Why Antenna Tuners Aren't Necessarily Useful for Shortwave Listening - Question Shortwave Listening (SWL) Antenna Tuners - Do You Have An Opinion ?
RHF
QUESTION - Shortwave Listening (SWL) Antenna Tuners
- - - Do You Have An Opinion ? - - -
Why Antenna Tuners Aren't Necessarily Useful for Shortwave Listening
http://www.nyx.net/~dgrunber/tuner.ssi
- - - by - - - Daniel A. Grunberg
Here is "Dan Grunberg's Home Page"
http://www.nyx.net/~dgrunber/
Welcome - Here are some of my documents that may interest you.
TOPIC - SHORTWAVE RADIO :
* Advice to Shortwave Newbies
(Useful sources of information and useful links)
* Minimal Antennas and Grounds
(Why they may be all you need)
* So You're Certain You Need an Outdoor Antenna
(With a link to a reasonable design)
* Why Antenna Tuners Aren't Necessarily Useful
for Shortwave Listening
(This article could save you some money)
* A Rambling Review of the Lowe HF-150
(A nice receiver)
* Nifty 48-Inch (122-cm) Whip Antenna
with a PL-259 Connector
* The Sony 7600G and Its Synchronous Detector
(Why sync detectors are worth having)
* Analog vs. Digital Receivers (an introduction)
* Preventing Wire Antennas from Breaking in the Wind
and that's Today's On-Topic Post - iane ~ RHF
.
.
. .
.
Bob Miller
wrote:
>For One and All,
>
>QUESTION - Shortwave Listening (SWL) Antenna Tuners
>- - - Do You Have An Opinion ? - - -
>
>Why Antenna Tuners Aren't Necessarily Useful for Shortwave Listening
>http://www.nyx.net/~dgrunber/tuner.ssi
>- - - by - - - Daniel A. Grunberg
The same argument could be used to say, "Why 9-to-1 Baluns Aren't
Necessarily Useful for Shortwave Listening."
Bob
k5qwg
John S.
RHF wrote:
> For One and All,
>
> QUESTION - Shortwave Listening (SWL) Antenna Tuners
> - - - Do You Have An Opinion ? - - -
>
> Why Antenna Tuners Aren't Necessarily Useful for Shortwave Listening
> http://www.nyx.net/~dgrunber/tuner.ssi
> - - - by - - - Daniel A. Grunberg
>
> Here is "Dan Grunberg's Home Page"
> http://www.nyx.net/~dgrunber/
>
> Welcome - Here are some of my documents that may interest you.
>
> TOPIC - SHORTWAVE RADIO :
>
> * Advice to Shortwave Newbies
> (Useful sources of information and useful links)
>
> * Minimal Antennas and Grounds
> (Why they may be all you need)
>
> * So You're Certain You Need an Outdoor Antenna
> (With a link to a reasonable design)
>
> * Why Antenna Tuners Aren't Necessarily Useful
> for Shortwave Listening
> (This article could save you some money)
>
I have found that antenna tuners provide tactile entertainment for the
bored SWL, but little more. They are a couple more knobs to twist.
David
wrote:
If one is a true RF professional the idea of putting a Hi Z generator
into a Low Z load is too much. The 9:1 autotransormer also puts every
part of the antenna at DC ground, thus protecting the radio's input.
Plus, it's a very elegant way to connect the wire to the shielded
cable.
Bob Miller
Still, you have that wonderfully sensitive receiver, and your balun
hasn't changed the signal to noise ratio; it's only made everthing
louder. Same argument he's using against antenna tuners :-)
bob
k5qwg
David
wrote:
>Still, you have that wonderfully sensitive receiver, and your balun
>hasn't changed the signal to noise ratio; it's only made everthing
>louder. Same argument he's using against antenna tuners :-)
>
>bob
>k5qwg
>
It does help signal:noise. It keeps the antenna away from the house.
Slow Code
news:1141804211....@i39g2000cwa.googlegroups.com:
Nice on-topic post. A tuner isn't really necessary for impedance matching,
but it can act as a pre-selector if your receiver has a poor front end in it.
Which can help improve things in some situations.
SC
Bob Miller
And the rest of the noise? Powerlines, atmospheric noise, heterodynes,
etcetera? And do you really think coax keeps manmade noise out?
bob
k5qwg
David
wrote:
>On Wed, 08 Mar 2006 18:40:32 GMT, David <ric...@knac.com> wrote:
>
>>On Wed, 08 Mar 2006 17:05:33 GMT, Bob Miller <NOS...@neosoft.com>
>>wrote:
>>
>>>Still, you have that wonderfully sensitive receiver, and your balun
>>>hasn't changed the signal to noise ratio; it's only made everthing
>>>louder. Same argument he's using against antenna tuners :-)
>>>
>>>bob
>>>k5qwg
>>>
>>It does help signal:noise. It keeps the antenna away from the house.
>
>And the rest of the noise? Powerlines, atmospheric noise, heterodynes,
>etcetera? And do you really think coax keeps manmade noise out?
>
>bob
>k5qwg
It keeps the noise I make out of my radio.
Telamon
Slow Code <e...@il.here> wrote:
People like to argue about tuners and pre-selectors so I would like to
expand on this a little.
A pre-selector is basically a band pass filter. Main use is to attenuate
out of band signals that may, depending on how good your radios blocking
is, be very helpful in reducing false images from showing up and making
reception of in band signals messy and confusing. Some units are
adjustable to the point that even some in band signals can be
attenuated. This fine-tuning is good from the standpoint that radio has
a narrower range of signals to block and this should result in improved
signal to noise as any time you limit the bandwidth of a spectrum the
noise floor drops. Noise is broadband energy and any time you limit the
received bandwidth you reduce the noise power. Obviously the better the
receiver is designed the less there is to be gained by using a
pre-selector.
An antenna tuner is a circuit used to resonate an antenna at the
frequency of operation. The effect on reception appears similar but
occurs for a different reason. Because the action of the tuner causes
the antenna to be optimized for the frequency of operation, the range of
frequencies above and below it are relatively attenuated due to not
being picked up as efficiently so you get a similar result but for a
different reason.
Why is the distinction important? Because the pre-selector can go
anywhere in the transmission line (coax) from antenna to radio and is
most often conveniently located near the radio. The tuner needs to be a
part of the antenna and so is located there where its output is at the
coax transmission line to the radio.
The pre-selector is an in line band-pass filter that can go anywhere
along the transmission line. The antenna tuner is located at and is
actually a part of the antenna.
What's is that? You say hams use antenna tuners in the shack for
transmitting purposes. This is not a good practice but if they are using
an antenna that is close to resonance and are just trying to protect the
transmitter from dealing with the additional reflected power then its OK
but in using it they are not improving how well their antenna functions.
The tuner in the shack does not improve or change how well their antenna
radiates.
Another thing people keep endless repeating is that nether antenna
tuners or pre-selectors help and just make signals louder (they mean
stronger), which of course with the AGC operation of the radio means the
result of using either is the S meter reads higher. This is only true
for medium to strong signals. For a weak signal, the signal to noise
should at least have a small improvement, determined by how weak the
signal was to begin with, receiver design, local noise, and current
propagation. If the signal is very weak, the tuner and pre-selector
could result in it being readable. Here the antenna tuner has the best
possibility of making a signal that is below the receiver noise floor
strong enough to be heard (detected) on the radio.
