Thanks, Jim!
Have a good Sunday afternoon/evening!
73,
Charlie, K4OTV
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of James
Rodenkirch
Sent: Sunday, September 08, 2013 3:53 PM
To: Charlie Cunningham; 'Carl'; 'Mike Armstrong'; 'Tom W8JI'; 'Shoppa, Tim';
w7dra@juno.com
Cc: topband@contesting.com
Subject: Re: Topband: 5/8 wavelength vertical is mo betta than
shorterversions??
Great job, Charlie AND on the opening weekend of the NFL season, none the
less! You are Da Man, ma Mon - you are carrying the water for this "event"
and I appreciate your efforts! Jim R. K9JWV
> From: charlie-cunningham@nc.rr.com
> To: km1h@jeremy.mv.com; rodenkirch_llc@msn.com; armstrmj@aol.com;
w8ji@w8ji.com; tshoppa@wmata.com; w7dra@juno.com
> CC: topband@contesting.com
> Subject: RE: Topband: 5/8 wavelength vertical is mo betta than
shorterversions??
> Date: Sun, 8 Sep 2013 15:08:47 -0400
>
> I'll do the 3/8 wave case later, Carl. I didn't have time to get back to
it
> today because I got all bolluxed up trying to include an attachment to my
> reflector post. Also, even trying to embed the document in the body of a
> reflector post didn't seem to work. Must have made the posting too large
for
> the reflector to accept.
>
> Later,
>
> Charlie, K4OTV
>
> -----Original Message-----
> From: Carl [mailto:km1h@jeremy.mv.com]
> Sent: Sunday, September 08, 2013 12:24 PM
> To: Charlie Cunningham; 'James Rodenkirch'; 'Mike Armstrong'; 'Tom W8JI';
> Shoppa, Tim; w7dra@juno.com
> Cc: topband@contesting.com
> Subject: Re: Topband: 5/8 wavelength vertical is mo betta than
> shorterversions??
>
> Include the 3/8 wave while you are at it.
> And thank you for doing this.
>
> Carl
> KM1H
>
>
>
> Subject: Re: Topband: 5/8 wavelength vertical is mo betta than
> shorterversions??
>
>
> > Jim, Mike et al:
> >
> > I've been putting together a document along with some models, plots etc.
> > that addresses the 1/4, 1/2, 5/8 wave vertical question, and I hope,
> > illustrates where some of the confusion arises - especially with regard
to
> > the 5/8 wave case. The answers are not so simple in that case, and are
> > dependent on distance, frequency, time of day, and ionospheric
conditions.
> > Please keep your cool and bear with me. Maybe we can shed some light on
> > this
> > complex issue, with a little less heat and cussin' and discussin'! I'll
> > post
> > the document on the reflector as an e-mail attachment.
> >
> > 73,
> > Charlie, K4OTV
> >
> > -----Original Message-----
> > From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of James
> > Rodenkirch
> > Sent: Sunday, September 08, 2013 11:00 AM
> > To: Mike Armstrong; Tom W8JI
> > Cc: topband@contesting.com
> > Subject: Re: Topband: 5/8 wavelength vertical is mo betta than shorter
> > versions??
> >
> > Mike: I apologize if my query came across as an insult!! Mea culpa sent
> > from out here in the black hole of 160 meter communications - s/w Utah.
> > I think I said I wasn't doubting your claim and I wasn't questioning
your
> > "conclusions" - just attempting to find some modeling or Measures of
> > Performance to substantiate it as, lately, I have been seeing/reading of
> > anecdotal "evidence" and I, for one, am interested in supporting
> > data/measurements.
> > I use/employ a 43' vertical on 160 through 17 but can't compare it to a
> > 1/4
> > wave over the same radial field -- certainly your closeness to the
water
> > may "answer" or provide a reason for your success with a 5/8 over 1/4
so,
> > with the modeling info I supplied perhaps someone who knows the modeling
> > apps(s) could do some "investigating" in the form of modeling to answer
> > that?!?~!
> > OK?? 72, Jim R. K9JWV
> >
> >> From: armstrmj@aol.com
> >> Date: Sun, 8 Sep 2013 07:18:18 -0700
> >> To: w8ji@w8ji.com
> >> CC: topband@contesting.com; rodenkirch_llc@msn.com
> >> Subject: Re: Topband: 5/8 wavelength vertical is mo betta than shorter
> > versions??
> >>
> >> Tom (and James),
> >> I am well aware that my comments concerning the 5/8ths wave was based
> >> upon
> > subjective/anecdotal evidence. I am in a science (Astrophysics) by
> > profession..... I do know the difference. HOWEVER, I cannot completely
> > throw out the simple fact that when I altered my 20 meter omni antenna
for
> > Winlink to the 5/8ths, that I received UNSOLICITED comments from the
> > system
> > users stating (100 percent of them) that my signal was much improved
into
> > the areas they happened to be sailing. None of those people, not a
single
> > one, knew that I was changing my antenna. The purpose being just
> > that.....
> > to see if anyone complained or said anything else concerning performance
> > from THEIR point of view. In reality, THAT is the point when supplying
a
> > service..... What do the USERS think of the performance, not what I
think
> > or
> > what a FS meter says.
> >>
> >> Even if I had the equipment to measure the performance and the
equipment
> > says that my signal should be improved, but the Winlink user comes
online
> > and universally states my signal sucks, I will REMOVE that antenna. I
> > know
> > that isn't likely, but if the modelling software states the signals
should
> > be worse and they are, 100 percent, reported as improved, then there is
> > something at play that the modelling software isn't taking into
> > account........
