Cecil Moore wrote:

...
My Webster's unabridged dictionary gives the following
examples of the correct way to pluralize numbers.

"figure 8's", "the 1890's", "the 20's"

73 is a number that stands for "Best Regards"

73's would be "Lots of Best Regards".

A friend of mine is a dispatcher for police/fire/ambulance/etc., in my
area. Her 10 code often requires her to use the "10-73" from this ten
code--which is a "smoke report."

So, thanks for clarifying this for me. I simply took the 73's on many
of the posts sigs as a sign they were "blowing smoke" (actually, "Lots
of smoke!" :-) ), and giving me fair warning! straight-face

Regards,
JS

In article tonline, Roy Lewallen wrote:


Rich Grise wrote:
On Thu, 20 Nov 2008 15:30:26 -0800, Roy Lewallen wrote:
GregS wrote:
Ever hear of the BOW TIE. Its a sort of Fractal antenna. Having a wide
band. It could be improved by making it a full fractal.
That's interesting. In what way(s) is it improved by making it fractal?
How much is the improvement? Can you point me to a reference about this
which gives some quantitative data?



http://www.google.com/search?hl=en&q...oogle+ Search
&aq=f&oq=

Hope This Helps!
Rich

Sorry, it doesn't. Among the claims, trolls for investors, and
testimonials, where is the quantitative data showing that a fractal
antenna is in any way better than a bow tie, in what ways, and how much?
In other words, exactly where is the evidence on which you based your
statement?

Roy Lewallen, W7EL

I don't have data. I think the home made TV antenna in the video, is very much like a bow tie,
and could have better bandwidth by making the elements different lengths. The gain factor
is going to be narrow band since the feed length is constant. I would have also used 12ga
copperweld or solid copper. You can also get closer to fractal by using many more different
sized elements.

greg

"NoSPAM" wrote in message ...

"Joel Koltner" wrote in message
...
Thanks for the details, Barry... tell me though, then, is a discone just
a biconical with a ground plane used to create the (image of the) missing
cone?

Yes. It will have less gain than a biconical and the bandwidth is
slightly more restrictive too. But it is much easier to construct!

73, Barry WA4VZQ


All else being equal, a lossless 'ground plane' type antenna, be it a
monopole developed from a dipole or a discone developed from a biconical
dipole, over an infinite ground plane should exhibit 3 dB _more_ gain than
the symmetrical 'parent' form of antenna. This is because its radiation
pattern is limited to half the solid angle of the parent (e.g. only the
space above the ground plane). Then for a given number of watts fed into
the antenna, the power-flux density must be greater in the region where it
can radiate. In practice, the ground plane isn't infinite so there is some
'undercutting' of the vertical radiation pattern, but the gain should still
be somewhat greater.

The apex angle of the cone in a discone can be chosen to yield 50 ohms
terminal resistance over part of its usable bandwidth, and that angle is
different from the apex angle(s) needed in a biconical dipole for the same
impedance. The usable bandwidth is always limited by the limited
flare-length of the cone(s) and usually also by the accuracy of the apex or
apices where termination is made.

Chris

If you are a member of IEEE, you can access this paper:

Multiband behavior of wideband Sierpinski fractal bow-tie antenna

And if you aren't a member, you aren't in on the joke?

With all the added capacitance to the elements, I have little doubt that
there would be lots of resonance's, and it would be cool to choose the
geometry to bring about the proper feed point impedances, but these things
can never be gainful with all the losses introduced.

Neat idea for specific applications like little pocket toys, but certainly
not the answer to everything.

I wonder how the Limo's will deal with DTV in motion.

I don't have data. I think the home made TV antenna in the video, is very
much like a bow tie,

Comparable to a 4 bay bowtie. Maybe 6db gain. Brazing rod would be a
little lighter and wouldn't rust. Would work much with a reflecting plane
and above the house clutter.

Twin lead could make a comeback since there won't be such a worry about the
low band interference issue. Actually much less loss than coax. I may yet
change over to 300 ohm window line on my bigazz deep fringe at 40ft and
switch it to the ham shack for 6/2m SSB work and DTV DX. TV DX won't be
dead, you will just have to know where to find it

"mpm" wrote in message
...
"Whitespace devices will also cause great harm to wireless microphones,
particularly older models."

Isn't the estimate that something like 90% of all wireless mics are being used
by folks who technically never had the authorization to use the spectrum
(...that is used...) is the first place? Something like how only radio and TV
stations had the authority to use the standard wireless mic frequencies, but
these days anyone doing professional sound for theater, sporting events, etc.
is also using those same frequencies?

On Fri, 21 Nov 2008 16:26:27 -0000, "christofire"
wrote:

The apex angle of the cone in a discone can be chosen to yield 50 ohms
terminal resistance over part of its usable bandwidth, and that angle is
different from the apex angle(s) needed in a biconical dipole for the same
impedance. The usable bandwidth is always limited by the limited
flare-length of the cone(s) and usually also by the accuracy of the apex or
apices where termination is made.

Hi Chris,

This needs heavy qualification, and probably too much such that a
graphical treatment would outweigh the words for contribution:
http://www.qsl.net/kb7qhc/antenna/Discone/discone.htm

73's
Richard Clark, KB7QHC

Twin lead could make a comeback since there won't be such a worry about the
low band interference issue. Actually much less loss than coax.

Maybe... when it's new, of the right type (e.g. tubular), clean, dry,
and carefully installed.

My understanding is that the performance of 300-ohm twinlead
installations tends to deteriorate significantly after a few years
(sunlight and ozone attacks the twinlead, and dirt and pollution
builds up) and during wet weather.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

In article , (Dave Platt) wrote:
Twin lead could make a comeback since there won't be such a worry about the
low band interference issue. Actually much less loss than coax.

Maybe... when it's new, of the right type (e.g. tubular), clean, dry,
and carefully installed.

My understanding is that the performance of 300-ohm twinlead
installations tends to deteriorate significantly after a few years
(sunlight and ozone attacks the twinlead, and dirt and pollution
builds up) and during wet weather.


Last time I used twinlead, except for fiddling around, was on the family
TV antenna installation using an Allied Radio Corodized VHF antenna,
with Beldon Super Permaohm 300 ohm shielded twinlead. Good stuff.

greg

On Thu, 20 Nov 2008 16:58:46 -0800, Roy Lewallen wrote:
Rich Grise wrote:
On Thu, 20 Nov 2008 15:30:26 -0800, Roy Lewallen wrote:
GregS wrote:
Ever hear of the BOW TIE. Its a sort of Fractal antenna. Having a wide
band. It could be improved by making it a full fractal.
That's interesting. In what way(s) is it improved by making it fractal?
How much is the improvement? Can you point me to a reference about this
which gives some quantitative data?

http://www.google.com/search?hl=en&q...earch&aq=f&oq=

Sorry, it doesn't. Among the claims, trolls for investors, and
testimonials, where is the quantitative data showing that a fractal
antenna is in any way better than a bow tie, in what ways, and how much?
In other words, exactly where is the evidence on which you based your
statement?

The only "evidence" I have is a "testimonial" by the guy who invented it,
on some PBS show. And they claimed that that's how they pack so much
antenna into a box the size of your thumb. ;-)

And, having a passing familiarity with fractals, it just sounds eminently
plausible to me. :-)

Cheers!
Rich