In summery, in my opinion, a pre-selector would be a good bet to improve
portable reception when connected to an external antenna especially the
worse case single conversion units. Following that in usefulness would
be an antenna tuner. People chasing DX with tabletop units might want to
try antenna tuners where less useful for them would be pre-selector use.
--
Telamon
Ventura, California
Bob Miller
<telamon_s...@pacbell.net.is.invalid> wrote:
>
>In summery, in my opinion, a pre-selector would be a good bet to improve
>portable reception when connected to an external antenna especially the
>worse case single conversion units. Following that in usefulness would
>be an antenna tuner. People chasing DX with tabletop units might want to
>try antenna tuners where less useful for them would be pre-selector use.
And, I would pre-sume the "pre-amp" is different from the
pre-selector?
bob
k5qwg
David
wrote:
>On Wed, 08 Mar 2006 20:59:22 GMT, Telamon
A receiver pre-amp can get the signal (and noise) above the AGC
threshold so at least the volume will be constant. A pre-amp between
the antenna and the transmission line can keep the cable from
attenuating the signal too much. However, at HF frequencies, line
losses are for the most part inconsequential.
Telamon
Bob Miller <NOS...@neosoft.com> wrote:
Good assumption.
I'm not big on pre-amps because they add their own noise to the existing
signal to noise but they can help. For an amp the be a help it must be
low noise and the best location would be at the antenna. Amps are best
used where you have a long run of coax. Other feature enhancements of
the amp design can come into play to make them more valuable.
--
Telamon
Ventura, California
nm...@wt.net
>into a Low Z load is too much.
LOL...A true RF pro probably wouldn't use a random wire
in the first place.. :/
MK
nm...@wt.net
Not from the 9:1 transformation though. Only due to the grounding ,
and decoupling of the feedline. The 9:1 balun is not required to
fulfill
that job. Bob is right. It's fairly rare to actually improve the s/n
ratio
just from the transformer on a wire of any decent length.. You already
have more signal than you need without a transformer, unless the
radio is half dead, or the antenna wire is very short. The improvement
in local noise is due to decoupling of the feedline, not the match.
And yes, a tuner can tighten up the front ends of many radios.
Not needed for actual signal level, but they can reduce out of band
crud. IE: my IC-706 receives some MW-BC crud on 160m. But if
I put my tuner inline, it kills it. I have different tuners, but my
main
tuner is a mfj 989c I picked up for nothing. But normally, I use no
tuner. I use it for the wattmeter only 98% of the time. All my
antennas
are resonant on the bands they are designed for, and don't need a
tuner on any other bands I might tune. I've got buckoo signal..I could
lose 3/4 of what I have and still probably not reduce my s/n ratio on
most
all HF bands.
MK
David
I disagree.
Telamon
nm...@wt.net wrote:
They work well in a low local noise location.
A random or long wire could be a good reference antenna against a new
design.
--
Telamon
Ventura, California
Slow Code
news:telamon_spamshield-4...@newsclstr02.news.prodigy.com:
As you said in your first sentence, people will argue about it. I agree
with what you say.
My point is that when you use a tuner with a receiver, it's acting as a
bandpass, which is the cause of the improvement if the receiver needs
front end help, Unwanted signals affecting the AGC are reduced. Impedance
matching with a tuner on HF I don't think you hear a difference. Maybe
we're meaning the same thing but saying it different ways.
SC
Slow Code
news:telamon_spamshield-F...@newsclstr02.news.prodigy.com:
And a wire is also quick & Cheap, when you need something in a hurry.
nm...@wt.net
As will nearly anything.
>A random or long wire could be a good reference antenna against a new
>design.
To me, a random wire would be a poor reference antenna. To me, there
are basically two reference antennas. The horizontal dipole, which
would
be the reference for horizontal antennas, and the 1/4 monopole, which
would be a reference to compare against vertical antennas.
For elevated verticals, I use the 1/4 wave ground plane as the
reference
antenna.
A random wire is much too random. The antennas I use as benchmarks
all have well known and repeatable performance. All my horizontal wire
antennas are compared to the 1/2 wave dipole. BTW, not many win either,
unless they are gain antennas. As far as efficiency on a certain band,
it's
hard to beat a coax fed dipole. And thusly, it's my usual "benchmark"
antenna.
MK
mi...@sushi.com
Telamon
nm...@wt.net wrote:
> >They work well in a low local noise location.
>
> As will nearly anything.
Well that's the point of using a common mode antenna.
You are not making logical sense. The random wire non-resonant common
mode antenna is a good reference antenna precisely because it has little
theoretical gain and it will work anywhere. You compare it against a
dipole and the dipole should show gain over it as should any other
antenna type made to be resonant at some frequency. Stop thinking like
an amateur, this is a SW listening news group. A random wire is the
basic antenna here. If you want technical antenna theory then yeah a
dipole is a basic reference radiator most transmit antennas.
--
Telamon
Ventura, California
RHF
THE PROFESSIONAL {AMATEUR} VIEW POINT
- - - HAMMING IT UP ! - - -
The 1/2 Wave Length Dipole and the 1/4 Wave Length Vertical are both
good Technical {Reference} Antennas for the "Specific Frequency"
related to their Measured Wave Lengths. For Amateur {Ham} Radio use
where you are Operating in a Certain Amateur Band and on a Single
Selected Frequency; they are excellent Receive and Transmit Antennas.
SHORWAVE LISTENING (SWL) - HEY IT'S JUST A HOBBY
[ KEEPING IT SIMPLE AND PRACTICAL ] {KISAP}
The Random Wire Antenna that is generally good on All Frequencies
across the Shortwave Bands from 1.8 MHz to 30 MHz is the most commonly
used Antenna for Shortwave Listening (SWL) and thus is the Practical
{Reference} Antenna for the Shortwave Listener (SWL). It is simply
A-Common-Point-of-Reference for All Shortwave Listeners (SWLs) to
'compare' the relative perfromance of their respective Shortwave
Listening (SWL) Antennas. The Random Wire Antenna, while not very
good on any Specific Frequency is simply so-so-good across All
Shortwave Frequencies. To some extent the qualities that make an
'un-tuned' Random Wire a poor Amateur Antenna; are the same qualities
that make it a very good Shortwave Listening (SWL) Antenna. The
modern solid-state General Coverage 1.8 MHz to 30 MHz Shortwave
Receiver has enough Gain and sufficient Dynamic Range to make full use
of the Signal Levels that can be producted by a Random Wire Antenna
that is 35 Feet to 105 Feet long. For most Shortwave Listeners (SWLs)
what more do they need other than Lower Noise and Better Signal Quality
relative to Noise. {Improved Signal-to-Noise S/N Ratio}.
The-Bottom-Line : The Random Wire Antenna is :
+ Simple
+ Practical
+ More Than "Good Enough"
For the vast majority of the Shortwave Listener's
(SWLs) Shortwave Radio Listening Needs [.]
THE NEXT STEP - LOW NOISE INVERTED "L" {RANDOM WIRE} ANTENNA
Starting with the Random Wire Antenna and incorporating a few
improvements can result in an Shortwave Listening (SWL) Antenna that
has for it's size and placement a better Signal-to-Noise S/N Ratio then
a plain Random Wire {so-called Longwire} Antenna
THREE-TO-READ BY JOHN DOTY :
* The Inverted "L" Antenna 'Shape' lends itself to the Design
Concepts of a "Low Noise Antenna" that has been popularized
by John Doty; consisting of: Antenna Element; Matching Transformer;
Grounding Point; Coax Cable Feed-in-Line; and Radio/Receiver.
