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

In article
,
RHF wrote:

On Dec 29, 12:37*pm, Telamon
wrote:
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,

OK -restatement- The "Measured" {by You} 50 Ohm Impedance Coax Cable
is 'only' 50 Ohms nominal* * Until you attach something to it.

-IF- You then attach a Transmitters Output that is a Nominal 50 Ohms
to one end of the Coax Cable and then the 'other' end will still
"Measure*" about 50 Ohms. * This is 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 "Measure*" near or far
from 50 Ohms. * This is what the Transmitter will see.

Unknown "Z" Antenna = Random Wire Antenna

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

You are just confusing a few things. You need to understand that at RF
all parts of a circuit are not "seen" by the RF energy "at the same
time." The energy has to propagate through the circuit. This is
different from DC where the whole circuit "is seen" by the energy
source at once. I'm sure that at DC you are familiar with adding up
resistor networks or loads into a total load resistance where you can
figure out what the total current would be if you applied a certain
voltage. This is also know as a lump sum circuit.

At RF since it takes time for the energy to propagate through parts of
the circuit so they are not seen at the same time and you have to use
vector math that has magnitude and phase components, instead of just
magnitude, to describe the current that results from an applied
voltage. Now with this vector math representing the circuit impedance
as opposed to just magnitude resistance you can make transformations
similar to an equivalent DC total load resistance for RF current
calculations but you have to keep in mind that these are time or phase
dependent. A complication of this is some of the energy can even go
backward depending on the circuit so these time dependent voltages and
currents need to be summed as vectors with magnitude and phase, which
represent a voltage or current at a spot in the circuit.

The practical upshot of this is that RF paths like coax have to be
viewed as transmission lines where the RF energy only "sees" a part of
the coax at any one moment in time and after a short period of time the
energy "sees" the next part of the coax and so on until it reaches the
end. With this understanding it is the "environment" of the coax that
causes it to represent an "impedance" or how it reacts to the RF energy
as a complex resistance to its flow. This reactive environment is
created by the size, spacing, and DC resistance of the two conductors
along with the dielectric value of the insulator between them.

Now with that said you can still make the R total type of RF impedance
calculation with a resistor or a reactive load on the far end of a coax
cable as a total transformed circuit impedance value but it does not
change in any way the intrinsic impedance of the coax itself, which is
fully dependent on its physical construction.

Now, if you are still with me, the coax will only function properly as a
transmission line when the source impedance at one end and the load
impedance at the other end are the same value. In this state all the RF
energy is internal to the coax and if the load or source impedance is
not the same currents start to flow on the outside of the coax so it
will not shield properly. All the energy will not even enter the coax at
the source end and energy will be reflected at the load end creating
standing waves of energy on the coax, which is the sum of the forward
and reverse waves at any one point. Where these waves sum the voltages
can be many times higher than the source causing excessive heating or
even breakdown of the dielectric at that point or arcing at the
connectors. Under these conditions the coax specifications will not be
met. The coax will not meet its isolation, insertion loss, or VSWR
specifications even though there is nothing wrong with it.

--
Telamon
Ventura, California

Transmitting with a "Beverage" Antenna and/or a Ferrite Rod Antenna
 

In article ,
Dave wrote:

RHF wrote:

Dave even Arnie Coro "DXers Unlimited" [RHC]
says it can be done ;-}
http://www.radiohc.org/Distributions...s/01-1222.html
"you can build a ferrite rod loop antenna"
.
all things are 'possible' : especially for the man
who does not know that he can not do it ~ RHF

Arnie Coro also recommends the T2FD.

This is a closed loop type of antenna, which in my opinion is safer than
a single wire connected to a portable as far as static charge on the
single wire blowing the radios front end FET amplifier.

--
Telamon
Ventura, California

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

In article ,
Dave wrote:

Telamon wrote:
In article
,
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.

Here is an example of the 5/8 wavelength antenna I recall using in the
center of the page. The one I used was permanent mount not magnetic
though. The van roof it was installed on was the ground plane.

http://www.new-tronics.com/main/html/mobile_vhf.html

When this antenna was changed for a 1/2 wave a lot of coverage was lost.
This was before cell phones so I had to start using pay phones a lot.


The one with the center coil is a collinear. It is 2 stacked verticals
with a "delay" between.

I don't think it works that way. The coil is just a way to shorten the
total whip length. I haven't looked at the design but I would be
surprised if what you posted was true.

--
Telamon
Ventura, California

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

In article ,
"RP" wrote:

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.

We don't...?

Yeah we don't. This was posted in the shortwave group and cross posted
to the amateur group.

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

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

We don't...?

Yes we don't care.

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

I thought this was your trick?

No not mine although filters do get turned off from time to time for
various reasons.

