Re: Topband: phased inverted V dipoles
Well said, Guy! I should post this alongside W8JI's quotes and ON4UN's charts on http://www.w0btu.com/160_meters.html . :-) 160 is on the vertical polarization side of a dotted line somewhere between > 160 and 80 meters where there is some poorly defined and poorly understood > modal shift, heavily favoring vertical for non-NVIS paths on 160. > 73, Mike www.w0btu.com _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: phased inverted V dipoles
Yeah, I could believe that. On 80 meters I could believe that. N4AF/NY4A had a fixed Northeast 80m 4 element wire vee yagi off two towers and a 220 foot catenary suspended between. Apex of the vee's 100-120 feet. It was a killer antenna. But it was also on the horizontally polarized side of the modal shift. The first year we had that up, K1ZZ operating at A61 later said NY4A on 80 was THE signal from North America. Tuning was cranky and dependent on things we've only understood fully in recent years. Dunno if Howie will ever want a redo done with the improved principles. Lot of work. To replicate that antenna on 160 we would have needed a pair of 250 foot towers spaced 440 feet with a catenary, or probably more practical, four 250 foot towers with yagi spacing across 440 feet. Howie ain't ever gonna put up anything like that out there. Beaufort County, NC is "Hurricane Alley" where all foreign hurricanes have to check in and show their passport. He's been hit or grazed by nine now, counting Matthew. 73, Guy K2AV On Mon, Oct 10, 2016 at 5:27 PM, mrtoburen7 <mrtobur...@gmail.com> wrote: > I don't recall call but the loudest signal I ever heard coming into KC > from the east coast on 80m was a guy running phased dipoles. It was > amazing but you've got to have the space and supports. > > Aa0fo > > > > Sent from my Sprint Samsung Galaxy S7. > > Original message > From: Filipe Lopes <ct1...@gmail.com> > Date: 10/10/16 4:03 PM (GMT-06:00) > To: Guy Olinger K2AV <k2av@gmail.com> > Cc: topband <topband@contesting.com>, Herbert Schoenbohm < > herbert.schoenb...@gmail.com> > Subject: Re: Topband: phased inverted V dipoles > > Hi Guy > > Thanks for your detailed reply. I am building a two-phase vertical for 80 > meters, 1/4wave separated. Untill now I usee 1 single vertical with around > 50 or 60 radials and I have noticed that towards East the dipole works way > better than the Vertical (maybe because towards NA I have a down slope > cliff untill the ocean and towards EU/AS I have about 100m high montain). > > I got several replies dead it's not worth the effort to put the two dipoles > phased, so I guesd I will skip it and try to compare the 2 elem vert with > dipole towards EU/AS > > Thanks to everyone for the suggestions. > > 73s Filipe Lopes CT1ILT aka CR6K > > Sent from my Huawei Mate 8 > > Em 10/10/2016 10:38 p.m., "Guy Olinger K2AV" <k2av@gmail.com> > escreveu: > > > If that were not enough, W8JI famously had a 160 dipole up 270 feet doing > > A/B tests vs. his verticals, this for over a year I think. In the end, he > > heard better signals on the dipole just a handful of times. Most of the > > time the verticals were significantly better. > > > > 160 is on the vertical polarization side of a dotted line somewhere > between > > 160 and 80 meters where there is some poorly defined and poorly > understood > > modal shift, heavily favoring vertical for non-NVIS paths on 160. > > > > For some, an inverted vee is a possibility where other physical > > configurations are just not possible. If that is what you can do, it sure > > beats not being on the band :>) > > > > Phasing two of them will get you 2-3 db over just one of them. But > probably > > the two will get beaten by an *efficient* inverted L over an *efficient* > > counterpoise, because the L will smoke any inverted vee at low angles, > and > > is on the correct side of whatever the modal shift is. > > > > The emphasized "efficient" modifier twice in the last sentence is very > much > > intentional. > > > > On 160 it is very easy to lose energy to induced current in the ground, > or > > miscellaneous dielectric loss. If your reason for choosing an inverted > vee > > is not because of physical site restraints, then it is very likely that > > prior vertical attempts were diminished, possibly severely diminished, by > > losses avoidable with various techniques. > > > > The big loss advantage of an inverted vee is that 1) there is no lossy > > counterpoise and 2) the RF current max is way in the air. There are ways > to > > invoke those advantages with vertically polarized antennas. An inverted L > > out in the clear over an FCP is a good one, but only one over some > several > > vertical alternatives. > > > > 73, Guy K2AV > > > > On Mon, Oct 10, 2016 at 9:25 AM, Herbert Schoenbohm < > > herbert.schoenb...@gmail.com> wrote: > > > > > Probably not worth the effort as any dipoles less than 250 feet high > are > > > serious cloud warmers. > > > > >
Re: Topband: phased inverted V dipoles