DOTY=> http://www.anarc.org/naswa/badx/antennas/low-noise_antenna.html
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/2
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/374
- Two Reasons to use a Balun (Matching Transformer)
with a Receive Only Antenna.
DOTY=> http://www.anarc.org/naswa/badx/antennas/SWL_longwire.html
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/150
- Magnetic Longwire Balun (MLB) - Build Your Own "DIY"
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/177
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/466
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/467
- Balun Reading List ( Long )
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/337
- The "Grounding-Point" = Ground Rods and Ground Wires ETC.
DOTY=> http://www.anarc.org/naswa/badx/antennas/grounding.html
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/425
http://www.hard-core-dx.com/nordicdx/antenna/ground/
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/470
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/539
LIST OF MORE TO READ - Low-Noise Invered "L" Antenna
* How does the "Doty" Inverted-L Antenna do . . .
http://groups.google.com/group/rec.radio.shortwave/msg/3fff7ab457d5966c
http://groups.google.com/group/rec.radio.shortwave/msg/97aaa91efcba72d6
http://groups.google.com/group/rec.radio.shortwave/msg/dd1f2641323eed34
http://groups.google.com/group/rec.radio.shortwave/msg/02a2a935f52a5d65
* Question is 'it' a Longwire {Random Wire} Antenna -or- Inverted "L"
Antenna ?
http://groups.google.com/group/rec.radio.shortwave/msg/85364956151adbba
http://groups.google.com/group/rec.radio.shortwave/msg/76f4e4ded6f94686
http://groups.google.com/group/rec.radio.shortwave/msg/dea571f3bebdca61
* Questions on Inverted "L" Antenna
http://groups.google.com/group/rec.radio.shortwave/msg/e0b3ddbed819958d
http://groups.google.com/group/rec.radio.shortwave/msg/f6f7b5506cc942e2
http://groups.google.com/group/rec.radio.shortwave/msg/c890a154db93a89a
http://groups.google.com/group/rec.radio.shortwave/msg/c14b09ea224f4434
* Basic Antenna Question - - - Noise Reducing Antennas
The SWL Version of the Inverted "L" Antenna
works well as an Omni-Directional Antenna.
http://groups.google.com/group/rec.radio.shortwave/msg/776c390272c6c91f
http://groups.google.com/group/rec.radio.shortwave/msg/43463ad863e5b075
http://groups.google.com/group/rec.radio.shortwave/msg/3effeaab835e3bb6
* WHY - The simple Random Wire Antenna is better than
the Dipole Antenna for the Shortwave Listener (SWL)
http://groups.google.com/group/rec.radio.shortwave/msg/bb023dcbd76abc37
http://groups.google.com/group/rec.radio.shortwave/msg/83ecfc2f91fe5c7e
http://groups.google.com/group/rec.radio.shortwave/msg/e1d43c05075de087
http://groups.google.com/group/rec.radio.shortwave/msg/4ced7dc5f3aadadc
http://groups.google.com/group/rec.radio.shortwave/msg/6238331627ba89a1
* Random Wire Antenna Question . . .
http://groups.google.com/group/rec.radio.shortwave/msg/952aaad971aa2c2f
http://groups.google.com/group/rec.radio.shortwave/msg/0a56237ce6553389
http://groups.google.com/group/rec.radio.shortwave/msg/3b68df4a9df55dae
http://groups.google.com/group/rec.radio.shortwave/msg/103fe02cad4e5650
* Low Noise Shortwave Listener's (SWL) Antenna - by Design
http://groups.google.com/group/rec.radio.shortwave/msg/17ab857189fec531
http://groups.google.com/group/rec.radio.shortwave/msg/1426baf640c5d346
http://groups.google.com/group/rec.radio.shortwave/msg/95be7387aae66292
http://groups.google.com/group/rec.radio.shortwave/msg/c3b0ba01c418c6c9
http://groups.google.com/group/rec.radio.shortwave/msg/ce57f23580332f73
http://groups.google.com/group/rec.radio.shortwave/msg/4e07cc179fcc3dbd
http://groups.google.com/group/rec.radio.shortwave/msg/a9e1f930c8d189db
* Consider Buying or Building a better Shortwave Listener's (SWL)
Antenna.
http://groups.google.com/group/rec.radio.shortwave/msg/b02ff595de9fea91
http://groups.google.com/group/rec.radio.shortwave/msg/a1f41e85486b0ed9
http://groups.google.com/group/rec.radio.shortwave/msg/4311c0ac4f084b87
http://groups.google.com/group/rec.radio.shortwave/msg/3effeaab835e3bb6
hope this helps - iane ~ RHF
.
.
Tous Sont Bienvenus ! - - - Groupe par Radio
d'auditeur d'onde courte pour des Antennes de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Alle Sind Willkommen ! - - - Shortwave Radiozuhörer
Gruppe für SWL Antennen
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Tutti Sono Benvenuti ! - - - Gruppo Radiofonico
dell'ascoltatore di onda corta per le Antenne di SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Todos São Bem-vindos ! - - - Grupo de Rádio
do ouvinte do Shortwave para Antenas de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Все Радушны ! - - - Группа оператора
на приеме коротковолнового диапазона
Radio для Aнтенн SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
¡Todos Son Agradables! - - - Grupo de Radio del oyente
de la onda corta para las Antenas de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
= = = = = Translation = = = = =
All are Welcome - - - To Join the Shortwave Listeners
(SWL) Antenna Group on YAHOO !
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
nm...@wt.net
>mode antenna is a good reference antenna precisely because it has little
>theoretical gain and it will work anywhere.
So the same can be said for a 1/2 wave dipole. The gain of a length
of wire will not vary much depending on how it's fed. Only the length
really matters. Of course, different methods of feeding vary as far as
system efficiency. In the case of 1/2 wave or smaller wires, the
efficiency of the feed system is about the only thing that matters
much among the various versions of such.
> You compare it against a
>dipole and the dipole should show gain over it as should any other
>antenna type made to be resonant at some frequency.
How you fiqure? If the random wire were longer than the 1/2 WL dipole,
it could actually have more gain in a certain direction. The reason a
dipole is the common benchmark for horizontal wires is because it's a
well known measured quanity. Exactly what you want as a "benchmark",
or reference antenna. Look at most any antenna ad's for yagi's. If you
can find one that is measured against a random wire, I'll send you $20.
Most all will be measured against a 1/2 wave dipole at the same height,
or instead be listed as dbi, which is a theoretical value. The only
difference
between dbd and dbi is about 2.1 db. You are just shifting your
reference.
> Stop thinking like
>an amateur, this is a SW listening news group.
What does that have to do with anything? I place no distinction between
an
antenna used for transmit, and one receive. They both obey the same
laws.
I use the same types of antennas for both jobs. The better an antenna
is
at transmitting , in general ditto for receive. The properties of an
antenna
between transmit, and receive are reciprical. IE: if an antenna has
gain in a
certain direction, this applies equally transmit, or receive. I will
always
use the best antenna for the job I can put up. And that is rarely ever
a
random wire. Random wires are too micky mouse for my blood.
But you can consider that a personal problem. :/
> A random wire is the
>basic antenna here.
Sure, it may be for some, but I'm sure not all are content
to stay with one antenna their whole life.
