tom wrote:
Note that none of these are particularly close to resonance at the
design frequency.

Yagis do have a resonant frequency but that frequency
is not at the design frequency. At the resonant frequency,
the forward gain and F/B ratio are not optimum. At the
optimum forward gain frequency and/or F/B ratio frequency,
the Yagi, sans matching network, is not resonant.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

Cecil Moore wrote:
tom wrote:
Note that none of these are particularly close to resonance at the
design frequency.

Yagis do have a resonant frequency but that frequency
is not at the design frequency. At the resonant frequency,
the forward gain and F/B ratio are not optimum. At the
optimum forward gain frequency and/or F/B ratio frequency,
the Yagi, sans matching network, is not resonant.

Agreed, although it has become popular to make designs with about 50+j0
driven elements lately. I think it's to make them simpler and lighter
because, as you say, the other characteristics are not optimum if you do.

tom
K0TAR

On Wed, 23 Sep 2009 07:16:49 -0500, tom wrote:

Cecil Moore wrote:
tom wrote:
Note that none of these are particularly close to resonance at the
design frequency.

Yagis do have a resonant frequency but that frequency
is not at the design frequency. At the resonant frequency,
the forward gain and F/B ratio are not optimum. At the
optimum forward gain frequency and/or F/B ratio frequency,
the Yagi, sans matching network, is not resonant.

That's about as useful as saying you do not obtain the maximum miles
per gallon in your car when the ashtray is half full or when the
carpets are at their optimal brushed out nap.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
That's about as useful as saying you do not obtain the maximum miles
per gallon in your car when the ashtray is half full or when the
carpets are at their optimal brushed out nap.

Nope, it's as useful as saying one cannot get the
advertised miles per gallon when one is driving
the car uphill at 80 mph. Miles per gallon is
related to incline and speed. Frequency, gain,
and F/B ratio are related. I surprised you don't
know that.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

Richard Clark wrote:
On Wed, 23 Sep 2009 07:16:49 -0500, tom wrote:

Cecil Moore wrote:
tom wrote:
Note that none of these are particularly close to resonance at the
design frequency.
Yagis do have a resonant frequency but that frequency
is not at the design frequency. At the resonant frequency,
the forward gain and F/B ratio are not optimum. At the
optimum forward gain frequency and/or F/B ratio frequency,
the Yagi, sans matching network, is not resonant.

That's about as useful as saying you do not obtain the maximum miles
per gallon in your car when the ashtray is half full or when the
carpets are at their optimal brushed out nap.

73's
Richard Clark, KB7QHC

Nice attribution to me Richard, but Cecil wrote it.

And it makes a lot more sense than your statement, although he could
have worded it better.

tom
K0TAR

tom wrote:
And it makes a lot more sense than your statement, although he could
have worded it better.

Sorry, sometimes I write in Texan rather than English.:-)
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

Cecil Moore wrote:
tom wrote:
And it makes a lot more sense than your statement, although he could
have worded it better.

Sorry, sometimes I write in Texan rather than English.:-)

Apology accepted. And I know you can't help it.