What a goofball.

Takes one to know one.

And that make you one now doesn't it.

--
Telamon
Ventura, California

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

In article ,
John Smith wrote:

RP wrote:
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.

We don't...?

Receiving is EQUALLY as important as the transmitting element in the
above.
Again you dumb twit, we don't care about transmitting.

We don't...?

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

I thought this was your trick?

What a goofball.

Takes one to know one.



Hey, telemundo is a great man, in his own mind, leave him alone ...
humor here is sparse, he provides for a needed demand ... :-)

You are just a comprehension impaired fool that talks to himself. How
you doing today? Have any nice conversations with yourself you would
like to share with the newsgroup?

--
Telamon
Ventura, California

MatchBoxes Do They Work ? -aka- Improve Your Effective RadiatedPower ?
 

On Dec 31, 1:34*pm, John Smith wrote:
RHF wrote:
On Dec 29, 1:44 pm, John Smith wrote:
RHF wrote:

[...]

- Anyway you cut it ... a matchbox never will improve
- the performance of a poor antenna,

JS,

- - So you are saying that I have an Antenna and Transceiver
- - and can hear 5 Radio Operators in a Net on a Frequency;
- - but only 2 of them can hear me.

= BAD {Lousy} Poorly "Radiating" Antenna
without the 'matchbox' in the circuit.

- - I then put a MatchBox in-line between my Antenna and
- - Transceiver and Adjust-It; and can still hear all 5 Radio
- - Operators on a Frequency and now all 5 of them can
- - hear me.

= GOOD {Better} Nicely "Radiating" Antenna
with the 'MatchBox' in the circuit.

Once Again 'why' is it that with the MatchBox and the
same Antenna and Transceiver : Now more people can
hear me or hear me better : It the same Poor Antenna

Hey may be MatchBoxs are Super Radiators ? and they
are now hearing me off my MatchBox versus my Poor
Antenna without the 'matchbox'.

- - AGAIN - -
- - To Me That Is Very Real Improved Performance from
- - My Antenna and Transceiver that is a direct result of
- - using the MatchBox between them. ~ RHF
- - *.

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

I guess, any possibly way it can be explained to you, will fail ...

If you introduce an inductance to resonate the antenna, you introduce a
loss, if you introduce a capacitance, the same ... LC or PI networks,
commonly used in matchboxes, have notable losses.

I have a 60ft longwire, mounted ~40 ft. in the air. *Since it is only
physically resonate on but a couple/few freqs, and, since I am not
employing some form of matching on the antenna, and since the antenna
does not, naturally, present a correct impedance to my feedline/rig,
some form of lossy matching must be tolerated ... since the matchbox is
located at my receiver, whatever feedlines I choose will also become a
part of the "antenna." *The ideal placement for a matchbox would be at
the antenna, as everyone is and has been aware of for a long time, or
should have been aware.

As I stated, continue to state, and have no other choice than to state
when worried about being correct--no matchbox will ever improve the
performance of a poor antenna--all it can do is allow you to get maximum
benefit of that poor performance.

You have separate components, affects/effects, terms, etc. all confused
and lumped together. *Antenna design, capture area, etc. effect antenna
efficiency--the impedance that/those designs/constructions entail, and
the method of matching (transforming) that impedance to one acceptable,
is another "thing", all-together.

Regards,
JS

MatchBoxes Do They Work ? -aka- Improve Your Effective Radiated Power ?
 

In article ,
John Smith wrote:

RHF wrote:
On Dec 29, 1:44 pm, John Smith wrote:
RHF wrote:

[...]

- Anyway you cut it ... a matchbox never will improve
- the performance of a poor antenna,

JS,

So you are saying that I have an Antenna and Transceiver
and can hear 5 Radio Operators in a Net on a Frequency;
but only 2 of them can hear me.

I then put a MatchBox in-line between my Antenna and
Transceiver and Adjust-It; and can still hear all 5 Radio
Operators on a Frequency and now all 5 of them can
hear me.

To Me That Is Very Real Improved Performance from
My Antenna and Transceiver that is a direct result of
using the MatchBox between them. ~ RHF
.

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.)



I guess, any possibly way it can be explained to you, will fail ...

If you introduce an inductance to resonate the antenna, you introduce a
loss, if you introduce a capacitance, the same ... LC or PI networks,
commonly used in matchboxes, have notable losses.

I have a 60ft longwire, mounted ~40 ft. in the air. Since it is only
physically resonate on but a couple/few freqs, and, since I am not
employing some form of matching on the antenna, and since the antenna
does not, naturally, present a correct impedance to my feedline/rig,
some form of lossy matching must be tolerated ... since the matchbox is
located at my receiver, whatever feedlines I choose will also become a
part of the "antenna." The ideal placement for a matchbox would be at
the antenna, as everyone is and has been aware of for a long time, or
should have been aware.

