Re: Topband: Vertical Dipoles on 160 Meters
We use the K2KQ inspired vertical dipole at PJ4K for 160. Top's at about 135 feet and bottom at 30 feet. We opted for this approach so that there's no fighting the cactus to install ground-mounted radials. If we can ever get back to the island, we have all the pieces ready to put up a phased pair of these antennas. If you decide to go with this antenna, make sure you consider effects of the vertical supports. We ended up de-tuning our 140-foot towers. 73 charlie, k1xx On 5/7/2021 1:31 PM, John Crovelli wrote: For those who have limited space and are unable to lay out an effective ground system, the vertical dipole offers a very worthwhile alternative to an Inverted-L or low Inverted-V. It is relatively easy to build, install, and tune. The K2KQ article has been followed by hundreds with success. Vertical dipoles on 160 meters have been in place at P40W and P40L for a decade or more. Small footprint, vertical polarization and no ground system were the design parameters that prevailed. 73, John W2GD/P40W/P44W _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Vertical Dipoles on 160 Meters
On 5/7/2021 10:31 AM, John Crovelli wrote: For those who have limited space and are unable to lay out an effective ground system, the vertical dipole offers a very worthwhile alternative to an Inverted-L or low Inverted-V. I think of this as essentially an inverted-L with one elevated radial ... driven at the second harmonic. It seems to me it would work work better with 2 or 4 radials, and with 2 or 4 top loading wires. And it can be driven with a common mode choke at the bottom of the vertical section. Rick N6RK _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Vertical Dipoles on 160 Meters
On 5/7/2021 10:31 AM, John Crovelli wrote: For those who have limited space and are unable to lay out an effective ground system, the vertical dipole offers a very worthwhile alternative to an Inverted-L or low Inverted-V. Yes, and so is the end-loading technique shown in the K2KQ design. N6BT has used it extensively in his designs, and W6GJB and I have used it for portable designs for county expeditions and Field Day. The Hy-Gain AV-series and Cushcraft R-series antennas are loaded and trapped vertical dipoles. VK4YB's 630m end-fed, end-loaded designs for 630m are an even more innovative design -- I helped W6GJB tailor one of those designs to his real estate, and Glen has worked Roger on that band. See VK4YB's qrz page. The key to these designs is realizing that it's current that does the radiating, and maximizing the current in vertical section of the antenna. I do this in NEC by studying the display of current in the View Antenna window. 73, Jim K9YC It is relatively easy to build, install, and tune. The K2KQ article has been followed by hundreds with success. _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: Vertical Dipoles on 160 Meters
For those who have limited space and are unable to lay out an effective ground system, the vertical dipole offers a very worthwhile alternative to an Inverted-L or low Inverted-V. It is relatively easy to build, install, and tune. The K2KQ article has been followed by hundreds with success. Vertical dipoles on 160 meters have been in place at P40W and P40L for a decade or more. Small footprint, vertical polarization and no ground system were the design parameters that prevailed. 73, John W2GD/P40W/P44W _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
