Correction, 100X the loss. The deal difference between a single ground rod and a BC station ground will be about 6 dB.
Dave WX7G On Dec 12, 2012 1:13 PM, "DAVID CUTHBERT" <telegraph...@gmail.com> wrote: > 20 dB implies that the ground system loss is 10X the inverted-L radiation > resistance. > > This would result in an input resistance of 250 ohms and a minimum VSWR if > 5:1. > > I don't think that is what the real deal will deliver, do you? > > Dave WX7G > On Dec 12, 2012 12:54 PM, "Guy Olinger K2AV" <olin...@bellsouth.net> > wrote: > >> With the following caveat: The very sparse and short buried radial >> systems >> he is showing are FAR more lossy in practice than shown in his gain >> tables. >> Four twenty foot buried radials beneath a 1/4 wave L on 160, could place >> you down 20 dB. You really can't do that as your 160 meter counter poise >> and expect decent results. You can end feed the same wire on 80/40/30 >> meters (full wave worth of wire in the L on 80m) with four buried 20 foot >> radials and it will be an excellent antenna. This is due to the high Z >> feed at the ground with current max AWAY from the feed point. >> >> A quarter wave L on 160 MUST deal with the counterpoise loss issues, one >> way or another. >> >> 73, Guy >> >> On Wed, Dec 12, 2012 at 2:07 PM, Ashton Lee <ashton.r....@hotmail.com >> >wrote: >> >> > This wonderful article written by L.B.Cebic W4RNL sure can make you a >> > believer in a simple wire inverted L. It is the last antenna discussed. >> > http://www.users.on.net/~bcr/files/backyard%20wire%20antennaes.pdf >> > >> > A $3 wire pulled up into a tree will beat just about any commercial >> > antenna… because it is longer. So on low bands it has increased band >> width >> > and efficiency, and on higher bands it has gain. Yes, I know , some of >> that >> > high band gain is horizontally polarized, but that's not all bad. Just >> get >> > the vertical portion 33 feet or so and you'll be happy as Larry. The >> > article shows that an extensive radial field may not be necessary. >> > >> > And a wire is a lot less visible than a big hunk of aluminum. Without >> > trees, just top load a 43 foot (or possibly even shorter) vertical. The >> top >> > loading could be a T just as easily as an L. People can argue that one >> all >> > day. >> > >> > >> > >> > >> > On Dec 12, 2012, at 11:30 AM, k6xt <k...@arrl.net> wrote: >> > >> > > My first antenna, still in use, on moving to CO is a GAP Titan, >> > advertised to load up 80 thru 10 including WARC bands. The Titan is a >> bit >> > shorter than Voyager, 28 feet or something like it. The advertising is >> > correct, it loads up 180 thru 10. >> > > >> > > But wait. Is it effective on all those bands? No. >> > > >> > > On 80 its a dummy load. On 40 it works extremely well after I added a >> > one foot extension to the bottom wire that encircles the antenna. In >> some >> > cases it is the equal of my shorty HyGain 40 at 70 ft - which probably >> says >> > more about the HyGain than the GAP. For the rest its better on the >> > traditional bands than the WARC bands. It worked a lot of DX for me for >> the >> > couple years it was my only antenna. >> > > >> > > Carrying my experience to the few feet taller Voyager, and from what >> > I've been told by Voyager users, the ant will meet its spec which is to >> > load up on the low bands. Expectation wise I'd expect it to be like the >> > Titan. It loads up but is otherwise a dummy load. Maybe with a batch of >> > radials it could be made to work as well as any other extremely short >> > vertical or GP. >> > > >> > > Not to say there's anything wrong with GAP. My brother had up an R7 >> > which he rated about like the GAP on bands both cover. Those multiband >> > halfwave short verticals work but you get what you pay for. >> > > >> > > 73 Art K6XT~~ >> > > Success is going from failure to failure without a loss of enthusiasm. >> > > ARRL, GMCC, CW OPS, NAQCC >> > > ARRL TA >> > > >> > > On 12/12/2012 10:00 AM, topband-requ...@contesting.com wrote: >> > >> With the prospect of downsizing and moving into senior housing in the >> > future >> > >> I am starting to look at vertical antennas that will allow me to >> > continue >> > >> this wonderful hobby.? I have heard "some" good things about the GAP >> > series >> > >> of antennas but the company says they do not need radials on most of >> > them >> > >> and that worries me.? Over the years I have become very skeptical >> about >> > >> claims and the other BS put out by most companies ( maybe it is a >> > function >> > >> of age I dunno) so I wonder if these antennas really work.? The two >> > antennas >> > >> that I am interested are the Voyager DX for 160/80/40? and the Eagle >> DX >> > for >> > >> the rest of the bands. >> > >> >> > >> So my question is.... does anyone have actual experience with these >> > antennas >> > >> (especially the voyager) as compared to other antennas for a specific >> > >> frequency.? Now guys .. I know you cant really compare a 6 element >> beam >> > to a >> > >> vertical of this kind but I am talking about a comparison that is >> > >> realistic.. like how does it hear, tune, match & get out compared to >> > >> something like another vertical or a dipole up some reasonable >> distance. >> > >> >> > >> I sure hope this has not opend another can of worms.. some how I seem >> > to do >> > >> that .. private emails are ok..especially it the topic gets out of >> hand >> > and >> > >> we get a large volume of comments (Tree please dont shoot me before >> > >> Christmas my wife will miss me.) >> > > >> > > _______________________________________________ >> > > Topband reflector - topband@contesting.com >> > > >> > >> > _______________________________________________ >> > Topband reflector - topband@contesting.com >> > >> _______________________________________________ >> Topband reflector - topband@contesting.com >> > _______________________________________________ Topband reflector - topband@contesting.com