As I stated, continue to state, and have no other choice than to state
when worried about being correct--no matchbox will ever improve the
performance of a poor antenna--all it can do is allow you to get maximum
benefit of that poor performance.

SNIP

"all it can do is allow you to get maximum benefit of that poor
performance"

What the hell is this supposed to mean?

My best guess is you can continue to wrong.

--
Telamon
Ventura, California

MatchBoxes Do They Work ? -aka- Improve Your Effective RadiatedPower ?
 

On Dec 31, 5:57*pm, John Smith wrote:
RHF wrote:

* ...



- - So you are saying that I have an Antenna and Transceiver
- - and can hear 5 Radio Operators in a Net on a Frequency;
- - but only 2 of them can hear me.

= BAD {Lousy} Poorly "Radiating" Antenna
without the 'matchbox' in the circuit.

- - I then put a MatchBox in-line between my Antenna and
- - Transceiver and Adjust-It; and can still hear all 5 Radio
- - Operators on a Frequency and now all 5 of them can
- - hear me.

= GOOD {Better} Nicely "Radiating" Antenna
with the 'MatchBox' in the circuit.

Once Again 'why' is it that with the MatchBox and the
same Antenna and Transceiver : Now more people can
hear me or hear me better : It the same Poor Antenna

Hey may be MatchBoxs are Super Radiators ? and they
are now hearing me off my MatchBox versus my Poor
Antenna without the 'matchbox'.

- - AGAIN - -
- - To Me That Is Very Real Improved Performance from
- - My Antenna and Transceiver that is a direct result of
- - using the MatchBox between them. ~ RHF
- - *.
...

As, I have said, the terms you think and communicate in are in error.
Because of preconceived notions you have formed, everything you hear
just brings you back to your previous errors.

Arguing though all that mess would only lead you further astray ... a
matchbox will do NOTHING to improve a poor antenna, whether you are
transmitting on that poor antenna or receiving on that poor antenna ...
once you realize that single point, progress forward will be possible,
end-of-story.

The world is full of "testimonials for a particular antenna(s)", many of
those testimonials are worth less than the paper they are written on.
Combine that with unscrupulous claims, "facts", figures and charts which
has been hoisted on an ignorant public (most famous might be the past
practices of CB antenna manufacturers/suppliers, although you can find
it in other radio venues also) and it is easy to see why so much
confusion exists.

One thing a matchbox is excellent at, getting the maximum amount of
power transferred to a poor antenna--where it will promptly be lost in
heat ... both, in the matchbox and in the feed-line/antenna-components.

Regards,
JS

JS - OK to use your 'words'

This here MatchBox thingee "is excellent at, getting
the maximum amount of power transferred to a poor
antenna"

CONDITION # 1 'Before' the MatchBox thingee :
Less Power Going to the Antenna; which is
Wasted as Heat; with no MatchBox Loses.
-or- Just may be less Power being Effectively
Radiated by the Antenna

JS -what-about- The 'Before' Condition of the Transmitter
with a Poor Antenna and NO MatchBox is IT's Power
Output "Optimum" {Full Power} or may be 'sub-optimum'
some reduced power level due to the Poor Antenna ?

Wouldn't the "maximum amount of power" = Full Power ?
And some thing less be a reduced power level ?

System : Transceiver Coax Cable Antenna
"" Power Out and Reflected Power

CONDITION # 2 'After' the MatchBox thingee :
More Power Going to the Antenna; which is
also Wasted as Heat; with MatchBox Loses.
-or- Just may be More Power being Effectively
Radiated by the Antenna.

JS -what-about- The 'After' Condition of the Transmitter
with a Poor Antenna and using a MatchBox is IT's
Power Output now at "Optimum" {Full Power} with the
MatchBox and the Poor Antenna ?

Wouldn't the "maximum amount of power" = Full Power ?

System : Transceiver Coax Cable MatchBox Antenna
"" Power Out

JS -obtw- What's with these references to CB Radio ?

is the nature of electricity and radio frequencies
and the laws of physics different for amateur and
cb radio two-way communications ? ? ? ~ RHF

MatchBoxes Do They Work ? -aka- Improve Your Effective RadiatedPower ?
 

RHF wrote:

...
JS - OK to use your 'words'

This here MatchBox thingee "is excellent at, getting
the maximum amount of power transferred to a poor
antenna"

CONDITION # 1 'Before' the MatchBox thingee :
Less Power Going to the Antenna; which is
Wasted as Heat; with no MatchBox Loses.
-or- Just may be less Power being Effectively
Radiated by the Antenna

JS -what-about- The 'Before' Condition of the Transmitter
with a Poor Antenna and NO MatchBox is IT's Power
Output "Optimum" {Full Power} or may be 'sub-optimum'
some reduced power level due to the Poor Antenna ?

