On Mon, 05 Apr 2004 06:02:56 GMT, "Jerry Martes"
wrote:


"Dan Richardson @mendolink.com" ChangeThisToCallSign wrote in message
.. .
On Sun, 4 Apr 2004 22:12:24 -0500, "H. Adam Stevens, NQ5H"
wrote:

You just can't beat a resonant antenna for radiation.

Eh? You mean a 1¼-wave (non-resonate) dipole radiates less than a
¼-wave resonate dipole?

Strange in that a 1¼-wave dipole has 3 dBd gain.

Danny, K6MHE

Danny

Do antennas have gain or do they have directivity?

Jerry


Both

Danny

Jerry Martes wrote:

Do antennas have gain or do they have directivity?

From Balanis: "Although the gain of an antenna is closely
related to the directivity, gain is a measure that takes into
account the efficiency of the antenna as well as the
directional properties of the antenna, and it is therefore
controlled only by the pattern."
--
73, Cecil, W5DXP



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"Do antennas have gain or do they have directivity?"
============================
What a wierd question! These are not mutally exclusive properties.

73 de Jack, K9CUN

"Dan Richardson @mendolink.com" ChangeThisToCallSign wrote in message
...
On Sun, 4 Apr 2004 22:12:24 -0500, "H. Adam Stevens, NQ5H"
wrote:

You just can't beat a resonant antenna for radiation.

Eh? You mean a 1¼-wave (non-resonate) dipole radiates less than a
¼-wave resonate dipole?

Strange in that a 1¼-wave dipole has 3 dBd gain.

Danny, K6MHE


Antenna resonance implies a purely resistive impedance at the feed point.
Both 1/2 wave and 3/2 wave dipoles are resonant.
I don't know what a "1/4-wave resonate dipole" is.
A dipole is 1/2 wavelength long at it's fundamental resonant frequency.
"Gain" is merely a re-distribution of the radiation pattern.
73
H.
NQ5H

On Mon, 5 Apr 2004 06:30:15 -0500, "H. Adam Stevens, NQ5H"
wrote:


"Dan Richardson @mendolink.com" ChangeThisToCallSign wrote in message
.. .
On Sun, 4 Apr 2004 22:12:24 -0500, "H. Adam Stevens, NQ5H"
wrote:

You just can't beat a resonant antenna for radiation.

Eh? You mean a 1¼-wave (non-resonate) dipole radiates less than a
¼-wave resonate dipole?

Strange in that a 1¼-wave dipole has 3 dBd gain.

Danny, K6MHE


Antenna resonance implies a purely resistive impedance at the feed point.
Both 1/2 wave and 3/2 wave dipoles are resonant.
I don't know what a "1/4-wave resonate dipole" is.
A dipole is 1/2 wavelength long at it's fundamental resonant frequency.
"Gain" is merely a re-distribution of the radiation pattern.
73
H.
NQ5H


Sorry.. a typo should be 1¼-wave non-resonte dipole.

Danny

On Mon, 5 Apr 2004 06:30:15 -0500, "H. Adam Stevens, NQ5H"
wrote:


"Dan Richardson @mendolink.com" ChangeThisToCallSign wrote in message
.. .
On Sun, 4 Apr 2004 22:12:24 -0500, "H. Adam Stevens, NQ5H"
wrote:

You just can't beat a resonant antenna for radiation.

Eh? You mean a 1¼-wave (non-resonate) dipole radiates less than a
¼-wave resonate dipole?

Strange in that a 1¼-wave dipole has 3 dBd gain.

Danny, K6MHE


Antenna resonance implies a purely resistive impedance at the feed point.
Both 1/2 wave and 3/2 wave dipoles are resonant.
I don't know what a "1/4-wave resonate dipole" is.
A dipole is 1/2 wavelength long at it's fundamental resonant frequency.
"Gain" is merely a re-distribution of the radiation pattern.
73
H.
NQ5H


Well, I'll try it again..... still a typo I meant to say "a ½-wave
resonate dipole".. Sorry

In other words I press Alt+172 instead of Alt+171

Danny

H. Adam Stevens, NQ5H wrote:

"Dan Richardson @mendolink.com" ChangeThisToCallSign wrote:
Strange in that a 1¼-wave dipole has 3 dBd gain.

I don't know what a "1/4-wave resonate dipole" is.

Look again, Danny said a 1.25 WL dipole, a non-resonant length
dipole known as an extended-double-Zepp and known to have about
3 dB gain over your 1/2WL resonant dipole. With about a 0.2WL
series section transformer made out of open-wire line, the
non-resonant EDZ resonates as a system and will beat your
resonant 1/2WL dipole in its favored direction.
--
73, Cecil, W5DXP



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Someone sed,

"You just can't beat a resonant antenna for radiation."
===================

PHOOEY! Some of the best antennas are NOT resonant, and shouldn't be.

I use my 130-ft doublet on 40 m where it is one wavelength long. Has
theoreitical gain of about 1.8 dB. This is NOT a resonant antenna.

73 de Jack, K9CUN

Sure. check virtually any ARRL Handbook for plans, and start making the
rounds of local ham swap meets...

73,
Mike KI6PR
El Rancho R.F., CA

"Matthew&Wendy" wrote
Instead of buying an antenna tuner, is it possible to build one myself.
Nothing fancy, but a rotary switch and some ?capacitors?. Thanks for the
advice.

Matthew


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