In article , "Wes Stewart"
wrote:

Antennas are reciprocal, if they wouldn't work well for transmitting,
they will work equally poorly for receiving.

The reciprocity principle is usually good physics (but watch out for
Faraday rotation). However, the engineering virtues of a good transmitting
and good receiving antenna are different. At HF and below, efficiency is
much less important for receiving than it is for transmitting. The reason
is that the natural noise level is high at these frequencies: at 10 MHz
it's 30 dB above thermal, while a good receiver's noise floor is 10 dB
above thermal. This leaves plenty of room for inefficiency without SNR
degradation. At lower frequencies the natural noise is higher. In practice
10 meters of untuned inverted L into a 500 ohm input suffices to reach the
natural noise floor from 100 kHz to 30 MHz with a good receiver.

Back in the days of the omega navigation system, we used tuned 2 meter
whips to receive signals from around the world in the 10 kHz band.

For the results of quantitative engineering calculations on this subject,
see:

http://anarc.org/naswa/badx/antennas/SWL_longwire.html

--
| John Doty "You can't confuse me, that's my job."
| Home:
| Work:

Wes Stewart ...

^ Antennas are reciprocal, if they wouldn't work well for
^ transmitting, they will work equally poorly for receiving.

I don't believe that. It's been my experience that an antenna used for
receiving will function satisfactorily over a much broader range of
conditions (environment, antenna length, etc.) than it will if used for
transmitting under those same conditions.

Frank

Believe what you will, the law of reciprocity will ignore your beliefs and
continue to function.

"Frank" wrote in message
news:01c3b0a2$989de120$0125250a@cqvdqntcxxawvjpo.. .
Wes Stewart ...

^ Antennas are reciprocal, if they wouldn't work well for
^ transmitting, they will work equally poorly for receiving.

I don't believe that. It's been my experience that an antenna used for
receiving will function satisfactorily over a much broader range of
conditions (environment, antenna length, etc.) than it will if used for
transmitting under those same conditions.

Frank

The difference between "satisfactory" in receiving and in transmitting antennas
is that in receiving, one just needs an antenna that provides signals strong
enough over the on-frequency noise for the receiver to process.

In transmitting, the output has to be a strong as possible to be above the
noise in the desired receiving location. A better antenna will increase the
transmission's erp toward the desired direction.

In summary:
For better reception, put your money into the receiver.
For better transmission, put your money into the antenna.

Bill, K5BY

On Sat, 22 Nov 2003 02:44:57 -0000, "Frank"
wrote:

|Wes Stewart ...
|
|^ Antennas are reciprocal, if they wouldn't work well for
|^ transmitting, they will work equally poorly for receiving.
|
|I don't believe that. It's been my experience that an antenna used for
|receiving will function satisfactorily over a much broader range of
|conditions (environment, antenna length, etc.) than it will if used for
|transmitting under those same conditions.

Mmm. In the case of atmospheric limited SNRs that is true. A trailing
wire under sea water receives just fine at ELF and doesn't work worth
a damn for transmitting. But those are special cases that can always
be manufactured. Beverage antennas are also not something to be used
for transmitting but you won't be disguising one as a chimney cap
either

In the general sense of h-f to microwave, I stand by my claim.

Wes

Sit on a cactus or something, Wes? You seem a little edgy.

Nobody is forced to buy into a neighborhood with covenants. One can do
exactly what you have done and buy some distance from your neighbors.
That's great if it works out for you.

However, my case is obviously different from yours. The home where I now
live is not the home I will own when I retire. I won't need nearly as many
bedrooms, etc., and it will be out on an acreage I own (that's currently a
little farther than I care to commute to my job). Living in a good
neighborhood with covenants makes sense for me right now, because I do want
to protect the hefty investment I've made in my home, specifically because I
do intend to sell it someday.

Just because covenants aren't ideal for your situation doesn't make them a
bad thing. As for your hair-splitting over "broadcasting," it was clear my
intent was "transmitting." -- just as it is clear your intent is to act like
an asshole.

