[Elecraft] Re:Alligators and Bats

Thu Jan 10 17:49:16 2002

May I express a second opinion, Lou?

*My* (ARRL) Antenna book says the gain of a real-world dipole is 2.14dB
below an isotropic source.  I don't recall any discussions about dipoles in
free space, so can't comment on your 8 and ~6dB figures.  But all of the
gain figures I remember seeing were either based on an isotropic source,
which can raise unrealistic expectations among amateurs, or a real-world
dipole.

We agree a dipole's main lobe can be higher than a vertical, but probably
not on it still having more gain at low angles than a vertical,
whose main lobe is inherently low angle.  I'm talking "good" verticals, not
your out-of-the-box trap job clamped to a fence post with no ground system.

If your opinion of verticals is that bad, you've probably been using GAP
products without radials... or equivalent.  For the past decade or so, I've
used Hy-Gain Hy-Towers, 52-foot tall verticals without traps, with
decent -not perfect- ground systems.  My two current Hy-Towers (I plan to
phase 'em one day) each have 3 ground rods and 45, 45-foot radials under
them.  They're fed with the lowest-loss non-hardline I could find,
weatherproofed.
They won't compete with a good beam, and they're comatose close in,
but out some distance... 500 miles or so on 40 meters for example... a
Hy-Tower will equal or outperform any dipole I've ever been able to erect,
and that's quite a few from 30 to 65 feet up.  They do a very good job on DX
on all bands.

I do have an 80/40meter inverted vee for contacts within my state, and by
the way, it is frequently MORE noisy than my Hy-Towers. Verticals being
inherently noisier than horizontals is a myth.  Of course a noisy location
can make them so.

But then differences of opinion are what makes the world go 'round and
allows a variety of brands and styles to continue to be popular.

73 (preparing to dodge slings and arrows!!)... Ed, W5EJ

----- Original Message -----
From: "lhlousek" <[email protected]>
To: "George, W5YR" <[email protected]>; <[email protected]>
Cc: <[email protected]>
Sent: Thursday, January 10, 2002 1:01 PM
Subject: Re: [Elecraft] Re:Alligators and Bats

> <<So, what "wire antennas" do you recommend to obtain "antenna gain?">>
>
> A dipole at 1/2 wave over average ground can have a gain of about 8 dBi or
~ 6
> dBd. (that's 6 dB over a dipole in free space).  That's way better than
any
> vertical or array of verticals I've seen analyzed except for those on salt
> water.  Of course the elevation angle of the main lobe of the dipole may
be a
> higher but it still usually has more gain an low angles than do verticals.
>
> Lou
>
>
>
>
>
> ----- Original Message -----
> From: "George, W5YR" <[email protected]>
> To: <[email protected]>
> Cc: <[email protected]>
> Sent: Thursday, January 10, 2002 11:47 AM
> Subject: Re: [Elecraft] Re:Alligators and Bats
>
>
> >
> >
> > [email protected] wrote:
> > >
> > > Just remember any signal is only as good as its antenna.  Try to run a
gain
> > > antenna whenever possible, especially if you are QRP.  Yes, the K2
does hear
> > > better but antenna gain cannot be overlooked; use wire antennas!
> >
> > Rod, could you elaborate on this point a little? Few people using wire
> > antennas can achieve much if any gain over a dipole since they seldom
have
> > the room and other facilities required to erect a wire beam or a
steerable
> > array of some sort.
> >
> > I use a pair of 20-meter EDZ's mounted at right angles to take advantage
of
> > the directivity but the gain, except on 20 where it is 3 db, is
negligible
> > on 40, for example.
> >
> > So, what "wire antennas" do you recommend to obtain "antenna gain?"
> >
> > 72/73/oo, George W5YR - the Yellow Rose of Texas
> > Fairview, TX 30 mi NE of Dallas in Collin county EM13qe
> > Amateur Radio W5YR, in the 56th year and it just keeps getting better!
> > QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771
> > Icom IC-756PRO #02121  Kachina #91900556  IC-765 #02437
> >
> > All outgoing email virus-checked by Norton Anti-Virus 2002
> >
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