I'm just as much as SWL as you are, and my "basic" antenna is
a 1/2 wave dipole. I've been SWLing since 1964, when I got my
first radio at the age of 8. A good bit longer than I've been a ham.
I didn't get into ham radio until the 8th grade. Didn't get legal until
77.
When did you start SWLing? If it's longer than 42 years, I'll give
you a free cookie.
>If you want technical antenna theory then yeah a
>dipole is a basic reference radiator most transmit antennas.
Whether it's for transmit or not is not really relevant.
What other kind of antenna theory is there?
Do they also have "sears" antenna theory, "geico" antenna
theory, "dimbulb" antenna theory, etc?
I thought there was just one version...
Heck, the other guy was the one that brought up what "pro's"
would use or do. Pro's don't measure antennas against
random wires. And I doubt most would use one if they could
use something better. I don't use random wires, and I'm not
even a pro. :/ Are you suggesting I would be a better SWLer
if I changed to random wires? That'll be the day... :/ LOL...
MK
--
nm...@wt.net
of the thread. If you don't like my opinions, thats
too bad. An antenna is an antenna is an antenna.
Do you think when I switch from a SWL to a ham band,
I need to switch antenna types? LOL...You guys kill me..
MK
David
We're not worthy...
Bob Miller
wrote:
A random length dipole will work as well as any random length "wire."
With or without an antenna tuner. And be easier to feed.
Bob
k5qwg
>For One and All,
>
>THE PROFESSIONAL {AMATEUR} VIEW POINT
>- - - HAMMING IT UP ! - - -
Amateurs are not professionals...
>excerpted...
>
>excerpted...
>
David
wrote:
>On 11 Mar 2006 23:12:08 -0800, "RHF" <rhf-new...@pacbell.net>
>wrote:
>
>A random length dipole will work as well as any random length "wire."
>With or without an antenna tuner. And be easier to feed.
>
>Bob
>k5qwg
>
''Random length dipole'' makes little sense.
How...@hisisp.com
aka 'Doublet' where you have two equal lengths of wire that are not
cut to any specific frequency, rather they are cut to fit the maximum
dimension you have available. Doublets are typically fed with
twinlead and a tuner is used.
How...@hisisp.com
Well how can your receiver work with an antenna made for transmit 8-}
cuh...@webtv.net
yard.If I think an antenna tuner might be usefull for me,I will drive on
over to MFG Enterprises and let them folks suggest something for me.Noo
to much a drive for me to make,we are in the same State.
cuhulin,the Mississippi
David
Unless you have a real radio I wouldn't bother. Is your Royal 1000
working?
David
cuh...@webtv.net
cuhulin
Bob Miller
An alternative would be a non-random length dipole resonant on several
swl bands without the need for an antenna tuner. See...
http://www.universal-radio.com/catalog/sw_ant/3377.html
I used to have the sloper version of the above. Worked great.
bob
k5qwg
David
wrote:
>On Sun, 12 Mar 2006 07:42:11 -0800, How...@hisisp.com wrote:
>
>>On Sun, 12 Mar 2006 15:33:26 GMT, David <ric...@knac.com> wrote:
>>
>>>On Sun, 12 Mar 2006 14:26:15 GMT, Bob Miller <NOS...@neosoft.com>
>>>wrote:
>>>
>>>>On 11 Mar 2006 23:12:08 -0800, "RHF" <rhf-new...@pacbell.net>
>>>>wrote:
>>>>
>>>>A random length dipole will work as well as any random length "wire."
>>>>With or without an antenna tuner. And be easier to feed.
>>>>
>>>>Bob
>>>>k5qwg
>>>>
>>>''Random length dipole'' makes little sense.
>>
>>aka 'Doublet' where you have two equal lengths of wire that are not
>>cut to any specific frequency, rather they are cut to fit the maximum
>>dimension you have available. Doublets are typically fed with
>>twinlead and a tuner is used.
>
>An alternative would be a non-random length dipole resonant on several
>swl bands without the need for an antenna tuner. See...
>
>http://www.universal-radio.com/catalog/sw_ant/3377.html
>
>I used to have the sloper version of the above. Worked great.
>
>bob
>k5qwg
David
cuh...@webtv.net
Allyey wetahhhh,,,, shock me Alliwetahhhhh,,,,,,,,
cuhulin
(Polish music jazz)
Bob Miller
The MFJ 16010 random wire tuner would do well with your sloper; runs
about $49.99...
Say howdy to Martin...
bob
k5qwg
Telamon
nm...@wt.net wrote:
I did not ask to get bagged on by an amateur. Learn to post without
being offensive.
--
Telamon
Ventura, California
Telamon
How...@hisisp.com wrote:
Basically (theoretically) an antenna made for transmit is just as
suitable for receive. This is called reciprocity.
This concept falls apart two ways in practicality:
1. The transmit situation has to handle power the receive situation does
not so for transmit the antenna elements need to be "beefier."
2. A less than full size antenna made resonant may work very well for
transmit but for receive not as well. Less than full size for receive
lowers the antenna efficiency.
--
Telamon
Ventura, California
Telamon
How...@hisisp.com wrote:
The concept here is that on receive size matters so a dipole antenna
made for the lowest frequency band you want to receive will be a
multiple wavelength antenna on higher frequencies. The only rub here is
that it will not work well on even harmonics so be sure to pick a size
that ends up as an odd electrical harmonic length on the higher bands.
--
Telamon
Ventura, California
How...@hisisp.com
Telamon,
Thanks for the friendly answer - however, I was aware of what you
mention. My earlier response was just a case of me being flippant in
my response to MK.
Howard
Telamon
nm...@wt.net wrote:
> >You are not making logical sense. The random wire non-resonant common
> >mode antenna is a good reference antenna precisely because it has little
> >theoretical gain and it will work anywhere.
>
> So the same can be said for a 1/2 wave dipole.
Fine then everything is relative.
> The gain of a length of wire will not vary much depending on how it's
> fed. Only the length really matters. Of course, different methods of
> feeding vary as far as system efficiency. In the case of 1/2 wave or
> smaller wires, the efficiency of the feed system is about the only
> thing that matters much among the various versions of such.
Well that's just the way it is for electrically short wires. What you
missing here is the wire is half the antenna and the energy it picks up
is common mode and not just a function resonate length.
> >You compare it against a dipole and the dipole should show gain over
> >it as should any other antenna type made to be resonant at some
> >frequency.
>
> How you fiqure? If the random wire were longer than the 1/2 WL
> dipole, it could actually have more gain in a certain direction. The
> reason a dipole is the common benchmark for horizontal wires is
> because it's a well known measured quanity. Exactly what you want as
> a "benchmark", or reference antenna. Look at most any antenna ad's
> for yagi's. If you can find one that is measured against a random
> wire, I'll send you $20. Most all will be measured against a 1/2 wave
> dipole at the same height,
>
> or instead be listed as dbi, which is a theoretical value. The only
> difference between dbd and dbi is about 2.1 db. You are just shifting
> your reference.
Yes a dipole is a classic reference antenna. This is not an amateur news
group.
> > Stop thinking like an amateur, this is a SW listening news group.
>
> What does that have to do with anything? I place no distinction
> between an antenna used for transmit, and one receive. They both obey
> the same laws. I use the same types of antennas for both jobs. The
> better an antenna is at transmitting , in general ditto for receive.
