What is a Zepp antenna?

The Half-Wave Zepp is an end-fed half-wave antenna. That is, it is a piece of wire one-half wavelength long with the feedline connected at one end. Like a dipole, it might be an odd multiple of half wavelengths: λ/2, 3λ/2, 5λ/2, and so on. Unlike a center-fed dipole, an end-fed antenna has a very high input impedance.

What is a center fed antenna?

The half-wave center-fed dipole is one of the most popular antennas in use today. In free space the center-fed half-wave antenna has an input impedance that is a close match to 50 ohm coax and to most radios that have a 50 ohm output impedance. It can be installed as an inverted V or as a straight dipole.

Does a 80 meter dipole length antenna have to be in straight line?

Dipole antennas need not be installed in a horizontal straight line.

What is double Zepp antenna?

A Double Zepp is a center-fed 1/2 wavelength antenna. The double extended Zepp is a dipole type Antenna consisting of two collinear 0.64 wave length elements fed in phase. This double extended version provides 3 db gain over a dipole on the band it is designed for and each side or leg is about 5/8 wavelength long.

How does an end fed antenna work?

In the case of an end-fed antenna fed with open-line, only one wire at the end of the feed line is connected to the half wave antenna. At the end of the other wire, current still runs into the antenna, otherwise the radiator wouldn’t do anything. So at this point there is imbalance in the feed line.

Does AJ pole antenna need to be grounded?

J-Pole antennas are half wave antennas by design. But instead of an RF ground, the antenna should have an electrical ground to protect it in case of a lightning strike. An electrical ground doesn’t enhance the RF radiation of the antenna, but it is an important safety feature on any installation.

How is dipole antenna length calculator?

Dipole length formula Two versions are given for this length calculation – one using the length in metres and the other for the length in inches. Often a formula for the length of a dipole in feet is seen as 468 / frequency.

How high off the ground should a dipole be?

Recommendation. For best results, dipoles should be at least 1/2 wavelength above ground level. For the lower bands, especially 160-40 meters, this can become impractical–place your dipole as high as your situation allows.

Can a dipole antenna be curved?

One way to fit a dipole antenna in a restricted space is to bend the legs. They can be bent horizontally, drooped downward, or any other imaginable configuration to fit in the space available.

How does a G5RV antenna work?

7 MHz, 40 metres: On 40 metres the G5RV antenna operates using the top section plus nearly 5 metres of the matching section and it operates as a partially folded collinear array with two half waves in phase. Again the antenna presents a reactive load to any transmitter at its input.

Are end fed antennas any good?

End fed wire antennas can work very well under many circumstances. They have some disadvantages, but with careful installation, they can work well and be particularly versatile offering multi-band operation.

How long should an end fed antenna be?

It is important to use a counterpoise. A standard recommendation (see QST, March 1936, p. 32, “An Unorthodox Antenna”) is an 84′ long end fed and a 17′ long counterpoise (6.5′ for 20m)….Wire Lengths for Various Band Combinations.

What does Zepp stand for in a vertical antenna?

End-fed vertical j-pole and horizontal zepp end fed zepp, j-pole, and double zepp antennas Zepp end-fed Antennas Related Pages: End fed longwire or random wire antenna Groundplane Verticals(they are generally end-fed 1/4 wave radiators) Verticals and baluns End-fed half wave J-pole

How is current forced into an end fed antenna?

Because the antenna end-impedance is some finite value, sometimes even lower than we might expect, significant current must be forced into the antenna end. The feed line or stub connection cannot force current up or out into an end-fed antenna without equal current flowing into some form of counterpoise at the feed line or stub connection.

Which is an end-fed half wave groundplane antenna?

Related Pages: End fed longwire or random wire antenna Groundplane Verticals(they are generally end-fed 1/4 wave radiators) Verticals and baluns End-fed half wave J-pole It is important to understand the feed line before discussing end-fed antennas, or antennas like the J-pole or Zepp.

What do you need to know about J-pole antennas?

J-pole It is important to understand the feed line before discussing end-fed antennas, or antennas like the J-pole or Zepp. feed line Balance We often hear a balanced feeder is properly balanced when the feeder has equal currents in each leg.