John - KD5YI wrote:
Rod Speed wrote:
Geoffrey S. Mendelson wrote

Rod Speed wrote


Is one transmit and the other receive?
Or are they both transmit and receive?


They're normally both transmit and receive.


That's a shame. Here in Israel we are limited to 100mw EIRP, which
severly limits the transmit antenna. There is NO limitation on the
receive antenna.


A receive antenna has no EIRP, it doesnt radiate any real power.




Actually, when properly matched, it radiates half the received power.

Wrong.

Roy Lewallen wrote
Don K wrote
John - KD5YI wrote
Rod Speed wrote

A receive antenna has no EIRP, it doesnt radiate any real power.

Actually, when properly matched, it radiates half the received power.

How do you get that?
If the receiver input impedance is matched to the antenna, all the
received power is absorbed. There is no reflection. There is no
radiation.

If the receiver matching is for optimal noise figure, there may be
some reflection and reradiation, but there's nothing pinning it to
be half the received power.

John is correct.

Nope.

A receiving antenna, when matched, reradiates half the power it receives.

Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

An impinging field induces current in the antenna. This causes radiation, just like the
current in a transmitting antenna. As it turns out, when the antenna is matched, the
amount of power radiated equals the amount of power delivered to the load, and that's
the best you can do.

Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

If you'd like a more in-depth and mathematical explanation, you can find it in any
antenna text, often discussed as "scattering".

Not relevant to the original point, any effect on the EIRP restriction.

If a receiving antenna did absorb all the impinging power, it would be a lot easier to
make a shield or a stealth aircraft.

Not relevant to the original point, any effect on the EIRP restriction.

Rod Speed wrote:
Roy Lewallen wrote
Don K wrote
John - KD5YI wrote
Rod Speed wrote

A receive antenna has no EIRP, it doesnt radiate any real power.

Actually, when properly matched, it radiates half the received power.

How do you get that?
If the receiver input impedance is matched to the antenna, all the
received power is absorbed. There is no reflection. There is no
radiation.

If the receiver matching is for optimal noise figure, there may be
some reflection and reradiation, but there's nothing pinning it to
be half the received power.

John is correct.

Nope.

A receiving antenna, when matched, reradiates half the power it receives.

Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

An impinging field induces current in the antenna. This causes radiation, just like the
current in a transmitting antenna. As it turns out, when the antenna is matched, the
amount of power radiated equals the amount of power delivered to the load, and that's
the best you can do.

Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

If you'd like a more in-depth and mathematical explanation, you can find it in any
antenna text, often discussed as "scattering".

Not relevant to the original point, any effect on the EIRP restriction.

If a receiving antenna did absorb all the impinging power, it would be a lot easier to
make a shield or a stealth aircraft.

Not relevant to the original point, any effect on the EIRP restriction.


Always amazinmg how when some people are proven wrong, the revert to the "Is
NOT, IS NOT," type of argument used by small children, then when that doesn't
work, the argument becomes irrelevant.

Rod, I suggest you LEARN something from your intellectual and technical betters
BEFORE you show the world your ignorance.

John

Rod Speed wrote:
Roy Lewallen wrote
Don K wrote
John - KD5YI wrote
Rod Speed wrote

A receive antenna has no EIRP, it doesnt radiate any real power.

Actually, when properly matched, it radiates half the received power.

How do you get that?
If the receiver input impedance is matched to the antenna, all the
received power is absorbed. There is no reflection. There is no
radiation.

If the receiver matching is for optimal noise figure, there may be
some reflection and reradiation, but there's nothing pinning it to
be half the received power.

John is correct.

Nope.

A receiving antenna, when matched, reradiates half the power it receives.

Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

An impinging field induces current in the antenna. This causes radiation, just like the
current in a transmitting antenna. As it turns out, when the antenna is matched, the
amount of power radiated equals the amount of power delivered to the load, and that's
the best you can do.

Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

If you'd like a more in-depth and mathematical explanation, you can find it in any
antenna text, often discussed as "scattering".