Wouldn't the "maximum amount of power" = Full Power ?
And some thing less be a reduced power level ?

System : Transceiver Coax Cable Antenna
"" Power Out and Reflected Power

CONDITION # 2 'After' the MatchBox thingee :
More Power Going to the Antenna; which is
also Wasted as Heat; with MatchBox Loses.
-or- Just may be More Power being Effectively
Radiated by the Antenna.

JS -what-about- The 'After' Condition of the Transmitter
with a Poor Antenna and using a MatchBox is IT's
Power Output now at "Optimum" {Full Power} with the
MatchBox and the Poor Antenna ?

Wouldn't the "maximum amount of power" = Full Power ?

System : Transceiver Coax Cable MatchBox Antenna
"" Power Out

JS -obtw- What's with these references to CB Radio ?

is the nature of electricity and radio frequencies
and the laws of physics different for amateur and
cb radio two-way communications ? ? ? ~ RHF
.

You now just wish to produce so much BS that original statements and
facts become confusing, along with readers which you have a chance of
confusing ... all original statements stand ... your attempt to blow up
the "problem" to n'th degrees of magnitude is a tactic most lose with
age, discipline, experience, logic, etc. ... your hunt for a special
case to justify some bizarre anomaly which you might find along the way,
and justify some debate, may interest some ... since I have no need, not me.

Going to extraordinary lengths so that you may regain some bit of
credibility on some minor point is a complete waste of my time--indeed,
it makes a statement about you and your mental state which is blatantly
obvious to those with an understanding of the concepts we have been
discussing, and "have been around the block" ... end-of-story.

Perhaps someone else will finally be able to get through to you, if they
are kind and have the time to waste ... in the meantime, no one attempts
to halt your practices ... have at it big boy. ;-)

Regards,
JS

MatchBoxes Do They Work ? -aka- Improve Your Effective RadiatedPower ?
 

On Dec 31, 8:57*pm, John Smith wrote:
RHF wrote:
...
JS - OK to use your 'words'

This here MatchBox thingee "is excellent at, getting
the maximum amount of power transferred to a poor
antenna"

CONDITION # 1 'Before' the MatchBox thingee :
Less Power Going to the Antenna; which is
Wasted as Heat; with no MatchBox Loses.
-or- Just may be less Power being Effectively
Radiated by the Antenna

JS -what-about- The 'Before' Condition of the Transmitter
with a Poor Antenna and NO MatchBox is IT's Power
Output "Optimum" {Full Power} or may be 'sub-optimum'
some reduced power level due to the Poor Antenna ?

Wouldn't the "maximum amount of power" = Full Power ?
And some thing less be a reduced power level ?

System : Transceiver Coax Cable Antenna
"" Power Out and Reflected Power

CONDITION # 2 'After' the MatchBox thingee :
More Power Going to the Antenna; which is
also Wasted as Heat; with MatchBox Loses.
-or- Just may be More Power being Effectively
Radiated by the Antenna.

JS -what-about- The 'After' Condition of the Transmitter
with a Poor Antenna and using a MatchBox is IT's
Power Output now at "Optimum" {Full Power} with the
MatchBox and the Poor Antenna ?

Wouldn't the "maximum amount of power" = Full Power ?

System : Transceiver Coax Cable MatchBox Antenna
"" Power Out

JS -obtw- What's with these references to CB Radio ?

is the nature of electricity and radio frequencies
and the laws of physics different for amateur and
cb radio two-way communications ? ? ? ~ RHF
*.

You now just wish to produce so much BS that original statements and
facts become confusing, along with readers which you have a chance of
confusing ... all original statements stand ... your attempt to blow up
the "problem" to n'th degrees of magnitude is a tactic most lose with
age, discipline, experience, logic, etc. ... your hunt for a special
case to justify some bizarre anomaly which you might find along the way,
and justify some debate, may interest some ... since I have no need, not me.

Going to extraordinary lengths so that you may regain some bit of
credibility on some minor point is a complete waste of my time--indeed,
it makes a statement about you and your mental state which is blatantly
obvious to those with an understanding of the concepts we have been
discussing, and "have been around the block" ... end-of-story.

Perhaps someone else will finally be able to get through to you, if they
are kind and have the time to waste ... in the meantime, no one attempts
to halt your practices ... have at it big boy. *;-)

Regards,
JS

JS,

Oh Well I Give Up You Have Worn Me Down: You Clearly
Don't Have The Answer To The Ultimate Question.

hint "42" ~ RHF

MatchBoxes Do They Work ? -aka- Improve Your Effective RadiatedPower ?
 

