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: [email protected] > To: [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected] > CC: [email protected] > 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:[email protected]] > Sent: Sunday, September 08, 2013 12:24 PM > To: Charlie Cunningham; 'James Rodenkirch'; 'Mike Armstrong'; 'Tom W8JI'; > Shoppa, Tim; [email protected] > Cc: [email protected] > 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:[email protected]] On Behalf Of James > > Rodenkirch > > Sent: Sunday, September 08, 2013 11:00 AM > > To: Mike Armstrong; Tom W8JI > > Cc: [email protected] > > 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: [email protected] > >> Date: Sun, 8 Sep 2013 07:18:18 -0700 > >> To: [email protected] > >> CC: [email protected]; [email protected] > >> 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" <[email protected]> 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 > >> _________________ > >> Topband Reflector > > > > _________________ > > Topband Reflector > > > > _________________ > > Topband Reflector > > > > > > ----- > > No virus found in this message. > > Checked by AVG - www.avg.com > > Version: 10.0.1432 / Virus Database: 3222/6147 - Release Date: 09/08/13 > > > _________________ Topband Reflector