> The properties of an antenna between transmit, and receive are
> reciprical. IE: if an antenna has gain in a certain direction, this
> applies equally transmit, or receive. I will always use the best
> antenna for the job I can put up. And that is rarely ever a random
> wire. Random wires are too micky mouse for my blood. But you can
> consider that a personal problem. :/
>
> > A random wire is the basic antenna here.
>
> Sure, it may be for some, but I'm sure not all are content to stay
> with one antenna their whole life. I'm just as much as SWL as you
> are, and my "basic" antenna is a 1/2 wave dipole. I've been SWLing
> since 1964, when I got my first radio at the age of 8. A good bit
> longer than I've been a ham. I didn't get into ham radio until the
> 8th grade. Didn't get legal until 77. When did you start SWLing? If
> it's longer than 42 years, I'll give you a free cookie.
Please consider your audience before posting or keep on Trolling you
jerk.
> >If you want technical antenna theory then yeah a
> >dipole is a basic reference radiator most transmit antennas.
>
> Whether it's for transmit or not is not really relevant. What other
> kind of antenna theory is there? Do they also have "sears" antenna
> theory, "geico" antenna theory, "dimbulb" antenna theory, etc? I
> thought there was just one version... Heck, the other guy was the one
> that brought up what "pro's" would use or do. Pro's don't measure
> antennas against random wires. And I doubt most would use one if
> they could use something better. I don't use random wires, and I'm
> not even a pro. :/ Are you suggesting I would be a better SWLer if
> I changed to random wires? That'll be the day... :/ LOL...
Well based on my reading of amateur news groups there is ham antenna
theory and then the theory the world actually operates on.
As you say LOL...
Laugh all you want. I'll just keep pointing out that the news group is
for short wave listening not ham radio. That the simplest antenna is a
Marconi type single wire antenna and if a listener wants to make an
antenna better than that he would expect a payoff in the way of stronger
received signals so one too weak before could now be heard, better
signal to noise or maybe directionality for various reasons. Please
consider your audience before posting or just keep on Trolling.
Your a good example of why I no longer read the amateur news groups and
am not a ham operator. Why would I want to go out of my way to talk to
someone like you.
--
Telamon
Ventura, California
Telamon
How...@hisisp.com wrote:
When I post whether a new thread or in this case a reply I try to be
informative as this is not like email where a reply would go directly to
you.
Hopefully other people reading the thread get a better idea of
what will work better for them. Besides there is no way for me to know
what you know or what experience you have except for what you explicitly
write and I have to guess the rest.
A level of knowledge a person has is an interesting thing in itself.
Some people are aware of the reciprocity concept and leave it at that
but you can always look at things in a deeper way that modify or even
appear to reverse a rule.
--
Telamon
Ventura, California
Bob Miller
<telamon_s...@pacbell.net.is.invalid> wrote:
>In article <abg8121qrppovnn2o...@4ax.com>,
> How...@hisisp.com wrote:
>
>> On 12 Mar 2006 01:08:39 -0800, nm...@wt.net wrote:
>>
>> >Hey, you asked for opinions in your first post
>> >of the thread. If you don't like my opinions, thats
>> >too bad. An antenna is an antenna is an antenna.
>> >Do you think when I switch from a SWL to a ham band,
>> >I need to switch antenna types? LOL...You guys kill me..
>> >MK
>>
>> Well how can your receiver work with an antenna made for transmit 8-}
>
>Basically (theoretically) an antenna made for transmit is just as
>suitable for receive. This is called reciprocity.
>
>This concept falls apart two ways in practicality:
>1. The transmit situation has to handle power the receive situation does
>not so for transmit the antenna elements need to be "beefier."
Most transmitting antennas use wire about the same size as what's
found in receiving-only antennas, 14 or 16 guage, maybe 12 guage for
full legal power.
>2. A less than full size antenna made resonant may work very well for
>transmit but for receive not as well. Less than full size for receive
>lowers the antenna efficiency.
I seriously doubt you could hear the difference between a full size
antenna at frequency, and one slightly shorter for space
considerations.
bob
k5qwg
Telamon
Bob Miller <NOS...@neosoft.com> wrote:
> On Sun, 12 Mar 2006 22:28:19 GMT, Telamon
> <telamon_s...@pacbell.net.is.invalid> wrote:
>
> >In article <abg8121qrppovnn2o...@4ax.com>,
> > How...@hisisp.com wrote:
> >
> >> On 12 Mar 2006 01:08:39 -0800, nm...@wt.net wrote:
> >>
> >> >Hey, you asked for opinions in your first post
> >> >of the thread. If you don't like my opinions, thats
> >> >too bad. An antenna is an antenna is an antenna.
> >> >Do you think when I switch from a SWL to a ham band,
> >> >I need to switch antenna types? LOL...You guys kill me..
> >> >MK
> >>
> >> Well how can your receiver work with an antenna made for transmit 8-}
> >
> >Basically (theoretically) an antenna made for transmit is just as
> >suitable for receive. This is called reciprocity.
> >
> >This concept falls apart two ways in practicality:
> >1. The transmit situation has to handle power the receive situation does
> >not so for transmit the antenna elements need to be "beefier."
>
> Most transmitting antennas use wire about the same size as what's
> found in receiving-only antennas, 14 or 16 guage, maybe 12 guage for
> full legal power.
Ever calculate antenna resistance at HF for those gauges? What is the
expected loss for some band you worked on?
What is legal power for hams on HF? 1500 watts? And is that continuous
power or PEP?
> >2. A less than full size antenna made resonant may work very well for
> >transmit but for receive not as well. Less than full size for receive
> >lowers the antenna efficiency.
>
> I seriously doubt you could hear the difference between a full size
> antenna at frequency, and one slightly shorter for space
> considerations.
On receive the antenna efficiency is related to is size by means of
radiation resistance. Antenna efficiency is directly dependent on the
combination of radiation and antenna element resistance (DC+AC).
This affects the received signal power just like it does for transmit
but like I said on transmit you can use materials with higher dielectric
constants and reactive components to launch an EM wave efficiently.
However, on receive you can't affect the environment around the antenna
in the same fashion as the antenna itself therefor what I stated stands
unless you can refute it.
The key here in the non-reciprocity of antenna performance is the fact
that "you can't affect the environment around the antenna in the same
fashion as the antenna itself." The environment around the antenna has
an impedance value not affected by the antenna but antenna size directly
correlates to radiation resistance.
Think about it. If you were right then everyone would be using a whip
antenna. Why bother to build full size antennas?
--
Telamon
Ventura, California
RHF
So you use the same Amateur Radio Antenna
for the 160m and 80m Bands as you do for the
6m and 2m Bands.
http://en.wikipedia.org/wiki/Amateur_radio
160-Meter Amateur Band = 1.815 to 1.89 MHz
80-Meter Amateur Band = 3.5 to 3.8 MHz
6-Meter Amateur Band = 50-54 MHz
2-Meter Amateur Band = 144-148 MHz
MK # 1 - " An antenna is an antenna is an antenna. "
But A Piece of Wire - Now That's Electrical ! :o)
MK #2 - "Do you think when I switch from a SWL
to a ham band, I need to switch antenna types? "
MK - As an Amateur radio Opperator - If you were using
a 20-Meter Dipole Antenna to Talk Coast-to-Coast
http://www.chem.hawaii.edu/uham/20.html
-or- a SkyWire {NVIS} Loop Antenna for your local-area "Net" Work
http://groups.google.com/group/rec.radio.shortwave/msg/c8c8553f4137bb58
http://groups.google.com/group/rec.radio.shortwave/msg/291803362ae6952f
http://groups.google.com/group/rec.radio.shortwave/msg/c173213a11be0b83
http://groups.google.com/group/rec.radio.shortwave/msg/8401f389f911c57d
- - - Then just may be you would want to switch over to an 45
to 100 Foot Inverted "L" Shortwave Listener's (SWLs) Antenna
to be able to Hear-Around-the-World from all directions with ease.