> >>
> >> Not arguing, just answering that initial question that from my
EXPERIENCE
> > with that antenna, it works better than the quarter wave at the same
> > locations I happen to be...... AND ONLY ON 20 meters. I won't speak to
> > any
> > other band, although I would think it would work there, too, because I
> > have
> > not put one up for those other bands.
> >>
> >> As an aside, alot of folks are using that so-called non-resonant
vertical
> > antenna that is roughly 43 feet tall....... They seem to be having some
> > success with them on the bands. Physically, they are pretty
> > convenient.....
> > and on 20 meters, they happen to perform pretty well, judging from user
> > comments, anyway..... and at that band, it is roughly 5/8 wave in
> > electrical
> > height. So, again, I find it interesting that actual experience argues
> > with
> > the modelling software (in MY particular instance). But, again, in my
> > case
> > IN HAWAII, I had an outstanding location that, for some reason I don't
> > know,
> > happened to favor the 5/8 by alot more than even the theoretical gain
> > would
> > indicate. NOBODY would comment, much less 100 percent of commentors, on
a
> > slight gain of 2 db. Heck, that wouldn't be worth the effort. However,
I
> > think you are quite right, Tom..... something else is at play.... ground
> > clutter (I had some.... loads of tropical trees and plants in the area),
> > some significa
> > nt
> >> ly tall sailboat masts RIGHT ACROSS THE STREET from my house (very
> > close), etc, etc. Then you consider the seawater ground that was so
close
> > by...... There are many factors to take into account, not much of which
> > does
> > a modelling software take into account. Undoubtedly the answer is there
> > and
> > not directly related to antenna gain. I did try elevating it on top of
a
> > 40
> > foot pipe mast and using 8 resonant radials....... it made no difference
> > except to increase the chances that high winds would knock it down. In
> > terms of SUBJECTIVE performance and comments, no difference. So, I put
it
> > back on the ground and carried on.
> >>
> >> Remembering what the antenna was for, and where it was located, putting
> >> up
> > a horizontal 80 or 90 feet in height simply wasn't possible. The SERVICE
I
> > was providing required OMNI directional capability, so even a dipole
would
> > be unsat in at least 2 directions...... those being the directions an
> > emergency call would not be heard...... Not a good situation for the
given
> > purpose, right?
> >>
> >> I will say that I didn't appreciate the comment concerning how I came
to
> > my conclusions about antenna performance. Insults only prove that one
has
> > run out of reasonable arguments..... and that is ALL it proves. Given
> > that,
> > this will be my last post here and I am likely removing myself from the
> > list. Insults are NEVER science...... not now, not ever!
> >>
> >> Mike AB7ZU
> >>
> >> Kuhi no ka lima, hele no ka maka
> >>
> >> On Sep 7, 2013, at 18:59, "Tom W8JI" <w8ji@w8ji.com> wrote:
> >>
> >> >> The above modeling results just don't support that contention/posit
so
> > I'm wondering what else comes in to play that could lead folks to love
the
> > 5/8 wavelength vertical over a shorter version, regardless of frequency?
> > I
> > don't see one performance comparison that supports that claim. I'm not
> > saying the "claiming person" isn't correct but....I don't see how!
> >> >> Help - what am I missing here?
> >> >> 72, Jim Rodenkirch K9JWV
> >> >
> >> > The 5/8th wave obtains the small amount of gain it has through
effects
> > of ground reflection. The current maximum is elevated, and that
elevation
> > causes additional phase shift with the illumination of earth out some
> > distance from the antenna. The re-radiation of earth is sometimes
> > explained
> > by an "image antenna". The image antenna is a fictitious antenna
directly
> > below the real antenna, and this "image antenna" simply represents what
> > the
> > earth at a distance does from the illumination from the main antenna.
> >> >
> >> > The 5/8th wave moves the current maximum slightly higher than a
quarter
> > wave above earth, so the fictitious image moves slightly lower than a
1/4
> > wave below surface.
> >> >
> >> > If you move the 5/8th wave above earth, such as in a groundplane well
> > above the earth, the extra length no longer provides gain. Instead, it
> > actually reduces gain at low angles.
> >> >
> >> > Another effect is the extra height above ground of the high current
> >> > area
> > can help get the antenna's main radiating area a little bit higher above
> > ground clutter.
> >> >
> >> > This would also apply to an extended double zepp, where the second
> > antenna half makes the image unnecessary. Each half of the double zepp
is
> > the image of the other side, so we don't need earth.
> >> >
> >> > So it is a very specific benefit from the 5/8th wave caused by moving
> > the current height up above a reflecting surface, or in the case of a
> > double
> > zepp moving current away from a second identical element while still
> > having
> > a common center feedpoint.
> >> >
> >> > One of the biggest antenna hoaxes played on people was the 5/8th wave
> >> > CB
> > groundplane antenna. Two meter 5/8th wave groundplanes are the same. The
> > work on the broadcast band to increase groundwave signal because soil is
> > often reasonably low loss on the AM BCB. If the soil out some distance
> > from
> > the antenna is lossy, or if it does not exist, the 5/8th length causes
> > increased low angle loss.
> >> >
> >> > This is why when you look at models, outside of specific cases like
> >> > some
> > cases of low broadcast band use, we have a tough time seeing the gain
> > imagined or claimed. A field strength meter has an equally difficult
time.
> > :)
> >> >
> >> > 73 Tom
> >> > _________________
> >> > Topband Reflector
> >> _________________
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> > Topband Reflector
> >
> >
> > -----
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> >
>
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