4B150W End-feed Short Wave Antenna 4 Bands 7/14/21/28MHz Simultaneous Resonance Waterproof Connector

4B150W End-feed Short Wave Antenna 4 Bands 7/14/21/28MHz Simultaneous Resonance Waterproof Connector

Specification:
Size: 25 x 15 x 13cm
Antenna model: 4B150w, natural resonance without day adjustment, with connector waterproof function

Description:
The advantages of long-line antennas are simple structure, low price and moderate gain. Compared with the Yagi antenna and the counter-periodic antenna, the long-line antenna has low directionality and low gain. But the advantage is that because its gain is related to the length of the line, the user can find the length and angle of the best receiving line. By comparing the signal wavelengths, the length of the line is calculated, very suitable for long-distance communication. When the line length is 4 times and the wavelength is 25 degrees, it 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 is lowered to 18 degrees.

Input Power:
Transmit in 30 seconds, receive in 30 seconds, ssb, cw mode below 150W, FT8 mode below 100w, below 70W in AM.FM, SFK mode. When the transmission is greater than the receiving time ratio, the transmission power must be appropriately reduced.

Antenna Installation:
End-feed antenna installation requirements are very low, it is required to work more than 2 meters away from the ground, but to achieve the desired effect, it should be as high as possible and as far as possible. When the antenna is less than 2 meters away from the ground or close to other objects, the resonance point will be slightly higher. When the antenna is erected vertically, it is connected far away because of the low elevation angle, which is equivalent to an omnidirectional antenna. When it is erected horizontally, it is relatively close to the connection because of the high elevation angle, and it also has a certain directionality.

Antenna Adjustment:
Because the feeder and the installation environment may affect the resonance point, the antenna vibrator is equipped with an adjustable resonance point device. When you install the antenna, please perform a standing wave (resonance point) test, with 7M as the benchmark, it should be at 7.07Mhz resonance point ( namely the lowest standing wave frequency point). This antenna uses the principle that the 4 bands are multiples to realize the principle that one vibrator resonates at four frequency points at the same time, so the resonance points of its four bands are linked; assuming that the resonance point is 7.07M, then the other bands are about 14.270, 21.400, 29Mhz. Or according to the frequency point you use to adjust the length of the vibrator to obtain. (no need to trim, just change the length of the vibrator)

Package List:
-1 x 64:1 End-feed Balun
-1 x Storage Bag
-1 x 2.5 Square 20m Vibrator
-1 x 20m Rope