WebARRL - Home Web2 Meter Antennas 2M/440 MHz Dual Band Copper J-Pole From N7QVC 2M Fan Antenna (Yes From an Electrical fan) 2 M 1/2-Wave J-Pole-- VHF-FM (Stealth) Antenna Made From 450-Ohm Ladder Line -- From KB1GTR & KB1DIG 2M Self Supporting J-Pole for Emergency Use-- From Bob Hejl W2IK 2M Log-Periodic Dipole Array -- From The ARRL …
The J-Pole and Other VHF/UHF Antennas, by Tunnel Rabbit
WebR 2 ≈ 1.24 meters So the minimum separation would be ~2.1 meters. If you wish to play it safer and have each antenna in the other's Fraunhofer zone (far field) then use the formula: (2) R = 2 D 2 λ where D is the maximum linear dimension of the two antennas. WebApr 9, 2024 · Building J-poles and Slim Jim antennas out of 1/2 inch copper pipe, is a good choice as the build is rugged and reliable. It is a practical choice for the novice or experienced antenna builder. And this type of antenna can be used horizontally polarized. One might buy their first j-pole antenna from KB9VBR on Ebay to study how it is … jolene wright lmhca
End-fed Vertical and J-pole
WebJun 17, 2012 · A J-Pole is 2.5 db, so your 50 watts translates to approx 85 watts, or 10 watts to 18. (After the duty cycle calculation, your exposure drops to 42 and 9 watts respectively. The FCC only requires you to make a station evaluation if you are running more than 50 watts on the 2 meter band. WebJun 30, 2024 · The J-Pole is really what I call a medium gain antenna. It’s a half wave antenna by design so it has about 2.5 – 3 dB of gain depending on how you want to calculate things. It doesn’t have a whole lot of gain but really a lot of times you don’t need a whole lot of gain for a good vhf uhf antenna. Purchase 2 meter amateur radio J-Pole ... WebHere is a 70cm (440 Mhz) J-Pole antenna that is inexpensive, and easy to build. Author use 1/2 inch copper pipe, and the associated fittings necessary. The dimensions aren't typical however, this is what it took to get its SWR low. 70cm yagi antennas Pictures and plans to build 70 cm yagi antennas Bazooka dipole for 70 cm band how to import udon sharp