* 45 Foot Shortwave Listener (SWL) Inverted "L" Antenna
15 Foot Vertical Up-Leg with a 30 Foot Horizontal Out-Arm
* 100 Foot Shortwave Listener (SWL) Inverted "L" Antenna
25-33 Foot Vertical Up-Leg with a 67-75 Foot Horizontal Out-Arm
http://groups.google.com/group/rec.radio.shortwave/msg/b092a8ef6391bce6
MORE "LN-ILA" READING => http://tinyurl.com/j9erj
Note - LN-ILA = Low Noise Inverted "L" Antenna - a la John Doty
just - keeping it simple and practical {KISAP}
cause - iane ~ RHF
.
.
All are WELCOME and "Invited to Join" the
Shortwave Listener (SWL) Antenna eGroup on YAHOO !
<http://groups.yahoo.com/group/Shortwave-SWL-Antenna/>
SWL ANTENNAS GROUP => http://tinyurl.com/an6tw
.
Some Say: On A Clear Day You Can See Forever.
I Believe : On A Clear Night You Can Hear Forever
. . . and Beyond , , , The BEYOND ! ! !
With a Shortwave Listening Antenna of your own making.
"If You Build It {SWL Antenna} You Will Hear Them !"
<http://groups.yahoo.com/group/Shortwave-SWL-Antenna/>
SHORTWAVE ANTENNA FORUM => http://tinyurl.com/an6tw
RHF
Most {The Majority} of Amateur {Ham} Radio Operators
take "Their" Amateur Radio License as Personal Badge of
Honor and it could be said that "They" view themselves as
Hobbyist with a 'professional' Level of Technical Knowledge.
- - - FWIW - IMHO - They Are Right [.]
BM [K5QWG] - "And be easier to feed."
Ah ! - Spoken like a True Amateur {Ham} Radio Operator.
Speaking from the prospective of a Shortwave Listener (SWL)
"The Wire(s)" connecting an Antenna (Wire Antenna Element)
to the Radio {Receiver} are the Feed-in-Line : That which 'brings'
the Radio Signal from the Antenna to the Radio.
- - - Where as - The Amateur {Ham} Radio Operator 'thinks' of
"The Wire(s)" connecting an Antenna to the Transmitter as the
Antenna FEED : That which 'sends' the Radio Signal from the
Transmitter to the Antenna.
The Amateur {Ham} Radio Operator -vice- The Shortwave Listener (SWL)
Two View Points : The Expertise of a Two-Way Communicator
-vice- The Enjoyment of a Simple Radio Listener {Hobbyist}
The-Bottom-Line - Shortwave {Radio} Listening (SWL) :
it does not have to be technical to be enjoyable - iane ~ RHF
FWIW - Just Keeping It Simple And Practical { KISAP :-}
RHF
The Dipole or Doublet works best for the Shortwave Listeners
(SWLs) general all around all-directions and all-frequency needs :
WHEN - One of the two equal Wire Antenna Elements {Arms}
is Bent-in-Half and Down Vertically to the ground at one end only.
* The Dipole or Doublet is fed from the Center either with
Twin-Lead / Ladder-Line or a 1:1 of 4:1 Balun and Coax Cable.
- - - My choice for a Shortwave Listener (SWL) would be the
4:1 Balun and Coax Cable Feed-in-Line to the Radio / Receiver.
* The Straight-Arm of the Dipole or Doublet is Rigged like
a normal Dipole or Doublet Antenna.
* The Bent-Arm of the Dipole or Doublet is Rigged like an
Inverted "L" that is fed from the Top-Far-End.
* The Bent-Arm is Measured and and Half the Length
is Horizontal and the other Half of the Length is Vertical.
to within One Foot of the ground surface.
Note - For a Half-Wave (1/2 WL) Dipole this means that the
Rigging Height of the Doublet's Horizontal Arms is about a
1/8 WL above ground level.
* * The Horizontal Arm Sections are 1:2
* * The Vertical Up-Leg Section to the Horizontal Arm Sections are 1:3.
Conclusion - The Bent-Quarter-Doublet Antenna with a
4:1 Balun and Coax Cable Feed-in-Line can be a very
effective Shortwave Listening (SWL) Antenna :
WHERE - Three Mounting Points are available for
Rigging the Doublet Antenna.
IN WHAT EVER - Space is Available for the Doublet Antenna
{Random Wire Dipole type Antenna} to be Rigged.
doublet-or-nothing - iane ~ RHF
RHF
Louder Than I Normally Do :o) - iane ~ RHF
{ Theme : Shortwave Listening is the Topic
Keep It Simple And Practical - KISAP }
nm...@wt.net
>Fine then everything is relative.
If you say so... A benchmark should be a known quantity,
if it's going to be of any real use to more than one person.
> The gain of a length of wire will not vary much depending on how it's
> fed. Only the length really matters. Of course, different methods of
> feeding vary as far as system efficiency. In the case of 1/2 wave or
> smaller wires, the efficiency of the feed system is about the only
> thing that matters much among the various versions of such.
>Well that's just the way it is for electrically short wires. What you
>missing here is the wire is half the antenna and the energy it picks up
>is common mode and not just a function resonate length.
Sure, it's only half the antenna if you feed it against ground.
But I don't run those types of antennas.
> or instead be listed as dbi, which is a theoretical value. The only
> difference between dbd and dbi is about 2.1 db. You are just shifting
> your reference.
>Yes a dipole is a classic reference antenna. This is not an amateur news
group.
Again, I never said it was. A dipole is still a classic reference
antenna
even here on this group. I don't change theory when I change groups.
> > A random wire is the basic antenna here.
> Sure, it may be for some, but I'm sure not all are content to stay
> with one antenna their whole life. I'm just as much as SWL as you
> are, and my "basic" antenna is a 1/2 wave dipole. I've been SWLing
> since 1964, when I got my first radio at the age of 8. A good bit
> longer than I've been a ham. I didn't get into ham radio until the
> 8th grade. Didn't get legal until 77. When did you start SWLing? If
> it's longer than 42 years, I'll give you a free cookie.
>Please consider your audience before posting or keep on Trolling you
>jerk.
I'm very damn well aware of what group I'm posting on. Troll? Jerk?
You piss and whine about my short post to RHF where I ask about
his wanting opinions, and you say that I'm offensive in that post,
which
is most certainly not the truth. But you sit on this thread and call me
a troll and a jerk, just because what I say chaps your ass in some
way. You need to take some of your own advice.
I'll give you something to really whine about, you twinkled toed
peckergrip.. You are one prime time asshole, you know that don't
you? And your buddy RHF ain't too far behind it seems.
>Well based on my reading of amateur news groups there is ham antenna
>theory and then the theory the world actually operates on.
You must not read too well then. Either that or the "other" groups
you refer to must not be too up on antenna theory. Again, there is only
one set of antenna theory. There are not ham versions, SWL versions,
etc..
