Antenna for shortwave reception
 

On Dec 27, 10:05*am, wrote:
On Dec 26, 9:12 pm, RHF wrote:



Please don't cross post to rec.radio.amateur.antenna. Normally it would
be the right thing to do but that amateur group has a real collection of
idiots in it and this news group already has its share of that type.

But if you insist on cross posting there I can guarantee you there will
be more of what you don't like to see here.

--
Telamon
Ventura, California

PJ - Telamon Is Right :o)

No he's not. He's a bigger horses ass than nearly
anyone on rraa.. * :/
And that's a fact. Only "John Smith" might give him
a run for his money in that dept. * :/
But I'm not a whiner like Telamon, and try to tell
people what groups to use, or avoid.
They have horses asses of some kind on all the
groups. I just ignore *them*. Not the whole group.
It's like "John Smith". I think he's a horses ass,
but I don't try to tell him where to go, or others to
avoid him. I just lets the chips fall where they may.
Most people don't need me to help them decide
who is a horses ass, and who is not.
It becomes fairly obvious with the passage of time.
:/



i am a trolling idiot and i approve of his post ;-} ~ RHF
{sa-prez : trolling idiots-r-us}

I won't argue...

*.
IMHO the Rec.Radio.Amateur.Antenna people are
good people -but- They 'focus' on two disciplines :
Power Output Handling -and- Ability To Hear
[Cause They Both Transmit and Listen]

-while- The Shortwave Radio Listeners (SWL) is also
'focus' on two disciplines : Improved Signal plus Noise
Reduction -aka- Better Signal-to-Noise (S/N) Ratio
[Cause They "Only' Listen and Do Not Transmit]

This is purely cheap ground luncheon loaf... IE: bologna
Radio reception is radio reception. It does not matter
if one is a ham, or SWL, or whatever. The rules do not
change due to the type of service being received.
I almost never worry about power handling. Most of
my antennas will take way more power than I would
ever use. It's rarely even a consideration.
What is "ability to hear"? *It's basically the same thing
as S/N ratio. In this regard, there is no difference
what type of service is received, S/N ratio is equally
important.

Read these Posts here on Rec.Radio.Shortwave about
the Low Noise Shortwave Radio Antenna Concepts that
were 'popularized;
*.
Here are the Three Key Posts :
*.
# 1 - SWL Longwire -by- John Doty
* Actually, a fixed matching transformer can dramatically
reduce the wild swings in antenna efficiency that a coax
fed wire antenna exhibits.

But! that will rarely effect the S/N ratio on the shortwave
bands. Like Roy said, if you can disconnect the antenna,
and the background noise noticeably drops , you have
plenty of signal. Adding a better match will rarely
increase the S/N ratio on HF, because the desired signal
and the undesired noise increase at an equal level.
You have pumped up the S meter readings, but you
have not improved the actual S/N ratio.
When I use my large multi band dipoles for SW reception
on 49 meters, do you think I bother with a tuner?
Nope.. Total waste of time being I already have way
more signal than I would ever need even if looking into
a large mismatch.

*.
# 2 - Low Noise Antenna Connection -by- J
* The difference between a mediocre antenna system and
a great antenna system isn't the antenna itself: it's
the way you feed signals from the antenna to the receiver.
* The real trick with a shortwave receiving antenna system
is to keep your receiver from picking up noise from all
the electrical and electronic gadgets you and your
neighbors have.

I can't argue with this. But trust me, hams are no different
than SWL's when it comes to trying to reduce local noise
pickup. This is just common sense, and not a practice
only used by SWL's. * :/

*.
# 3 - Grounding Is Key To Good Reception

Now, this part here is just plain ole horse manure.
Grounding is not a "key" to good reception, unless you
are using an antenna that requires a ground connection
in order to complete the antenna.
Or the grounding is to further decouple the feed line
from the antenna. *But you don't require a ground
to decouple a feed line. It's just one method commonly
used with random length antennas fed with a coax
feed line.
None of my wire antennas require a ground connection
as they are complete antennas unto themselves.
Ground can actually be a source of noise in many
cases.

To sum, some make a mountain out of a molehill. :/
Richard Clarks simple solution of just adding more wire
to the whip on the radio is likely to work just as well
as anything proposed so far. If local noise is a
problem, then he might consider feeding an outside
wire with a decoupled feedline.
Anything further than that is likely S meter pumping
overkill.

"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

Antenna for shortwave reception
 

On Dec 27, 12:53*pm, 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.

Well, sure, but what does transmitting have to do with
anything? We are not talking about transmitting.
We are talking about receiving, "or at least I am", and
the rules do not change when you vary the frequency a
few mhz.
And there are more than one ways to skin a cat with a
given piece of wire. If I had a portable that normally used
a whip antenna for SW, I would be much more likely to
take that zip cord and split it totally apart to make a
single 100 ft wire. I would simply clip it onto the whip.
I bet my version would be the better performer of the
two, low bands for sure. But this has nothing to do
with what I'm listening to. If I'm listening on a ham rig,
and I'm not transmitting, I'm a SWL the same as anyone
else. :/
And most certainly so if I'm listening to a broadcast band
like 31m, or whatever. Do you think I play by different
rules than you if we are both listening to 31m at the same
time?
I hope not... :/
Sure, you can make a quite decent and usable SWL
antenna from nothing but a piece of wire, or zip cord.
But that is not a requirement to be a ®real SWL.
How would you like to try listening to 19m DX on my
tri-band yagi, which is still close enough to 20m, to
give pretty danged good performance and some F/B?

