Topband: 5/8 wavelength vertical is mo betta than shorterversions??

[James Rodenkirch]

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 at nc.rr.com
> To: km1h at jeremy.mv.com; rodenkirch_llc at msn.com; armstrmj at aol.com; w8ji at w8ji.com; tshoppa at wmata.com; w7dra at juno.com
> CC: topband at 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 at jeremy.mv.com] 
> Sent: Sunday, September 08, 2013 12:24 PM
> To: Charlie Cunningham; 'James Rodenkirch'; 'Mike Armstrong'; 'Tom W8JI';
> Shoppa, Tim; w7dra at juno.com
> Cc: topband at 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 at contesting.com] On Behalf Of James
> > Rodenkirch
> > Sent: Sunday, September 08, 2013 11:00 AM
> > To: Mike Armstrong; Tom W8JI
> > Cc: topband at 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 at aol.com
> >> Date: Sun, 8 Sep 2013 07:18:18 -0700
> >> To: w8ji at w8ji.com
> >> CC: topband at contesting.com; rodenkirch_llc at 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 at 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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