JJ wrote:

Dick Carroll wrote in message ...

Don't pay them too much attention, Bruce. Neither JJ nor TwIT realizes
they were NOT using a 1/4 wave dipole. If they had been, neither would
have gotten a signal out of the back yard.

If the *antenna system* took a load and performed under the circumstances
they describe, then both JJ and TwIT were loading the outer surface of the
coax shield, and *that* was doing a major part of the radiating.

Of course when one side of a 1/4 wave dipole is attached to the braid
of the coax with no decoupling, then the dipole is no longer a 1/4 wave
dipole! What it becomes then depends entirely on
the feedline length as well as other local factors. So then it will
probably take some load, and maybe even load up to full supplied power,
as JJ described. At that point it's a crap shoot-you don't know *what*
you've got! For sure it ISN'T a 1/4 wave dipole! But the uninformed will
think their "1/4 wave dipole" worked just fine!

If JJ had used a good isolation choke or 1:1 balun to decouple the coax

from the 40 meter dipole at the feedpoint the tuner would have balked big

time, and all that RF would have bounced around inside it, and made
itself known quite loudly in the form of arcs.


The 40 meter dipole does have an HF 1:1 balun at the feedpoint.



The KWM-2 finals might
have sparked a bit, too.


Why? As far as the M-2 was concerned, it was seeing a good match, courtesy
of the tuner (that is one function the tuner performs in case you didn't
know). There was no arcing anywhere...have no idea what the swr was on the
feedline, but that is not the point. The point is, I did get a signal out
and made contacts, all with good readability on both ends. I have never
claimed this would make a good antenna or that one should operate such, just
proved that it can work to some extent. I thought you were smarter than
dannyboy but guess not.

I'll admit stupidity if you can explain how and why that antenna worked
as a quater wave dipole.

I already presented some fairly comprehensive data on why it wouldn't.
That was pretty basic stuff.

That a quarter wave dipole antenna would work is fairly extraordinary.

Present your evidence and your theory/rationale.

- Mike KB3EIA -

"Mike Coslo" wrote in message
. ..
JJ wrote:

Dick Carroll wrote in message ...

Don't pay them too much attention, Bruce. Neither JJ nor TwIT realizes
they were NOT using a 1/4 wave dipole. If they had been, neither would
have gotten a signal out of the back yard.

If the *antenna system* took a load and performed under the
circumstances
they describe, then both JJ and TwIT were loading the outer surface of
the
coax shield, and *that* was doing a major part of the radiating.

Of course when one side of a 1/4 wave dipole is attached to the braid
of the coax with no decoupling, then the dipole is no longer a 1/4 wave
dipole! What it becomes then depends entirely on
the feedline length as well as other local factors. So then it will
probably take some load, and maybe even load up to full supplied power,
as JJ described. At that point it's a crap shoot-you don't know *what*
you've got! For sure it ISN'T a 1/4 wave dipole! But the uninformed will
think their "1/4 wave dipole" worked just fine!

If JJ had used a good isolation choke or 1:1 balun to decouple the coax

from the 40 meter dipole at the feedpoint the tuner would have balked
big

time, and all that RF would have bounced around inside it, and made
itself known quite loudly in the form of arcs.


The 40 meter dipole does have an HF 1:1 balun at the feedpoint.



The KWM-2 finals might
have sparked a bit, too.


Why? As far as the M-2 was concerned, it was seeing a good match,
courtesy
of the tuner (that is one function the tuner performs in case you didn't
know). There was no arcing anywhere...have no idea what the swr was on
the
feedline, but that is not the point. The point is, I did get a signal
out
and made contacts, all with good readability on both ends. I have never
claimed this would make a good antenna or that one should operate such,
just
proved that it can work to some extent. I thought you were smarter than
dannyboy but guess not.

I'll admit stupidity if you can explain how and why that antenna worked
as a quater wave dipole.

I already presented some fairly comprehensive data on why it wouldn't.
That was pretty basic stuff.

That a quarter wave dipole antenna would work is fairly extraordinary.

Present your evidence and your theory/rationale.

- Mike KB3EIA -


Probably for the same reason loading up house plumbing will work, or loading
up a coat hanger, or whatever. With a tuner, and with other apparatuses in
use or not, coupling--whatever you want to call it--if a signal gets out, it
gets out and that is all that counts *sometimes.*

Kim W5TIT

Probably for the same reason loading up house plumbing will work, or loading
up a coat hanger, or whatever. With a tuner, and with other apparatuses in
use or not, coupling--whatever you want to call it--if a signal gets out, it
gets out and that is all that counts *sometimes.*

Kim W5TIT

And of course this has no reference to 1/4 Wave dipole

Kim W5TIT wrote:
"Mike Coslo" wrote in message

some snippage

I already presented some fairly comprehensive data on why it wouldn't.
That was pretty basic stuff.

That a quarter wave dipole antenna would work is fairly extraordinary.

Present your evidence and your theory/rationale.

- Mike KB3EIA -



Probably for the same reason loading up house plumbing will work, or loading
up a coat hanger, or whatever. With a tuner, and with other apparatuses in
use or not, coupling--whatever you want to call it--if a signal gets out, it
gets out and that is all that counts *sometimes.*

The idea of using a random length of wire or the rain gutter is a time
honored method of making an emergency/stealth or just plain experimental
antenna. Tuners often make these antennas work - some ok, some not so
well. And a large part of the not so good operation is when the tuner
can't match the antenna.

My MFJ949 tuner manual has several lengths that the user is encouraged
to avoid. According to them they are the worst possible line lengths:

160 meter dipole - 130 feet

80 meter dipole - 66 feet

40 meter dipole - 32 feet

If you do the calculations, you'll see what fractional wavelength those
antennas are for the respective bands.

note: if anyone looks up the MFJ info, they will see a few other
frequencies also on the "do not use" list. These are odd multiples of
1/4 wavelength, so I left them out of this discussion. But in general,
its a related problem - odd multiples of 1/4 wave are not so hot to use.

They note that if you have trouble tuning an antenna on a frequency you
want to use, you should shorten or lengthen the antenna by 1/8th
wavelength. Then you should be able to get the tuner to match things up.

- Mike KB3EIA -