With that, why would I want to use a zip cord antenna?
It boggles the mind... :/
And I'm talking receive, not transmit. We'll pretend the
mike and keyer have been superglued to a tango-
uniform status.
But I guess being I'd rather use my full size yagi and
have a bit of F/B ratio, which improves S/N ratio, which
is the whole purpose of this topic, I'm not a ®real SWL..
Chortle.. :/
You two guys kill me... You really do.


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

Uh.. I know where to buy wire.. :/


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

No, there isn't. Not when it comes to receiving.
To propose otherwise is just ludicrous.
I listen to all the same bands you do at some
time or another. I was a rabid SWL when I was in
jr. high school. That was nearly 40 years ago.
I started DXing AM-BC when I was 8 years old
and got my first mighty six transister radio for my
birthday.
It's the main reason I'm a ham now. Just a natural
progression... In other words, I might have been
born yesterday, but not last night. :/

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.

Actually, this is a total misconception.

Download EZNEC or MMANA-GAL. Plugin the figures for a 1/4 wave physical
antenna "loaded" to 1/2 wave, examine the radiation pattern ...

Now, do the same for a full 1/2 wave physical length antenna and examine
the pattern ...

But then, I am sure you suspected, you can't take a 2 ft. antenna and
electrically resonate it to some other physical length, and have it
preform as the full physical length version ... if this were possible,
everyone would have little one inch antennas on their rigs ...

Regards,
JS

Antenna for shortwave reception
 

RHF wrote:

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


Simply a pipe dream ...

The same antenna which transmits the MOST EFFICIENT signal possible,
will also receive the signal the MOST EFFICIENTLY (given measuring
parameters remain the same for both modes, i.e., T/R) ... smaller gauge
components with far less power ratings can be used for receiving
antennas--that is the most important difference, and actually, the only
important one(s.)

However, I can see how some would come the the conclusion(s) you have.
In cheap receivers, you really don't know what ohm impedance the antenna
jack REALLY is. It may say 50 ohms and be 100, 200 ... 500 etc. Least,
that has been my experience ... when you get into professional gear,
costing thousands, they can take the time and aim for accuracy.

Regards,
JS

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

In article ,
Cecil Moore wrote:

JB wrote:
Actually there is no reason TO have a resonant length antenna if you can
tune it electrically.

Actually, tuning it "electrically" *is* tuning the antenna
*system* to resonance. When I vary my ladder-line length
to achieve system resonance, I am using my feedline as a
series tuning section. When one achieves a Z0-match with a
tuner or by other means, one is tuning the antenna system
to resonance which, in a near-lossless system, results in
near-conjugate match and near-maximum power transfer in
either direction (assuming the receiver input impedance
equals the Z0-match impedance).

This ever so helpful to the OP receiving antenna problem.

This was precipitated by the news group clown RHF who changed the
subject from "Antenna for shortwave reception" to the current "
Shortwave Radio Listener (SWL) Antennas -versus- Amateur Radio Antennas"

Good job Trolling jackass RHF.

--
Telamon
Ventura, California

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

Dave wrote:

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

Nicely is rather a broad term ...

And, if I am running 1KW+, or even multi-kilowatts, and the guy on the
other end is doing the same--we can communicate "nicely" on very poor
antennas ...

However, if I am running 5 watts, and the other guy is also, a properly
constructed antenna which has been designed around efficiency and most
desirable radiation pattern, along with having a correct impedance and
is matched EXACTLY to the equipment, and such is done without a lossy
"matchbox" or inefficient matching method--these would be of paramount
importance.

Physics, as much as math, is an EXACT science ... antennas are NOT in
realm of "art" (gray areas, open to interpretation, is a matter of
personal opinion, etc.), there is but one "best" antenna for any given
distance, terrain, pattern, etc.

Regards,
JS

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

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

Antenna for shortwave reception
 

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.

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

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.

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

John Smith wrote:
Dave wrote:

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

Nicely is rather a broad term ...

And, if I am running 1KW+, or even multi-kilowatts, and the guy on the
other end is doing the same--we can communicate "nicely" on very poor
antennas ...

However, if I am running 5 watts, and the other guy is also, a properly
constructed antenna which has been designed around efficiency and most
desirable radiation pattern, along with having a correct impedance and
is matched EXACTLY to the equipment, and such is done without a lossy
"matchbox" or inefficient matching method--these would be of paramount
importance.

Physics, as much as math, is an EXACT science ... antennas are NOT in
realm of "art" (gray areas, open to interpretation, is a matter of
personal opinion, etc.), there is but one "best" antenna for any given
distance, terrain, pattern, etc.

Regards,
JS