>As you say LOL...
Damn right. You and RHF crack me up. You two think you own
this frigging group don't you. This group is not just "SWLing for
newbies". As far as I know, even more advanced SWLers can hang
out here. Or do you have some kind of problem with that? I
suspect you probably do, being as you think you own this group.
>Laugh all you want. I'll just keep pointing out that the news group is
>for short wave listening not ham radio.
And I'll keep pointing out that I've never made any mention of amateur
radio. Only you, or RHF. Anyone that can read, can see that is true.
Why would I talk about ham radio to a bunch of non hams? You need to
get a grip.
>That the simplest antenna is a
>Marconi type single wire antenna and if a listener wants to make an
>antenna better than that he would expect a payoff in the way of stronger
>received signals so one too weak before could now be heard, better
>signal to noise or maybe directionality for various reasons. Please
>consider your audience before posting or just keep on Trolling.
I'm well aware of what a Marconi is. And I'm well aware of why I
prefer not to use them for any purpose. Have you read any of my
posts where I hold a gun to the head of all these SWL's, and
force them to use a dipole, or any other antenna? I could
give a flying flip what you , RHF, or anyone else around here
use. But I will surely tell all what *I* prefer to use. If you don't
like it, don't let the door slap you in the ass on the way out.
I'm not going anywhere, and if youAnd RHF keep spouting your whiny
horsecrap in my direction, I'm going to be here every frigging day
of the week. Just to bug the crap out of you. I'll live for it. Trust
me.
>Your a good example of why I no longer read the amateur news groups and
>am not a ham operator. Why would I want to go out of my way to talk to
>someone like you.
Who cares. I'm sure I probably wouldn't want to talk to a tightass
dipshit
like you anyway. I've said it once. I'll say it again, you are one
prime
time asshole. I've tried to cut you slack and be fairly pleasant to
you over the last few months, if not ignore you altogether.
But I can see that is not going to work.
So...Fuck you. Put me in your kill file, you twinkle toed wanker.
Sheeeshh...What a whiny ass prick you are.
MK
nm...@wt.net
> Hey, you asked for opinions in your first post
> of the thread. If you don't like my opinions, thats
> too bad. An antenna is an antenna is an antenna.
> Do you think when I switch from a SWL to a ham band,
> I need to switch antenna types? LOL...You guys kill me..
>I did not ask to get bagged on by an amateur. Learn to post without
>being offensive.
Fuck you.
MK
nm...@wt.net
a 20-Meter Dipole Antenna to Talk Coast-to-Coast
-or- a SkyWire {NVIS} Loop Antenna for your local-area "Net" Work
- - - Then just may be you would want to switch over to an 45
to 100 Foot Inverted "L" Shortwave Listener's (SWLs) Antenna
to be able to Hear-Around-the-World from all directions with ease.
* 45 Foot Shortwave Listener (SWL) Inverted "L" Antenna
15 Foot Vertical Up-Leg with a 30 Foot Horizontal Out-Arm
* 100 Foot Shortwave Listener (SWL) Inverted "L" Antenna
25-33 Foot Vertical Up-Leg with a 67-75 Foot Horizontal Out-Arm
http://groups.google.com/group/rec.radio.shortwave/msg/b092a8ef6391bce6
Why in the hell would I switch to a junky inv L for 20m, when I have a
4 element yagi? Get a grip... You goofballs are getting fairly silly.
MK
RHF
For someone who is just interested in Listening to "Their" Radio it
is simply another thing to do that "They" don't necessarily what to do
. . .
[ Playing with an Antenna Tuner -or- Pre-Selector ]
They = Their = Them = The 'casual' Shortwave Radio Listener (SWL)
For "Them" a 9:1 Matching Transformer, Remote Ground Rod and
Coax Cable Feed-in-Line are the Install-It-and-Forget-It Answer
to most of "Their" Signal-to-Noise Radio receiving problems that
is related to the Shortwave Listener's (SWLs) Radio and Antenna
and Greater Enjoyment of "Their" Radio Listening pastime.
FWIW - For Me Shortwave Radio Program Listening
is a Relaxing Hobby that I do for 'personal' Enjoyment.
Life Can Be Complicated :-( ---and---
Listening to your Radios should be Enjoyable :o)
everyone simple enjoy your radios and antennas ~ RHF
RHF
Now the Stage # 2 - Bad Attitude and Bad Language Assault.
mk - wow ! - you are a real amateur operator ;-) ~ RHF
[ MK - I Am Glad We Had This Conversation :<]
nm...@wt.net
>Now the Stage # 2 - Bad Attitude and Bad Language Assault.
Thats right. I have a hard time tolerating assholes that think
they own the newsgroup, and think they should be able to
determine the content of it's posters. Telewhine started the
scrap telling me I'm a troll, and a jerk, just because he
doesn't like some of my theories. I don't take crap off anyone.
Actually, I think he's got a purty mouth. :(
>mk - wow ! - you are a real amateur operator ;-) ~ RHF
>[ MK - I Am Glad We Had This Conversation :<]
You wouldn't know a real amateur if it bit you in the ass.
The real problem here, is telewhine, and maybe you also,
have some kind of problem with hams. I guess one must
have bent him over and drove him home at some point in the
past.
I consider this a personal problem, and none of my concern.
I rarely talk about ham radio on this group, and you should
know it, being you seem to live here about 24 hours a day.
MK
David
<telamon_s...@pacbell.net.is.invalid> wrote:
>Think about it. If you were right then everyone would be using a whip
>antenna. Why bother to build full size antennas?
Angle of radiation.
Bob Miller
<telamon_s...@pacbell.net.is.invalid> wrote:
Well, I could have built my 80 meter dipole out of copper pipe, but
the neighbors might have objected -- I used 18 guage stranded, which
is fine for my 100 watts, and would probably handle legal power, too.
For my 20 meter inverted L, I used #26 stranded. It's hooked to a
mightly 3.5 watt qrp rig.
>
>What is legal power for hams on HF? 1500 watts?
1500, and I believe it's continuous, but you can check the FCC site if
you wish.
> And is that continuous
>power or PEP?
>
>> >2. A less than full size antenna made resonant may work very well for
>> >transmit but for receive not as well. Less than full size for receive
>> >lowers the antenna efficiency.
>>
>> I seriously doubt you could hear the difference between a full size
>> antenna at frequency, and one slightly shorter for space
>> considerations.
>
>On receive the antenna efficiency is related to is size by means of
>radiation resistance. Antenna efficiency is directly dependent on the
>combination of radiation and antenna element resistance (DC+AC).
>
>This affects the received signal power just like it does for transmit
>but like I said on transmit you can use materials with higher dielectric
>constants and reactive components to launch an EM wave efficiently.
>However, on receive you can't affect the environment around the antenna
>in the same fashion as the antenna itself therefor what I stated stands
>unless you can refute it.
>
>The key here in the non-reciprocity of antenna performance is the fact
>that "you can't affect the environment around the antenna in the same
>fashion as the antenna itself." The environment around the antenna has
>an impedance value not affected by the antenna but antenna size directly
>correlates to radiation resistance.
>
>Think about it. If you were right then everyone would be using a whip
>antenna. Why bother to build full size antennas?
Well, they're more broad-banded, for one thing.
Once again, less-than-half-wave antennas, properly tweaked, are as
loud to my ears as half-wave antennas. I know I'm right because I'm
talking about what I hear.
