I thought I said that....... Oh wait I DID say that ! AND, A VEE will have a slightly more omni-directional pattern. (That's where the gain of the horizontal dipole went !)
73, Charlie k3ICH -----Original Message----- From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> On Behalf Of Bob McGraw K4TAX Sent: Friday, December 07, 2018 9:18 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] Less Than Perfect Antennas [was Flumoxed] While I agree with Jim's information, I would point out the flat dipole will have 3 dB more signal off of its broadside 0/180° as compared to that of a inverted V dipole off of its broadside. At the same time, the inverted V dipole will have about 4.5 db more signal off of its ends 90/270° as compared to that of a flat dipole off of its ends. It appears what one loses with one antenna is made up with the other antenna depending on azimuth and apex angle of the inverted V being somewhat greater than 90°. In fact it appears that the Inverted V has almost an omnidirectional pattern at an elevation angle of 25°. Fig 9.6 If a close match to 50 ohms is required, it is best to adjust the angle for lowest SWR while maintaining resonance by adjustment of the length. Reference: ARRL Antenna Book, 22nd Edition, 9.1.3 Inverted-V Dipole 73 Bob, K4TAX On 12/7/2018 6:51 PM, Jim Brown wrote: > On 12/7/2018 12:55 PM, Dick Dickinson wrote: >> Why is there so much promotion of dipole antennas over inverted vee >> type antennas? > > As has been noted, an inverted vee is a compromise dipole -- the sort > of thing you can rig with a single support. A flat dipole with its > center at the same height as the inv vee will have a dB or two more > gain, and the directional pattern will be the classic "figure-eight" > pattern with broad peaks broadside to the wire and nulls off the ends. > Inverted vees tend to lose the nulls off their ends. All this stuff is > in the ARRL Handbook and Antenna Book which every ham should own and > study as we have time. > > For rigging heights that are possible for most hams, horizontal > antennas for 160 or 80, and 40M over flat terrain produce more gain at > greater height. It is a fallacy that an antenna must be low to work > short distances. Low antennas radiate LESS signal at high angles than > high ones. I published a study of this several years ago. It's here. > http://k9yc.com/AntennaPlanning.pdf beginning on page 10. Field > strength at 70 degrees vertical elevation just starts to fall off as > it is raised to 1/3 wavelength. That's 45 ft on 40M, 90 ft on 80M, 180 > ft on 160M. > > 73, Jim K9YC > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html Message delivered to > rmcg...@blomand.net ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to pin...@erols.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