Not relevant to the original point, any effect on the EIRP restriction.

If a receiving antenna did absorb all the impinging power, it would be a lot easier to
make a shield or a stealth aircraft.

Not relevant to the original point, any effect on the EIRP restriction.


Always amazinmg how when some people are proven wrong, the revert to the "Is
NOT, IS NOT," type of argument used by small children, then when that doesn't
work, the argument becomes irrelevant.

Rod, I suggest you LEARN something from your intellectual and technical betters
BEFORE you show the world your ignorance.

John

Rod Speed wrote:
Roy Lewallen wrote
. . .
A receiving antenna, when matched, reradiates half the power it receives.

Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.
. . .

It's real power, but that power all comes from the impinging field; it's
not contributing any new power. So you're right that the EIRP
restriction doesn't apply. The receive antenna reduces the amount of
power in the field by the amount delivered to the antenna's termination,
plus any losses along the way. The intent of the EIRP restriction is to
limit the amount of field strength added by a transmitter.

Roy Lewallen, W7EL

John L. Sielke wrote:
Rod Speed wrote:
Roy Lewallen wrote
Don K wrote
John - KD5YI wrote
Rod Speed wrote

A receive antenna has no EIRP, it doesnt radiate any real power.

Actually, when properly matched, it radiates half the received
power.

How do you get that?
If the receiver input impedance is matched to the antenna, all the
received power is absorbed. There is no reflection. There is no
radiation.

If the receiver matching is for optimal noise figure, there may be
some reflection and reradiation, but there's nothing pinning it to
be half the received power.

John is correct.

Nope.

A receiving antenna, when matched, reradiates half the power it
receives.

Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

An impinging field induces current in the antenna. This causes
radiation, just like the current in a transmitting antenna. As it
turns out, when the antenna is matched, the amount of power
radiated equals the amount of power delivered to the load, and
that's the best you can do.

Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

If you'd like a more in-depth and mathematical explanation, you can
find it in any antenna text, often discussed as "scattering".

Not relevant to the original point, any effect on the EIRP
restriction.

If a receiving antenna did absorb all the impinging power, it would
be a lot easier to make a shield or a stealth aircraft.

Not relevant to the original point, any effect on the EIRP
restriction.

Always amazinmg how when some people are proven wrong, the
revert to the "Is NOT, IS NOT," type of argument used by small
children, then when that doesn't work, the argument becomes irrelevant.

Never ever could bull**** its way out of a wet paper bag.

Rod, I suggest you LEARN something from your intellectual and
technical betters BEFORE you show the world your ignorance.

Never ever could bull**** its way out of a wet paper bag.

While your original was technically correct, its completely
irrelevant to what was actually being discussed, WHETHER
THE RECEIVE ANTENNA EVER RADIATES ENOUGH TO
BE RELEVANT TO THE EIRP RESTRICTION.

Roy Lewallen wrote:
Rod Speed wrote:
Roy Lewallen wrote
. . .
A receiving antenna, when matched, reradiates half the power it
receives.

Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

It's real power,

Yes, BUT NOT IN THE EIRP RESTRICTION SENSE.

but that power all comes from the impinging field; it's not contributing any new power.
So you're right that the EIRP restriction doesn't apply.

And that is what was being discussed when John made such a
spectacular fool of himself mindlessly rabbiting on about what
is no news to anyone with a clue about receiving antennas.

The receive antenna reduces the amount of power in the field by the amount delivered to
the antenna's termination, plus any losses along the way. The intent of the EIRP
restriction is to limit the amount of field strength added by a
transmitter.

Duh. So John was mindlessly rabbiting on about a complete
irrelevancy WHEN THE EIRP RESTRICTION WAS BEING DISCUSSED.

On Sun, 9 Jul 2006 07:12:11 +1000, in alt.internet.wireless , "Rod
Speed" wrote:

John L. Sielke wrote:

Always amazinmg how when some people are proven wrong, the
revert to the "Is NOT, IS NOT," type of argument used by small
children, then when that doesn't work, the argument becomes irrelevant.

