What is the impedance of a vertical antenna?
The typical resonant feed point impedance of a 1/2 wavelength antenna (with a reasonable ground system of at least 1 raised radials or 2 radials at ground) is 2,000-4,000 ohms and can be impedance matched with an LC circuit or high ratio impedance matcher such as the Bullet-64 or 64:1 unun which matches 3200 ohms to 50 …
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 is a 5’8 wave antenna?
The 5/8 wave antenna consists of a vertical radiator which is fed at the base of the antenna. A half wave antenna’s radiation peak angle is 20 degrees. You’ll find that the 5/8 wave antenna’s angle of radiation is just 16 degrees making it an even better dx antenna. You may have noticed a pattern developing here.
How many radials do I need for a vertical antenna?
Butternut recommends a minimum of 30-60 radials at 65 feet each. Hy-Gain suggests numbers based on a chart similar to Table 1 below. It’s obvious there isn’t a consensus among vertical antenna makers. If you need a number to start, twenty 32-foot radials will give you a workable system with most vertical antennas.
What is the gain of a vertical antenna?
When used as a vertical radiator against a ground plane this translates to a length of 5/8 wavelength. It is found that a five eighths wavelength vertical antenna has a gain of close to 4 dBd, i.e. 4 dB gain over a dipole.
What is a 5/8 wave antenna used for?
Just a happy few build a 5/8 wave vertical antenna. This is remarkable, since the 5/8 has the lowest angle of radiation and a little bit more gain (depending on ground conditions). Whenever you have an open field to place an HF vertical, you should consider the 5/8 for DX’ing.
What is the difference between a dipole and a 5/8 wave antenna?
The first is GAIN. The computer shows that the antenna (mounted 1 foot above ground) has a gain of about 1.5 dBd higherthan a dipole’s gain (also mounted 1 foot above ground.) The second reason you may want to use the 5/8 wave vertical is to obtain a lower angle of radiation.
What is the best antenna size for a vertical antenna?
Lots of radio amateurs build their own verticals. Most of them tend to stick to vertical antennas with a 1/4 or 1/2 wave sizing. Just a happy few build a 5/8 wave vertical antenna. This is remarkable, since the 5/8 has the lowest angle of radiation and a little bit more gain (depending on ground conditions).
What is the vertical gain of a 5/8 wavelength antenna?
Properly constructed, the 5/8 wavelength vertical will show a gain of slightly more than 3dB over a dipole. Lower angle of radiation. According to some antenna experts, the 5/8 wavelength shows a low vertical angle of 16 degrees to the horizon.