RHF wrote:

...
JS,

Oh Well I Give Up You Have Worn Me Down: You Clearly
Don't Have The Answer To The Ultimate Question.

hint "42" ~ RHF
.
-ps- Telamon could must likely 'clue-you-in' provided
that you were only willing to listen, think and learn.
.


LOL ...

Regards,
JS

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

"Telamon" wrote in message
...
In article ,
"RP" wrote:

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

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 ...

That's our boy Telamon!

I'm not your boy Mr. Anonymous open news server user.

You're the newsgroup hobo, bum, etc.

Hanging around, pretending you are some authority on something.

You're the newsgroup tramp.

5/8 WL Antennas ?
 

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

Dave wrote:

...
A "counterpoise" is not a ground plane.
...
"Buckets of irony littered the lobby"

Oh no, here we go again with more magical/mystical antenna physics and
supernatural powers ...

SNIP

No, for that we all defer to you anonymous Mr. Assembly-wizard.

Telamon is just too much!

The newgroup Jester!

The Difference Between : Telaturd and real newsgroup users...
 

"Telamon" wrote in message
...
In article ,
"RP" wrote:

"Telamon" wrote in message
...
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".

And the hobo of s.r.sw Teleamon, the biggest troll here....is telling
other
trolls how to act!

Hillarious!

You are just a two bit anonymous posting moron that does not contribute
to the news group in any meaningful way. None care what you post.

Yet you keep reading and responding to all these posts that you claim not to
care about.

Hillarious is right!

You keep reading these people that you say contribute nothing.

Hillarious again!

Some people contribute to the newsgroup simply by pointing out what a turd
you are....making sure others don't step in you.



--
Telamon
Ventura, California

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

In article ,
"Hangman" wrote:

"Telamon" wrote in message
...
In article
,
RHF wrote:

On Dec 29, 12:37 pm, Telamon
wrote:
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,

OK -restatement- The "Measured" {by You} 50 Ohm Impedance Coax Cable
is 'only' 50 Ohms nominal* * Until you attach something to it.

-IF- You then attach a Transmitters Output that is a Nominal 50 Ohms
to one end of the Coax Cable and then the 'other' end will still
"Measure*" about 50 Ohms. * This is 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 "Measure*" near or far
from 50 Ohms. * This is what the Transmitter will see.

Unknown "Z" Antenna = Random Wire Antenna

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

You are just confusing a few things. You need to understand that at RF
all parts of a circuit are not "seen" by the RF energy "at the same
time." The energy has to propagate through the circuit. This is
different from DC where the whole circuit "is seen" by the energy
source at once. I'm sure that at DC you are familiar with adding up
resistor networks or loads into a total load resistance where you can
figure out what the total current would be if you applied a certain
voltage. This is also know as a lump sum circuit.

At RF since it takes time for the energy to propagate through parts of
the circuit so they are not seen at the same time and you have to use
vector math that has magnitude and phase components, instead of just
magnitude, to describe the current that results from an applied
voltage. Now with this vector math representing the circuit impedance
as opposed to just magnitude resistance you can make transformations
similar to an equivalent DC total load resistance for RF current
calculations but you have to keep in mind that these are time or phase
dependent. A complication of this is some of the energy can even go
backward depending on the circuit so these time dependent voltages and
currents need to be summed as vectors with magnitude and phase, which
represent a voltage or current at a spot in the circuit.

The practical upshot of this is that RF paths like coax have to be
viewed as transmission lines where the RF energy only "sees" a part of
the coax at any one moment in time and after a short period of time the
energy "sees" the next part of the coax and so on until it reaches the
end. With this understanding it is the "environment" of the coax that
causes it to represent an "impedance" or how it reacts to the RF energy
as a complex resistance to its flow. This reactive environment is
created by the size, spacing, and DC resistance of the two conductors
along with the dielectric value of the insulator between them.

Now with that said you can still make the R total type of RF impedance
calculation with a resistor or a reactive load on the far end of a coax
cable as a total transformed circuit impedance value but it does not
change in any way the intrinsic impedance of the coax itself, which is
fully dependent on its physical construction.

Now, if you are still with me, the coax will only function properly as a
transmission line when the source impedance at one end and the load
impedance at the other end are the same value. In this state all the RF
energy is internal to the coax and if the load or source impedance is
not the same currents start to flow on the outside of the coax so it
will not shield properly. All the energy will not even enter the coax at
the source end and energy will be reflected at the load end creating
standing waves of energy on the coax, which is the sum of the forward
and reverse waves at any one point. Where these waves sum the voltages
can be many times higher than the source causing excessive heating or
even breakdown of the dielectric at that point or arcing at the
connectors. Under these conditions the coax specifications will not be
met. The coax will not meet its isolation, insertion loss, or VSWR
specifications even though there is nothing wrong with it.