-- Stinger


"Wes Stewart" wrote in message
...
On Fri, 21 Nov 2003 16:58:40 -0600, "Stinger"
wrote:

|Homeowners associations are a good thing! They are basically an
agreement
|that you and your neighbors will follow some clearly defined rules for
the
|specific purpose of maintining optimum property values for everyone. In
|other words, you won't have to worry about buying an expensive house and
|having your next-door neighbor decide to use his yard to store a dozen
|wrecked automobiles while he builds a hot-rod or runs a car-repair
business.
|Common sense should tell anyone that their rights end when they start to
|infringe on anyone else's, but sometimes you need it in writing. ;^)

I happen to subscribe to Fine Homebuilding Magazine and in one of the
latest issues there is some discussion about people who will not make
any changes to their house without considering resale value. They
could be eight feet tall and planning to remodel the kitchen, but will
they think of raising the height of the countertops to make it easier
on themselves? Nooooo. It will affect resale value. They might be
planning to die in the house but they worry that their heirs will have
a hard time selling.

The same mentality prevails in people who willingly submit to the
whims of the homeowners' association board. If I want to leave my
garage door open while I use my woodworking tools or work on my car, I
don't want the guy across the street getting his panties in a bunch
over it. Likewise, I don't want to be told when to mow the grass.

Of course, in my case, across the street is 80 acres of Sonoran Desert
and my landscaping is whatever grows here. (I gave the lawnmower to
the guy that bought my last house.) And I'm not trying to keep up
with Jones either because where I live, *I'm* Jones. Heh heh.

|
|Receiving antennas are easily concealed. If you can find mine from the
|street, you were born on Krypton. I think this is an overly-hyped
problem.


If you don't want to hear anything, by all means conceal your antenna.
Antennas are reciprocal, if they wouldn't work well for transmitting,
they will work equally poorly for receiving.

|
|Broadcasting antennas are another animal, though.

Broadcasting is done by broadcasting stations. Broadcasting is
one-way communication.

Hobbists; licensed radio amateurs (hams), and CBers (not to be
confused with hams) are operating transmitting stations designed for
two-way communications.

|For instance, nobody
|wants to live next to some clown running a bunch of linear amps through a
CB
|"base station."

Nobody? That is an all-encompassing term. "Few", "some", "not too
many" might be better. Not that I'm in favor of CBers running illegal
stations.

|It will literally be "seen" on well-shielded cable
|television connections, and is a nuisance.

A "well-shielded" system will not "see" anything of the sort. The
problem will more likely be from some upstanding homeowner, who
wouldn't dare leave his garage door open and violate association
rules, making an illegal tap on the cable.

| I think that's a lot of what the
|"external antenna" rules are meant to curb.

No, most antenna restrictions have nothing to do with the possibility
of interference. The restrictions are for the same reasons as not
wanting the garage door open, the grass an inch too high, painting the
house the wrong shade of white, etc...

On Fri, 21 Nov 2003 21:47:29 -0600, "Stinger"
wrote:

|just as it is clear your intent is to act like
|an asshole.


No, just having a little fun, but some folks take this stuff waaaay
too seriously.

"Stinger" wrote in message
.. .
Sit on a cactus or something, Wes? You seem a little edgy.

Nobody is forced to buy into a neighborhood with covenants. One can do
exactly what you have done and buy some distance from your neighbors.
That's great if it works out for you.

However, my case is obviously different from yours. The home where I now
live is not the home I will own when I retire. I won't need nearly as
many
bedrooms, etc., and it will be out on an acreage I own (that's currently a
little farther than I care to commute to my job). Living in a good
neighborhood with covenants makes sense for me right now, because I do
want
to protect the hefty investment I've made in my home, specifically because
I
do intend to sell it someday.


There are often good communities without covenants, where your property
values do increase and the sale of a home is relatively easy. This lets you
"have your cake and eat it too". You could put up that antenna now and take
it down when it is time to sell.

Dee D. Flint, N8UZE

"Stinger" wrote in message
. ..
Homeowners associations are a good thing! They are basically an
agreement
that you and your neighbors will follow some clearly defined rules for
the
specific purpose of maintining optimum property values for everyone.

