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4B150W End-Fed HF Antenna 7-14-21-28MHz With Joint Waterproof Function For Radio Communications
Why use a long antenna?
(1) Antenna erection is not easy in cities. This antenna is very simple to put up.
(2) It has a slight gain, and has a better effect than a dipole antenna in its larger radiation direction.
(3) The directivity at close range is not obvious.
(4) The need for mobile emergency communications, quick putting up is needed.
Attention:
The advantages of long-line antennas are simple structure, low price and moderate gain. Compared with Yagi antennas and anti-polar periodic antennas, the long-line antenna has lower length directivity and gain. Because its gain is related to the line length, users can find the length and angle that are suitable for receiving lines. By comparing signal wavelength, the length of line can be calculated, which is very suitable for long-distance communications. When the line length is 4 times the wavelength and the elevation angle is 25 degrees, the gain is 3dB higher than the dipole antenna. When the line length is 8 times the wavelength, the gain is 6dB higher and the elevation angle drops to 18 degrees.
Specifications:
- Antenna model: 4B150w
- Features: Thanks to natural resonance, no antenna tuner is needed, with joint waterproof function
- Antenna configuration: 1 x end-fed balun, 1 x storage bag, 2.5 square oscillator 20 meters, 20 meters outdoor drawstring. The feeder is not included and must be purchased separately.
- Input power: Transmit in 30 seconds, receive in 30 seconds, below 150W in SSB, CW mode, below 100W in FT8 mode, below 70W in AM, FM, SFK mode, the following figure 67.9 degrees is a long-term use measurement, when the transmitted is greater than the receiving time ratio, the transmit power must be appropriately reduced.
4B150PLUS End-Fed Balun:
- Frequency range: 3-30mhz
- Withstand power: SSB, CW＜150W; FM, AM, FSK ＜70W
- To ensure the waterproof function of the connector, the vertical tilt angle should be less than 20 degrees during installation
Package Included:
- 1 x Set of End-Fed Antenna
Note: Other items pictured are not included, for demonstration purposes only.
Putting Up The Antenna:
The requirements for the erection of end-fed antenna are very low. It can work normally if it is more than 2 meters away from the ground. To achieve a desired effect, the antenna should be erected in a high and open place as much as possible. When the antenna is erected vertically, because of the low elevation angle, the communication distance is far, it is equivalent to an omnidirectional antenna now. When installed horizontally, due to the high elevation angle of the antenna, the communication distance is relatively short, and it also has a certain directivity. Refer to the figure below for specific erection methods.