Ole Telamonkey sure is one smart dude. Wow!

Did it make any sense to you goofball or just sound like gobbledegook?

--
Telamon
Ventura, California

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

Telamon has some sense.
Thank You, Pasadena,California for the 2009 New Years Day Parade.Job
Well Done.
cuhulin

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

Brenda Ann is cuter though.
cuhulin

Antenna for shortwave reception
 

flashdrive wrote:

...
This one looks like a good candidate. The data sheet gives a suggested
schematic on page-3. All it needs is the input filter for the MW/HF
range. Not sure about the input/output impedance of that circuit though.

http://www.minicircuits.com/pdfs/GALI-74+.pdf

How about this:

http://cgi.ebay.com/Sirenza-SGA-4586...3286.m20.l1116

(take care with line wrapping of the URL, above)

10 for $10.00 plus $2.50 USD -- comes to $1.25 a piece, and provides for
a fatal error in construction/use.

They are a bit small, sharpen your soldering iron, but should be easily
"do-able."

Regards,
JS

Antenna for shortwave reception
 

John Smith wrote:

...
How about this:

http://cgi.ebay.com/Sirenza-SGA-4586...3286.m20.l1116


(take care with line wrapping of the URL, above)

10 for $10.00 plus $2.50 USD -- comes to $1.25 a piece, and provides for
a fatal error in construction/use.

They are a bit small, sharpen your soldering iron, but should be easily
"do-able."

Regards,
JS

Soldering the device(s) would be similar to this:

http://www.youtube.com/watch?v=kAADF...eature=related

Regards,
JS

Antenna for shortwave reception
 

Dave wrote:

...
The IMD is way worse than the Minicircuits device Telemon referenced.

Telemondo is plonked, here ... :-)

And, would be similar to the device I referenced:

http://www.sirenza.com/documents/pro..._Datasheet.pdf

There is a diagram, on the above sheet, which shows it mounted on an
evaluation board ...

Regards,
JS

Antenna for shortwave reception
 

In article ,
John Smith wrote:

Dave wrote:

...
The IMD is way worse than the Minicircuits device Telemon referenced.

Telemondo is plonked, here ... :-)

You still read my posts.

And, would be similar to the device I referenced:

http://www.sirenza.com/documents/pro..._Datasheet.pdf

There is a diagram, on the above sheet, which shows it mounted on an
evaluation board ...

Why are you using a silicon/germanium RF transistor rated to 5 GHz for
HF? A little overkill there don't you think?

--
Telamon
Ventura, California

Antenna for shortwave reception
 

John Smith wrote:
flashdrive wrote:

...
I referenced the Minicircuits MMIC. I think the specs look pretty good
for a MW/HF loop pre-amp. I wonder if Wellbrook uses a MMIC?

I doubt it. I would think their bottom line would be cost and they
would be using the cheapest components available ...

Regards,
JS

Wellbrook doesn't give off that kind of vibe.

Antenna for shortwave reception
 

John Smith wrote:
Dave wrote:

...
I use these for UHF receiver boosting.

http://www.minicircuits.com/pdfs/HELA-10.pdf

I don't have any need for balanced input/output, nor the cost of
interfacing, the between-lead spacing of .022 in. is out of the
questing, too easy to bridge between pins ... IMHO.

Regards,
JS

I gave you two versions of the same preceison amp, in answer to your
example of a mediocre amp. If the leads are too close together get the
unit in a case, with 50 Ohms in and out.

Telemon is right though, the original thread was about HF, and the 3
term device that the other guys referenced, or even the 3 term device
Ten-Tec used 8 years ago, are superior to your little 40 mW MMIC.

Active 3-30 MHz "Hula-Loop" Antenna for Shortwave
 

On Jan 1, 5:41*pm, flashdrive wrote:
Dave wrote:
John Smith wrote:

John Smith wrote:

...
How about this:

http://cgi.ebay.com/Sirenza-SGA-4586...of-10-RF-Ampli....

(take care with line wrapping of the URL, above)

10 for $10.00 plus $2.50 USD -- comes to $1.25 a piece, and provides
for a fatal error in construction/use.

They are a bit small, sharpen your soldering iron, but should be
easily "do-able."

Regards,
JS

Soldering the device(s) would be similar to this:

http://www.youtube.com/watch?v=kAADF...eature=related

Regards,
JS

The IMD is way worse than the Minicircuits device Telemon referenced.

- I referenced the Minicircuits MMIC.
- I think the specs look pretty good for a MW/HF loop pre-amp.
- I wonder if Wellbrook uses a MMIC?

Why bother with Wellbrook ?