Hi Guy Thanks for your detailed reply. I am building a two-phase vertical for 80 meters, 1/4wave separated. Untill now I usee 1 single vertical with around 50 or 60 radials and I have noticed that towards East the dipole works way better than the Vertical (maybe because towards NA I have a down slope cliff untill the ocean and towards EU/AS I have about 100m high montain). I got several replies dead it's not worth the effort to put the two dipoles phased, so I guesd I will skip it and try to compare the 2 elem vert with dipole towards EU/AS Thanks to everyone for the suggestions. 73s Filipe Lopes CT1ILT aka CR6K Sent from my Huawei Mate 8 Em 10/10/2016 10:38 p.m., "Guy Olinger K2AV"escreveu: > If that were not enough, W8JI famously had a 160 dipole up 270 feet doing > A/B tests vs. his verticals, this for over a year I think. In the end, he > heard better signals on the dipole just a handful of times. Most of the > time the verticals were significantly better. > > 160 is on the vertical polarization side of a dotted line somewhere between > 160 and 80 meters where there is some poorly defined and poorly understood > modal shift, heavily favoring vertical for non-NVIS paths on 160. > > For some, an inverted vee is a possibility where other physical > configurations are just not possible. If that is what you can do, it sure > beats not being on the band :>) > > Phasing two of them will get you 2-3 db over just one of them. But probably > the two will get beaten by an *efficient* inverted L over an *efficient* > counterpoise, because the L will smoke any inverted vee at low angles, and > is on the correct side of whatever the modal shift is. > > The emphasized "efficient" modifier twice in the last sentence is very much > intentional. > > On 160 it is very easy to lose energy to induced current in the ground, or > miscellaneous dielectric loss. If your reason for choosing an inverted vee > is not because of physical site restraints, then it is very likely that > prior vertical attempts were diminished, possibly severely diminished, by > losses avoidable with various techniques. > > The big loss advantage of an inverted vee is that 1) there is no lossy > counterpoise and 2) the RF current max is way in the air. There are ways to > invoke those advantages with vertically polarized antennas. An inverted L > out in the clear over an FCP is a good one, but only one over some several > vertical alternatives. > > 73, Guy K2AV > > On Mon, Oct 10, 2016 at 9:25 AM, Herbert Schoenbohm < > herbert.schoenb...@gmail.com> wrote: > > > Probably not worth the effort as any dipoles less than 250 feet high are > > serious cloud warmers. > > > > > > > > On 10/10/2016 9:21 AM, Filipe Lopes wrote: > > > >> Hi guys > >> > >> We are rebuilding our station and I was thinking about putting up 2 > >> dipoles > >> 1/8 wavelength apart. > >> > >> Has anyone ever tried to phase them for example with Christman method? > >> > >> Thanks > >> Filipe Lopes CT1ILT aka CR6K > >> > >> Sent from my Huawei Mate 8 > >> _ > >> Topband Reflector Archives - http://www.contesting.com/_topband > >> > > > > _ > > Topband Reflector Archives - http://www.contesting.com/_topband > > > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: phased inverted V dipoles
If that were not enough, W8JI famously had a 160 dipole up 270 feet doing A/B tests vs. his verticals, this for over a year I think. In the end, he heard better signals on the dipole just a handful of times. Most of the time the verticals were significantly better. 160 is on the vertical polarization side of a dotted line somewhere between 160 and 80 meters where there is some poorly defined and poorly understood modal shift, heavily favoring vertical for non-NVIS paths on 160. For some, an inverted vee is a possibility where other physical configurations are just not possible. If that is what you can do, it sure beats not being on the band :>) Phasing two of them will get you 2-3 db over just one of them. But probably the two will get beaten by an *efficient* inverted L over an *efficient* counterpoise, because the L will smoke any inverted vee at low angles, and is on the correct side of whatever the modal shift is. The emphasized "efficient" modifier twice in the last sentence is very much intentional. On 160 it is very easy to lose energy to induced current in the ground, or miscellaneous dielectric loss. If your reason for choosing an inverted vee is not because of physical site restraints, then it is very likely that prior vertical attempts were diminished, possibly severely diminished, by losses avoidable with various techniques. The big loss advantage of an inverted vee is that 1) there is no lossy counterpoise and 2) the RF current max is way in the air. There are ways to invoke those advantages with vertically polarized antennas. An inverted L out in the clear over an FCP is a good one, but only one over some several vertical alternatives. 73, Guy K2AV On Mon, Oct 10, 2016 at 9:25 AM, Herbert Schoenbohm < herbert.schoenb...@gmail.com> wrote: > Probably not worth the effort as any dipoles less than 250 feet high are > serious cloud warmers. > > > > On 10/10/2016 9:21 AM, Filipe Lopes wrote: > >> Hi guys >> >> We are rebuilding our station and I was thinking about putting up 2 >> dipoles >> 1/8 wavelength apart. >> >> Has anyone ever tried to phase them for example with Christman method? >> >> Thanks >> Filipe Lopes CT1ILT aka CR6K >> >> Sent from my Huawei Mate 8 >> _ >> Topband Reflector Archives - http://www.contesting.com/_topband >> > > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: phased inverted V dipoles
Probably not worth the effort as any dipoles less than 250 feet high are serious cloud warmers. On 10/10/2016 9:21 AM, Filipe Lopes wrote: Hi guys We are rebuilding our station and I was thinking about putting up 2 dipoles 1/8 wavelength apart. Has anyone ever tried to phase them for example with Christman method? Thanks Filipe Lopes CT1ILT aka CR6K Sent from my Huawei Mate 8 _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: phased inverted V dipoles
Hi guys We are rebuilding our station and I was thinking about putting up 2 dipoles 1/8 wavelength apart. Has anyone ever tried to phase them for example with Christman method? Thanks Filipe Lopes CT1ILT aka CR6K Sent from my Huawei Mate 8 _ Topband Reflector Archives - http://www.contesting.com/_topband