Do J pole antennas have gain?
Primarily a dipole, the J-pole antenna exhibits a mostly omnidirectional pattern in the horizontal (H) plane with an average free-space gain near 2.2 dBi (0.1 dBd).
What does dBi stand for antenna?
decibels relative to isotropic
The expression dBi is used to define the gain of an antenna system relative to an isotropic radiator at radio frequencies . The symbol is an abbreviation for “decibels relative to isotropic.” The dBi specification is based on the decibel , a logarithm ic measure of relative power .
Does a VHF antenna need to be vertical?
Antenna placement: Your VHF antenna attached to the AIS device needs to be as high as possible and as far away as possible from other vertical metal objects. Vertical metal objects include other vertical antennas, sailboat masts, radar masts, stays, bimini frames and any other lengths of metal parallel to the antenna.
What kind of antenna do you need for a J pole?
The Copper Cactus J pole antenna design is a simple amateur radio antenna model that will allow you to operate both bands with good performance, it is easy to make and the web offer several projects and examples we have collected here below for your reference. The Copper cactus antenna Copper Cactus multiband J-Pole antenna (by info)
Is the 2 meter antenna a dual band antenna?
Dual Band Performance in a single antenna: Each antenna is individually tested and tuned for optimum performance on their respective bands. The two meter antenna is tuned to 146MHZ (1.2:1 SWR or less at 146MHz), and the SWR is 1.4:1 or less throughout the entire 2 meter band. This antenna also works great as a dual band antenna.
How long does it take to build a 2 meter copper antenna?
Easy home brew 2 meter copper jpole antenna build – under 20 bucks – Hits repeaters 45 miles away. Parts used bought at home depot build time 1 hour. (by K0BET) Homebrew a j-pole 2mt and 70 cm antenna project.
What should the SWR be on a 2 meter antenna?
Each antenna is individually tested and tuned for optimum performance on their respective bands. The two meter antenna is tuned to 146MHZ ( 1.2:1 SWR or less at 146MHz ), and the SWR is 1.4:1 or less throughout the entire 2 meter band. This antenna also works great as a dual band antenna.