Active 3-30 MHz "Hula-Loop" Antenna for Shortwave
http://www.techlib.com/electronics/antennas.html
The "Loopifier" ! [Loop-I-Fier] -by- Charles Wenzel
Copyright 1995 & Updated 2000

iane ~ RHF

Active 3-30 MHz "Hula-Loop" Antenna for Shortwave
 

RHF wrote:

...
Active 3-30 MHz "Hula-Loop" Antenna for Shortwave
http://www.techlib.com/electronics/antennas.html
The "Loopifier" ! [Loop-I-Fier] -by- Charles Wenzel
Copyright 1995 & Updated 2000

iane ~ RHF
.


His construction of the loop looks workable, feed its' output to a MMIC,
to simplify parts/construction, and you are good to go ...

Regards,
JS

Coax Loop & Active Loop & Mini-Whip Antennas for Shortwave RadioListening (SWL)
 

On Jan 2, 4:37*pm, RHF wrote:
On Jan 1, 5:41*pm, flashdrive wrote:

Dave wrote:
John Smith wrote:

John Smith wrote:

...
How about this:

http://cgi.ebay.com/Sirenza-SGA-4586...of-10-RF-Ampli...

(take care with line wrapping of the URL, above)

10 for $10.00 plus $2.50 USD -- comes to $1.25 a piece, and provides
for a fatal error in construction/use.

They are a bit small, sharpen your soldering iron, but should be
easily "do-able."

Regards,
JS

Soldering the device(s) would be similar to this:

http://www.youtube.com/watch?v=kAADF...eature=related

Regards,
JS

The IMD is way worse than the Minicircuits device Telemon referenced.

- I referenced the Minicircuits MMIC.
- I think the specs look pretty good for a MW/HF loop pre-amp.
- - I wonder if Wellbrook uses a MMIC?

- Why bother with Wellbrook ?
-
- Active 3-30 MHz "Hula-Loop" Antenna for Shortwave
- http://www.techlib.com/electronics/antennas.html
- The "Loopifier" ! [Loop-I-Fier] -by- Charles Wenzel
- Copyright 1995 & Updated 2000
-
- iane ~ RHF
- *.

Magnetna Loop Antena
http://users.triera.net/zupanbra/drm/antena.html
{Passive Coax Cable 'Magnetic" Tuned Loop Antenna}

Aktivna Antena za DRM
http://users.triera.net/zupanbra/drm/antena.html
{Active Broadband Loop Antenna for DRM}

PA0RDT Mini-Whip Antenna
http://users.triera.net/zupanbra/drm/antena.html
http://users.triera.net/zupanbra/pdf/mini-whip_SCH.pdf
http://users.triera.net/zupanbra/pdf/miniwhip_TIV.pdf

shortwave radio reception starts with
your antenna - iane ~ RHF {pomkia}

Antenna for shortwave reception
 

John Smith wrote:
Dave wrote:

...
Wellbrook doesn't give off that kind of vibe.

What kind of "vibes" are you getting from your
Ouji-Board/psychic-abilities about Obama?

Inquiring minds wanna know, ya' know? ;-)

Regards,
JS

He's normal.

Antenna for shortwave reception
 

John Smith wrote:
Dave wrote:

...
I gave you two versions of the same preceison amp, in answer to your
example of a mediocre amp. If the leads are too close together get
the unit in a case, with 50 Ohms in and out.

Telemon is right though, the original thread was about HF, and the 3
term device that the other guys referenced, or even the 3 term device
Ten-Tec used 8 years ago, are superior to your little 40 mW MMIC.

I think the device I gave is easily available and cheap, large enough to
easily solder, etc., and not only that, but it would more than
suffice--I'd say that was nothing short of excellent, acceptable noise
figure also. Me thinks you look for a problem to satisfy more than
actual needs and fitness for duty--your ego possibly?

I just don't see Ghz capabilities being a problem, so why you would
think only requiring HF capabilities from it is any sort of a problem.
Indeed, with switchable filters in front of it, you could use it to scan
for wifi points ...

I suppose I could spend anything I wanted, a $1.25 per unit sounds good
to me ...

Regards,
JS

I deal with multiple carriers in the passband and I have to see an IP3
at least in the upper 30s.

Antenna for shortwave reception
 

John Smith wrote:
Dave wrote:

...
I deal with multiple carriers in the passband and I have to see an IP3
at least in the upper 30s.

Without a doubt, for any possible solution(s) a person(s) could come up
with--a special case(s) could be found to negate fitness for purpose ...

Any good college debate class will quickly teach someone that point--the
first day of class!

Regards,
JS

???

Antenna for shortwave reception
 

On Jan 3, 11:41*am, John Smith wrote:
Dave wrote:
...
I deal with multiple carriers in the passband and I have to see an IP3
at least in the upper 30s.

