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

Dave wrote:

...
I don't recognize "politician" as being a monolithic culture. There are
decent ones and there are many more ****-heads, but that holds true for
society in general.

I don't believe that.

Simply because, in the last 30+ years, I have NEVER seen ANYTHING get
any better--or, at least those things which are in the realm of things
influenced by politics, legislation produced by politicians, or for that
matter, ANYTHING done by politicians!

They are there because of their desire for either money, power, or both.
They support a shadow government solely for what benefits they, their
family and friends get from the individuals in this elite group.
Although, the above would be impossible to prove at this date; I
believe a through awareness and study of the direction "things"
constantly seem to be going in leaves one with no other possible
conclusion(s) ...

Regards,
JS

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

JB wrote:

...
Actually there is no reason TO have a resonant length antenna if you can
tune it electrically. After all, you may want to tune around some. I can
tell you it is a pain to have to go out and physically make adjustments for
any frequency excursion. There are many nonresonant length antennas that
outperform the resonant length. The 5/8 wave vertical comes to mind. A
long-wire provides a larger capture area. Then there are phased arrays that
reinforce. Look up the HAARP project and see how they made a very large
array and were able to electrically steer the pattern. Cool!

The more you know, the cheaper it gets, and the more you giggle when it
works. The only problem is you get hooked and want to do so much more.


Well, examine a mechanical tuning fork. They are cut to an exact
physical length for resonance, the are very sharp tuning. Now, it would
be possible to "lengthen" such a tuning fork with some coil of material,
or portion of a turn of material. There is a reason for this; as,
although it could be done, it would not be as efficient as one cut to
the exact length; plus, you would induce a high probability of increased
harmonics as a freq(s) which the fork was not created to induce ...
there are exact equivalents in the electrical world of RF ...

As you point out, physical length resonance is NOT a requirement ... it
is simply "best" ...

Regards,
JS

Antenna for shortwave reception
 

On Dec 27, 6:14*pm, John Smith wrote:
Dave wrote:
...
You are not "pumping" any more "power" into a non-resonant antenna.
Unless you are using a tuner you are heating up your finals.

First, your use of "resonant" is just plain confusing ...

All my multiband antennas, which I have ever use in life, are physically
resonate on but one freq (or band.) *On the others, they are only
electrically resonate (and, lossy loading components are used to effect
this.)

A matchbox can always improve the reception on a poorly designed
antenna, a mismatched antenna, a non-physically resonate antenna, etc.

John Smith,

OK then what is a 'matchbox' in :
* a poorly designed transmitting antenna,
* a mismatched transmitting antenna,
* a non-physically resonate transmitting antenna,

Consider the 'matchbox' to be one element
in the RF Energy Radiating System :
Feed-Line + 'matchbox' + Antenna Element

i want to know - iane ~ RHF

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

John Smith wrote:
Dave wrote:

...
I don't recognize "politician" as being a monolithic culture. There
are decent ones and there are many more ****-heads, but that holds
true for society in general.

I don't believe that.

Simply because, in the last 30+ years, I have NEVER seen ANYTHING get
any better--or, at least those things which are in the realm of things
influenced by politics, legislation produced by politicians, or for that
matter, ANYTHING done by politicians!

They are there because of their desire for either money, power, or both.
They support a shadow government solely for what benefits they, their
family and friends get from the individuals in this elite group.
Although, the above would be impossible to prove at this date; I
believe a through awareness and study of the direction "things"
constantly seem to be going in leaves one with no other possible
conclusion(s) ...

Regards,
JS

You pretend to be powerless to fight this...

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

Dave wrote:
John Smith wrote:
RHF wrote:

...
js - but alas i remain a simple shortwave listener
who simply enjoys listening to the radio; cause
practically speaking; that is what i do
- - - respectfully ~ RHF
.

Quit peeing on my leg ...

Brother, I enjoy having a good time, a good drink and the company of a
good woman as well as anyone; And, furthermore, I am here because I
enjoy a good antenna as well as anyone else.

I am here because some know much more than me, can explain it in a
manner which I can absorb (Cecil is but one example), and I expect
there is much more for us ALL to learn, indeed ...

I ain't here to lecture you ... I ain't here to be a ham ... I ain't
here to play the game of "one-up-man-ship"; I am here to catch what I
missed "the-first-time-around"--end-of-story.

But now, a good argument, a good debate, a good "theory-session" ...
count me in!

Sit back, and pick on the next guy in line ... ;-)

Regards,
JS

A random wire (e.g. inverted L) transmits nicely if you use a tuner at
the feed point.

