On Sun, 12 Mar 2006 22:28:19 GMT, Telamon
wrote:

In article ,
wrote:

On 12 Mar 2006 01:08:39 -0800, 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."
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,
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

In article .com,
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

In article ,
wrote:

On Sun, 12 Mar 2006 22:28:19 GMT, Telamon
wrote:

In article ,
wrote:

On 12 Mar 2006 01:08:39 -0800, 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." 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, 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.

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

On Sun, 12 Mar 2006 22:28:19 GMT, Telamon
wrote:

In article ,
wrote:

On 12 Mar 2006 01:08:39 -0800, 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

In article ,
Bob Miller wrote:

On Sun, 12 Mar 2006 22:28:19 GMT, Telamon
wrote:

In article ,
wrote:

On 12 Mar 2006 01:08:39 -0800, 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

MK,

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 ! )

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.r...c8553f4137bb58
http://groups.google.com/group/rec.r...1803362ae6952f

http://groups.google.com/group/rec.r...73213a11be0b83
http://groups.google.com/group/rec.r...01f389f911c57d

- - - 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.r...92a8ef6391bce6

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

BM [K5QWG] - "Amateurs are not professionals..."

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 :-}

On Mon, 13 Mar 2006 04:10:24 GMT, Telamon
wrote:

In article ,
Bob Miller wrote:

On Sun, 12 Mar 2006 22:28:19 GMT, Telamon
wrote:

In article ,
wrote:

On 12 Mar 2006 01:08:39 -0800, 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?

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

MK,

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 )
[ 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 )
[ 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 )
[ 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.r...b0c1f933b5e495
http://groups.google.com/group/rec.r...85739bddf54cc3
http://groups.google.com/group/rec.r...2c697b586250c4
http://groups.google.com/group/rec.r...802953c2ef0642

http://groups.google.com/group/rec.r...68cb105b4a370b


* ABOUT USING - The Par Electronics End-Fed
Shortwave Listener {EF-SWL} Antenna
http://groups.google.com/group/rec.r...f41e85486b0ed9
http://groups.google.com/group/rec.r...11c0ac4f084b87
http://groups.google.com/group/rec.r...d00e8131ee9876

http://groups.google.com/group/rec.r...a68a64cf6d8a00

http://groups.google.com/group/rec.r...157d690257b8ad

* 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.r...2ff595de9fea91

http://groups.google.com/group/rec.r...1e9554b3d7d7ee
http://groups.google.com/group/rec.r...905736ffa71e6e

http://groups.google.com/group/rec.r...023dcbd76abc37
http://groups.google.com/group/rec.r...90a154db93a89a

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 ) -and- i will continue to enjoy . . .
just being a shortwave listener (swl) - iane ~ RHF

On 14 Mar 2006 01:52:50 -0800, "RHF"
wrote:

MK - For the Shortwave Listener (SWL) the 'classic'
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/in...ductId=2104088


mk - there are classics -and- Then There Are Classics ~ RHF
[ A Shortwave Goodbye :]
.
You forgot the fire extinguisher.