Never ever could bull**** its way out of a wet paper bag.

Rod, I suggest you LEARN something from your intellectual and
technical betters BEFORE you show the world your ignorance.

Never ever could bull**** its way out of a wet paper bag.

While your original was technically correct, its completely
irrelevant to what was actually being discussed, WHETHER
THE RECEIVE ANTENNA EVER RADIATES ENOUGH TO
BE RELEVANT TO THE EIRP RESTRICTION.

I've not been following this thread, but I can tell you straight off,
I am significantly more inclined to believe the guys who are not
shouting and hurling abuse.

Make of that what you will, but my suggestion is to counter with
rational argument backed up by references and facts, rather than
insults and obscenities.

--
Mark McIntyre

Mark McIntyre wrote
Rod Speed wrote
John L. Sielke wrote

Always amazinmg how when some people are proven wrong, the
revert to the "Is NOT, IS NOT," type of argument used by small
children, then when that doesn't work, the argument becomes irrelevant.

Never ever could bull**** its way out of a wet paper bag.

Rod, I suggest you LEARN something from your intellectual and
technical betters BEFORE you show the world your ignorance.

Never ever could bull**** its way out of a wet paper bag.

While your original was technically correct, its completely
irrelevant to what was actually being discussed, WHETHER
THE RECEIVE ANTENNA EVER RADIATES ENOUGH TO
BE RELEVANT TO THE EIRP RESTRICTION.

I've not been following this thread, but I can tell you
straight off, I am significantly more inclined to believe
the guys who are not shouting and hurling abuse.

You have always been, and always will be, completely and utterly irrelevant.

What you may or may not be inclined to believe in spades.

Anyone with a clue considers the facts, not the style stuff, ****wit.

Make of that what you will,

I flush it where it belongs.

but my suggestion is to counter with rational
argument backed up by references and facts,

Dont need 'references' on that basic fact that even
when the receiving antenna does reradiate about
half of what it receives, THAT IS COMPLETELY
IRRELEVANT TO THE LEGISLATED ERIP LEVEL.

rather than insults and obscenities.

I suggest you take your stupid suggestion
and shove it up your arse, where it belongs.

"Roy Lewallen" wrote in message ...
Don K wrote:
"John - KD5YI" wrote in message news:XLQrg.2896$bd4.372@trnddc01...
Rod Speed wrote:
A receive antenna has no EIRP, it doesnt radiate any real power.
Actually, when properly matched, it radiates half the received power.


How do you get that?
If the receiver input impedance is matched to the antenna, all the
received power is absorbed. There is no reflection. There is no radiation.

If the receiver matching is for optimal noise figure, there may be
some reflection and reradiation, but there's nothing pinning it to
be half the received power.

John is correct. A receiving antenna, when matched, reradiates half the power it receives. An
impinging field induces current in the antenna. This causes radiation, just like the current in a
transmitting antenna. As it turns out, when the antenna is matched, the amount of power radiated
equals the amount of power delivered to the load, and that's the best you can do. If you'd like a
more in-depth and mathematical explanation, you can find it in any antenna text, often discussed
as "scattering".

If a receiving antenna did absorb all the impinging power, it would be a lot easier to make a
shield or a stealth aircraft.

Roy Lewallen, W7EL

Maybe to some extent, it's a matter of nit-picking over what
"received power" means. You can think of an antenna as having an
effective aperture size over which it captures all the energy
crossing that cross-sectional area. To me it's logical to think
of "received power" as the power that actually gets scooped
up and delivered.

Effective aperture increases with antenna gain. Obviously something
like a dipole has a relatively small effective aperture. But the
effective aperture of a high-gain horn antenna for instance, will
approach its actual physical cross-sectional area.

For instance, look at Figure 13 in this pdf.
http://www.coe.montana.edu/ee/rwolff...WBAntennas.pdf

Don