who where wrote:
On Wed, 04 Nov 2009 20:10:53 -0600, tom wrote:

who where wrote:
I suspect that the design of the MFJ antenna was done in a way which
places the parasitic elements close enough to reduce the folded
dipole's impedance to somewhere in the neighborhood of 50 ohms. All
that would be necessary, then, to allow a direct feed from a 50-ohm
coax, would be a choke balun (to convert the unbalanced coax feed to a
balanced drive to the folded dipole, without altering the impedance).
The presense and spacing of the parasitic elements isn't going to
change the feedpoint impedance that much.
Wrong. It can change it a lot. It can take a 50 ohm DE and move it to
10 ohms or less. And then there's the reactive part.

Well you can believe what you like.

I believe what occurs and is measurable.

tom
K0TAR

On Thu, 05 Nov 2009 21:52:18 -0600, tom wrote:

Well you can believe what you like.

I believe what occurs and is measurable.

Hi Tom,

It's amazing how after a period of silence, BOTH Art and Jaro pop up
at the same time.

Does Art have an antipodes sock-puppet?

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Thu, 05 Nov 2009 21:52:18 -0600, tom wrote:

Well you can believe what you like.
I believe what occurs and is measurable.

Hi Tom,

It's amazing how after a period of silence, BOTH Art and Jaro pop up
at the same time.

Does Art have an antipodes sock-puppet?

73's
Richard Clark, KB7QHC

Well, I've been silent also. And for almost the same time period. I
could be both of them. I do have 2 feet.

tom
K0TAR

On Thu, 05 Nov 2009 22:20:32 -0600, tom wrote:

I do have 2 feet.

But not one of them in Perth.

On Thu, 05 Nov 2009 22:24:44 -0800, Richard Clark
wrote:

On Thu, 05 Nov 2009 22:20:32 -0600, tom wrote:

I do have 2 feet.

But not one of them in Perth.

No relation to anyone you are thinking_of/describing/etc, sorry to
ruin your conspiracy theory.

If you want to try and achieve a match to 50 ohms by moving the
adjacent parasitic elements seriously close to the driven folded
dipole, go for it. (I could dust off trusty Elnec and get a result.)
But I'd be surprised if anyone who gives a rats about the consistency
of the result would go down that path.

I am very familair with how the commercial side-mounted dipoles and
yagis are manufactured here in Australia, and I doubt that the rest of
the world is dramatically different. In three simple words - series
coax transformer. Let's agree that with an SMD you don't have
parasitics to play around with - except for tower spacing (which has
an impact on pattern, and variations are used for that end.) The
Aussie manufacturers use eaxactly the same method on the FD on their
yagis. That is why I suggested the O/P look into that approach.

On Fri, 06 Nov 2009 15:49:46 +0800, who where wrote:

But not one of them in Perth.

No relation to anyone you are thinking_of/describing/etc, sorry to
ruin your conspiracy theory.

Your confirmation here doesn't ruin anything. Art would hug you no
matter how you sign. Those he does have a remarkable need for
retaining anonymity. He would have us believe it's because his
supporters are easily bruised in the jostle. The following comment
would support that:

...gives a rats about the consistency
of the result would go down that path.

which is another but perhaps left-handed confirmation.

73's
Richard Clark, KB7QHC

On Fri, 06 Nov 2009 08:18:49 -0800, Richard Clark
wrote:

On Fri, 06 Nov 2009 15:49:46 +0800, who where wrote:

But not one of them in Perth.

No relation to anyone you are thinking_of/describing/etc, sorry to
ruin your conspiracy theory.

Your confirmation here doesn't ruin anything. Art would hug you no
matter how you sign. Those he does have a remarkable need for
retaining anonymity. He would have us believe it's because his
supporters are easily bruised in the jostle. The following comment
would support that:

...gives a rats about the consistency
of the result would go down that path.

which is another but perhaps left-handed confirmation.

73's
Richard Clark, KB7QHC

Whatever - and whoever Art is. I wonder why people like you carry on
at a personal level towards posters whose views you don't share. And
you seem to need the limelight, posting a name and callsign.

I'm describing how the matching IS done commercially. You can crap on
forever if you wish about how you might do it. Fini.