, which has to dissipate that additional energy as heat usually.
So you would have to beef up the output devices in the source and you
would be wasting a portion of the RF generated.

--
Telamon
Ventura, California

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

Ian Jackson wrote:

...
There is not a lot of difference between the radiation of a 1/2 wave and
a 5/8 wave vertical antenna.

A 1/2 wave needs something like (typically) an L-match (low-to-high
impedance) at the feedpoint. As the antenna is voltage-fed, you can get
away without much of a ground (plane) system (but it does no harm if you
have one). Also, being voltage-fed, the insulation needs to be good
(especially in wet weather).

A 5/8 wave can be 'loaded' to a 3/4 wave by adding a series inductor.
The match to 50 ohms is pretty good. You do need a good ground (plane).
In the horizontal direction, it has a bit more radiation in the 1/2
wave, but not a lot. Mechanically, a VHF/UHF antenna 5/8 wave is robust,
and can resemble a simple base-loaded whip.

Essentially, you pays your money, you takes your choice.

Yes, my actual "hands-on" bears out your, above, text ...

However, after much experiments with differing form of matching schemes,
I have found a gamma match on 1/2 or 5/8 produces the most efficient
matching scheme I have attempted, others mileage may vary.

The gamma does distort the radiation pattern a bit, and can be seen if
modeled in EZNEC/MMANA-GAL, and it is actually seen in hands-on use, if
you rotate the gamma towards, then away from the station you are
receiving a very slight variation in signal can be seen, usually about a
meter-needles-width ... I consider it a very minor anomaly ... again,
others mileage may vary.

Even in a 160m, 50ft "flagpole" DLM, I constructed, this distortion, by
the gamma, is apparent ... however, it consistently shows up as 1
s-unit in hands-on use. I don't have open enough area around the
antenna to even begin taking measurements with a calibrated FSM, and end
up with anything near meaningful measurements ... indeed, surrounding
structures, homes, vehicles, etc., most-likely, distort the signal(s) to
a greater degree.

Regards,
JS

Shortwave Radio Listener (SWL) Antennas -versus- Amateur RadioAntennas
 

Roy Lewallen wrote:

...
Roy Lewallen, W7EL


YEAH, what he said! LOL

And, I must defer to him, his experience allows nothing less ...

Regards,
JS

5/8 WL Antennas ?
 

RHF wrote:

Dave here is a Picture of a . . .
5/8 WL Ground Plane Antenna

No it isn't.

http://users.belgacom.net/hamradio/s...calantenna.htm

"The "ringostar" based coil:
Is made out of 26 cm of 2,5mm installation wire. Remove the isolation of
the wire and tin with a soldering iron the entire wire. The coil is 1,2
turns and has a diameter of 5 cm. One side is connected to the antenna
and the other side to the boom."
.
Note "Installation Instructions" of 5/8 wave vs 1/4 wave antennas. 1/4
wave verticals require a proper ground plane (radials or sheet metal)
to approximate the other half of a center fed dipole. The 5/8 wave is
already over a half-wave long; no plane required. The coax shield
needs a ground, the antenna doesn't.

http://www.diamondantenna.net/m285.html

http://www.diamondantenna.net/hf6fx.html