Homeowners associations are private governmental authorities which rule
over people who signed away their Constitutional rights! For what --
the promise that othersuch people will pay more later on? Well, maybe
so. This Homeowner Association thing sounds like yet another odious
invention of the New World Order.


In
other words, you won't have to worry about buying an expensive house
and
having your next-door neighbor decide to use his yard to store a dozen
wrecked automobiles while he builds a hot-rod or runs a car-repair
business.
Common sense should tell anyone that their rights end when they start
to
infringe on anyone else's, but sometimes you need it in writing. ;^)

Common sense says there's considerable value in a neighbor who can fix
your car. Especially if you need a Sunday afternoon repair! I've done
plenty of car work, back when I had a driveway. I got along fine with
the neighbors. I suppose fixing their cars helped. We'd talk about
cars, laugh at the Cubs, etc. It's the American way!


Receiving antennas are easily concealed. If you can find mine from
the
street, you were born on Krypton. I think this is an overly-hyped
problem.

Anyone who is bothered by the sight of a wire belongs on another planet.


Broadcasting antennas are another animal, though. For instance,
nobody
wants to live next to some clown running a bunch of linear amps
through a CB
"base station." It will literally be "seen" on well-shielded cable
television connections, and is a nuisance. I think that's a lot of
what the
"external antenna" rules are meant to curb.

-- Stinger


External antenna rules and the rest are meant to intimidate lily-livered
weenies who won't help fix their cars but are happy to sign away their
Constitutional rights.

And if some radio operator is splattering all over, there's plenty of
Real Governmental Authority to answer to.

Frank Dresser

Frank,

As I mentioned to Wes, nobody forces you to buy into a neighborhood with
covenants. I also mentioned that they are not for everybody. In my case,
they are a good idea, and one of the reasons I built my house where I did
was specifically because I knew what to expect from neighbors as they built
nearby.

I don't feel bad that I can't let my yard get waist high, park junk cars on
the lawn, or paint my roof purple. Rather, I feel good knowing my neighbor
won't.

By the way, I happen to be a Republican Kung-Fu black belt (Dragon Claw
1992) that knows a good, honest mechanic that helped me teach my son how to
change the heads on his antique T-Bird in his garage.

So much for your lily-livered weenie who won't fix their own car argument.

I honestly don't understand the hostility in your tone, Frank. What's the
real problem?

-- Stinger



"Frank Dresser" wrote in message
...

"Stinger" wrote in message
. ..
Homeowners associations are a good thing! They are basically an
agreement
that you and your neighbors will follow some clearly defined rules for
the
specific purpose of maintining optimum property values for everyone.

Homeowners associations are private governmental authorities which rule
over people who signed away their Constitutional rights! For what --
the promise that othersuch people will pay more later on? Well, maybe
so. This Homeowner Association thing sounds like yet another odious
invention of the New World Order.


In
other words, you won't have to worry about buying an expensive house
and
having your next-door neighbor decide to use his yard to store a dozen
wrecked automobiles while he builds a hot-rod or runs a car-repair
business.
Common sense should tell anyone that their rights end when they start
to
infringe on anyone else's, but sometimes you need it in writing. ;^)

Common sense says there's considerable value in a neighbor who can fix
your car. Especially if you need a Sunday afternoon repair! I've done
plenty of car work, back when I had a driveway. I got along fine with
the neighbors. I suppose fixing their cars helped. We'd talk about
cars, laugh at the Cubs, etc. It's the American way!


Receiving antennas are easily concealed. If you can find mine from
the
street, you were born on Krypton. I think this is an overly-hyped
problem.

Anyone who is bothered by the sight of a wire belongs on another planet.


Broadcasting antennas are another animal, though. For instance,
nobody
wants to live next to some clown running a bunch of linear amps
through a CB
"base station." It will literally be "seen" on well-shielded cable
television connections, and is a nuisance. I think that's a lot of
what the
"external antenna" rules are meant to curb.

-- Stinger


External antenna rules and the rest are meant to intimidate lily-livered
weenies who won't help fix their cars but are happy to sign away their
Constitutional rights.

And if some radio operator is splattering all over, there's plenty of
Real Governmental Authority to answer to.

Frank Dresser