Without a doubt, for any possible solution(s) a person(s) could come up
with--a special case(s) could be found to negate fitness for purpose ...

- Any good college debate class will quickly teach
- someone that point--the first day of class!
-
- Regards,
- JS

JS,

Sounds like you are a pretty good 'debater' yourself.

maybe you studied under mwb ? ;-} ~ RHF

Antenna for shortwave reception
 

In article ,
Dave wrote:

John Smith wrote:
Dave wrote:

...
I deal with multiple carriers in the passband and I have to see an IP3
at least in the upper 30s.

Without a doubt, for any possible solution(s) a person(s) could come up
with--a special case(s) could be found to negate fitness for purpose ...

Any good college debate class will quickly teach someone that point--the
first day of class!


???

For some people debate is much more important than reality so now you
know where Mr. Smith stands.

--
Telamon
Ventura, California

Antenna for shortwave reception
 

In article
,
RHF wrote:

On Jan 3, 11:41*am, John Smith wrote:
Dave wrote:
...
I deal with multiple carriers in the passband and I have to see an IP3
at least in the upper 30s.

Without a doubt, for any possible solution(s) a person(s) could come up
with--a special case(s) could be found to negate fitness for purpose ...

- Any good college debate class will quickly teach
- someone that point--the first day of class!
-
- Regards,
- JS

JS,

Sounds like you are a pretty good 'debater' yourself.

maybe you studied under mwb ? ;-} ~ RHF
.

So near and yet so far from... never mind.

--
Telamon
Ventura, California

Antenna for shortwave reception
 

Dave wrote:

...
???

Yeah, I hear ya ... take a class ...

Regards,
JS

Antenna for shortwave reception
 

RHF wrote:

...
- Any good college debate class will quickly teach
- someone that point--the first day of class!
-
- Regards,
- JS

JS,

Sounds like you are a pretty good 'debater' yourself.

maybe you studied under mwb ? ;-} ~ RHF
.

My credentials only allow me to do CS ... :-( But hey, stranger things
have happened! :-)

Regards,
JS

Antenna for shortwave reception
 

In article ,
John Smith wrote:

RHF wrote:

...
- Any good college debate class will quickly teach
- someone that point--the first day of class!
-
- Regards,
- JS

JS,

Sounds like you are a pretty good 'debater' yourself.

maybe you studied under mwb ? ;-} ~ RHF
.

My credentials only allow me to do CS ... :-( But hey, stranger things
have happened! :-)

Another Usenet debater. Just what we needed.

--
Telamon
Ventura, California

Antenna for shortwave reception
 

On Dec 25 2008, 10:48*pm, BCBlazysusan wrote:
On Dec 25, 2:02*pm, bpnjensen wrote:





On Dec 23, 3:25*pm, Telamon

wrote:
In article ,
*John Smith wrote:

Don't bring the amateur antenna group into these discussions. That group
has a bunch of key clowns in it.

Yeah, they actually build antennas for all frequencies, something you
obviously do not ... ROFLOL

Most amateurs do not.
Most amateurs buy them.
Most amateurs would not know how to build them.

No amateurs operate on all frequencies idiot.

Idiot, he said connect an antenna to the whip.

No he didn't idiot. He even mentioned that the radio comes with the
ANT-60 antenna, which plugs into the antenna jack not clip onto the whip
antenna. The clip is for holding the far end of the windup part of the
antenna to something so the antenna can be held off the ground, idiot..

Ummm - to try to remain on-topic, yes the 909 has an external antenna
jack, although in my recollection it does not come with a suitable
antenna, nor does that jack connect you in a meaningful way to the MW
band if you connect it according to the instructions. *It must be done
using a 3-conductor phono plug with one pair of conductors shorted
(IIRC). *I do not have my reference for this handy, but the schematic
is available last time I knew on various web sites.

For that matter, I don't think the "clip to the whip" gives a
meaningful MW boost either - just SW/HF.

Bruce Jensen- Hide quoted text -

- Show quoted text -

I really need to break out my DX398/909
I was reading your post Bruce and I do seem to remember what you are
saying. All I know is that I didn't get/didn't like what I was
receiving using the internal antenna jack. Actually I was somewhat
dissapointed when I got the radio. But there are many things one can
do for that piece to make it a real dynamo on SW/BCB/FM. I sent mine
to Chris Justice at RadioLabs and the mods he did really really
changed my opinion of the receiver itself and I kept it. He installed
another type of antenna connection to the back of the radio. I never
really put up anything antenna wise to truly check that specific mod.- Hide quoted text -

- Show quoted text -

I like the RadioLabs mods too - big improvement and makes the radio
lots more fun.

Bruce