A resonate 1/4 wave dipole transmits "nicely" and uses no lossy tuner
.... a resonate 1/4 wave vertical monopole, with drooping ground plane,
transmits "nicely", requires no lossy tuner, and is damn near a perfect
match to 50 ohm coax ...

A 1/2 wave version of either of the above produces a superior pattern
and can be matched with either a T-match or gamma-match ... indeed, a
very minimal counterpoise is all which is necessary--and, if things are
"perfect", not even that is needed, or simply a choke on they outside of
the coax a ~1/4 wave away from feed point. A 5/8 is non-resonate
physical length, and even demonstrates a superior pattern (at least on
paper and with antenna prediction software ... )

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 ...

Regards,
JS

Antenna for shortwave reception
 

RHF wrote:

...
"N",

Don't know too many 'Hams' would would take 50 Feet
of common Speaker Wire and tie-a-knot at 30 Feet and
then split the two Wires in the remaining 20 Feet and
use the thing as a "Stealth" Dipole Antenna with their
Transmitter -but- a Shortwave Radio Listener (SWL)
can do that and have a very practical SWL Antenna
to use with many 'portable' AM&FM Shortwave Radios.

50-Ft. 24-Gauge Clear 2-Conductor Speaker Wire
RadioShack Catalog # 278-1301
http://www.radioshack.com/product/in...ductId=2102499

"n" - practically speaking {in practice} there is a
difference between between hams and swls ~ RHF
.
.


I have taken ordinary lamp zip cord, split the two leads apart to for a
1/4 wave dipole and fed the end of the remaining length of zip cord with
a balun to the rig (some zip cord is ~68-72 ohm balanced line, the
mismatch is more than acceptable for field/emergency use.)

Never, say never ... some ham will do it!

Regards,
JS

Antenna for shortwave reception
 

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

Dave wrote:

...
You pretend to be powerless to fight this...

My single voice IS powerless against the sheer magnitude of the
onslaught I would launch it against. However, the power of my voice
combined with thousands, tens-of-thousands, hundreds-of-thousands ... of
other voices eventually can and does make changes; and, is as it should be.

Regards,
JS

Antenna for shortwave reception
 

RHF wrote:


OK then what is a 'matchbox' in :
* a poorly designed transmitting antenna,
* a mismatched transmitting antenna,
* a non-physically resonate transmitting antenna,

Consider the 'matchbox' to be one element
in the RF Energy Radiating System :
Feed-Line + 'matchbox' + Antenna Element

i want to know - iane ~ RHF
.


It would be far more "in the realm of correct" to consider what a
matchbox DOES, rather than what it IS--as it is simply some combination
of inductive and capacitive components which ALWAYS will induce some
form of loss into any system it is inserted into.

However:
*a matchbox will allow you to use a poorly designed/constructed
antenna--it will NOT improve the antenna.

*a matchbox will allow you to "match" differing impedances to achieve
proper power transfer to the antenna--again, it will NOT improve the
efficiency of that antenna, and the power will be "simply lost" (as heat.)

*a matchbox CAN allow you to alter the electrical length of an
antenna--physical and electrical lengths are two different animals.

And, this is all-in-a-nut shell; as you realize, a proper education in
this field is NOT a trivial thing.

That said, I frequently carry a cheap portable with me on trips and
launch a longwire into a tree, etc., find acceptable signals and enjoy
listening ... or else, just grab the SW stations audio from the net ...
being an old-timer, the first is more enjoyable, for me.

Regards,
JS

Antenna for shortwave reception
 

Sum Ting Wong wrote:
On Sat, 27 Dec 2008 12:27:09 -0800, John Smith
wrote:

The same antenna which transmits the MOST EFFICIENT signal possible,
will also receive the signal the MOST EFFICIENTLY

If that were true then the BIG boys on 160m would have no need for
tall vertical transmitting antennas and traveling wave (Beverage)
receive antennas. They could just use one or the other for both
transmitting and receiving, but they don't. That's because one is
better for transmitting and one is better for receiving.

S.T.W.

That is simply ridiculous, as I stated, in any properly designed
antenna, with the proper pattern to achieve the points in question, and
able to handle xmitter power, and is the MOST efficient for the purpose
at hand will be EQUALLY efficient in both transmitting and receiving ...

On 160m, I have ALWAYS used the same antenna to transmit as to receive ...

What I stated is ABSOLUTELY TRUE ... and, there is but one truth
possible here. And, certainly, in the situation you stated above, a
discrepancy (imbalance) has been, absolutely, induced, as one antenna
will out preform the other, have a different pattern, etc.

However, a beverage would NOT be my first choice for a transmitting
antenna! And, certainly, there is no comparison over the directionality
difference (i.e., patterns) between these two antennas!

Regards,
JS