As far as whip antennas go, actully, a lot of hams do pretty good on
75 meters with highly tweaked 6- or 8-foot whips on their cars.
bob
k5qwg
RHF
Why Don't 'you' Try Answering the Questions Asked ?
- - - vice - - -
Going-Off and advoiding the facts and issues at hand ?
MK - So 'you' are the type of Amateur Operator
who uses one Antenna on All-Bands ?
MK - Your 20-Meter Band 4-Element Yagi might be
Great on the Amateur 20 Meter Band and be 'ok' on
the 22 and 19 Meter Shortwave Bands - But honestly
would 'you' use it on the 60-49-41-31 Meter Shortwave
Bands ? ? ?
For the Shortwave Listener an Inverted "L" Antenna that
was 25 Feet High by 50 Feet Long would be a better
General All-Band SWL Listening Antenna then your Yagi.
Vertical-Up-Leg for 31-Meters = 1/4 WL @ 24.5 Feet
Horizontal-Out-Arm for 60-Meters = 1/4 WL @ 47.7 Feet
Total Length of the Wire Antenna Element 72.2 Feet
= = = One Antenna : Built-It & Rig-It = Enjoy-It :o)
[ An 'average' size SWL Antenna that can "Fit" InTo
the Urban Backyard. ]
For the Shortwave Listener wanting something a little
Bigger then an Inverted "L" Antenna that was 32 Feet
High by 71 Feet Long would be a little better General
All-Band SWL Listening Antenna - If they had the Space
and the Ability-to-Rig the Antenna Wire that High .
Vertical-Up-Leg for 41-Meters = 1/4 WL @ 31.8 Feet
Horizontal-Out-Arm for 90-Meters = 1/4 WL @ 70.9 Feet
Total Length of the Wire Antenna Element 102.7 Feet
= = = One Antenna : Built-It & Rig-It = Enjoy-It :o)
[ A 'larger' size SWL Antenna that can "Fit" InTo
the Urban Backyard. ]
Alas, many Shortwave Listeners can only have an
Inverted "L" Antenna that is a little smaller and 15
Feet High by 30 Feet Long would be the best that
they could do for a General All-Band SWL Listening
Antenna - Since that have very limited space and
can only Rig oh-so-high.
Vertical-Up-Leg for 19-Meters = 1/4 WL @ 15.1 Feet
Horizontal-Out-Arm for 41-Meters = 1/4 WL @ 31.8 Feet
Total Length of the Wire Antenna Element 46.9 Feet
= = = One Antenna : Built-It & Rig-It = Enjoy-It :o)
[ A 'small' size SWL Antenna that can "Fit" InTo
the smaller Urban Backyard. ]
Note - The Par EF-SWL Antenna lends itself to this
'small' Inverted "L" Antenna Rigging and it is only 45
Feet Long and includes the Wire Antenna Element
and Matching Transformer - Just add Ground Rod
plus Coax Cable and you are ready to Rig-It and
Enjoy Listing to your Radios.
http://www.universal-radio.com/catalog/sw_ant/2205.html
* Par Electronics EF-SWL
http://groups.google.com/group/rec.radio.shortwave/msg/9db0c1f933b5e495
http://groups.google.com/group/rec.radio.shortwave/msg/ee85739bddf54cc3
http://groups.google.com/group/rec.radio.shortwave/msg/672c697b586250c4
http://groups.google.com/group/rec.radio.shortwave/msg/d7802953c2ef0642
http://groups.google.com/group/rec.radio.shortwave/msg/b368cb105b4a370b
* ABOUT USING - The Par Electronics End-Fed
Shortwave Listener {EF-SWL} Antenna
http://groups.google.com/group/rec.radio.shortwave/msg/a1f41e85486b0ed9
http://groups.google.com/group/rec.radio.shortwave/msg/4311c0ac4f084b87
http://groups.google.com/group/rec.radio.shortwave/msg/38d00e8131ee9876
http://groups.google.com/group/rec.radio.shortwave/msg/45a68a64cf6d8a00
http://groups.google.com/group/rec.radio.shortwave/msg/3c157d690257b8ad
* Consider Buying or Building a better Shortwave Listener's (SWL)
Antenna.
Lets Think : Out-of-the-Box {Ready-Made} Shortwave Listener (SWL)
Antennas
WHY - The simple Random Wire Antenna is better than the Dipole Antenna
for the Shortwave Listener (SWL)
http://groups.google.com/group/rec.radio.shortwave/msg/b02ff595de9fea91
http://groups.google.com/group/rec.radio.shortwave/msg/a91e9554b3d7d7ee
http://groups.google.com/group/rec.radio.shortwave/msg/d9905736ffa71e6e
http://groups.google.com/group/rec.radio.shortwave/msg/bb023dcbd76abc37
http://groups.google.com/group/rec.radio.shortwave/msg/c890a154db93a89a
MK - Remember for the Shortwave Listener the SWL Antenna
is just-a-means to being able to Listen to "Their" Radios and
Enjoying the Listening Experience.
mk - enjoy being a ham :o) -and- i will continue to enjoy . . .
just being a shortwave listener (swl) - iane ~ RHF
.
All are WELCOME and "Invited to Join" the
Shortwave Listener (SWL) Antenna eGroup on YAHOO !
<http://groups.yahoo.com/group/Shortwave-SWL-Antenna/>
SWL ANTENNAS GROUP => http://tinyurl.com/an6tw
.
Some Say: On A Clear Day You Can See Forever.
I Believe : On A Clear Night You Can Hear Forever
. . . and Beyond , , , The BEYOND ! ! !
With a Shortwave Listening Antenna of your own making.
"If You Build It {SWL Antenna} You Will Hear Them !"
<http://groups.yahoo.com/group/Shortwave-SWL-Antenna/>
SWL ANTENNAS GROUP => http://tinyurl.com/an6tw
.
.
. .
.
RHF
of the Rec.Radio.Shortwave NewsGroup :o)
MK - I will now tell Telamon to be 'nice-to-you' ;-}
Telamon - Be Nice To MK ! - please :<]
Oops - My Super-Powers as the NewsGroup Owner
are not working - - - I feel so weak and helpless ;-(
mk - i will try again tomorrow, Tomorrow. TOMORROW ! ~ RHF
[ Butt Alass - Tomorrow Never Comes ! ]
RHF
Shortwave Antenna was the so-called Longwire Antenna.
CLASSIC - SHORTWAVE LONGWIRE ANTENNA {KIT}
A simple 50-100 Foot long piece of Bare Copper Wire
plus a 30-50 Foot long piece of Insualted Copper Wire
add a 5-15 Foot long piece of Solid Copper Ground Wire
and a Cold Water Pipe Ground Strap. Add-in a few
Insulators. With the 'complete' One Page of Instructions
including a Diagram and Parts List.
Now That Is A "CLASSIC" When It Comes To Shortwave
Listening (SWL) Antennas and Shortwave Radios for the
last 75-100 Years.
Hey MK - It Is Such A "Classic" that RadioShack
still offers one for sale today :
* Outdoor Antenna Kit for Shortwave Radios
RadioShack Catalog # 278-758
http://www.radioshack.com/product/index.jsp?productId=2104088
mk - there are classics -and- Then There Are Classics ~ RHF
[ A Shortwave Goodbye :<]
David
wrote:
You forgot the fire extinguisher.