This antenna originally came from abroad, and the description of this antenna abroad: "It is widely used in military, water conservancy and other emergency communication. The antenna is concealed, easy to erect, does not need to be debugged, and does not require a day adjustment. It can be at 1.5-30mhz. Short-wave full-length work, 0-500 km without blind zone, effective distance and inverted v antenna, effective communication within 1000 km." As early as in 2005, I have done 1 batch for a few radio friends in Shenzhen. It is quite practical and convenient. It is especially suitable for those who are not ideal in urban setting, and who are too small to be able to set up. Friends who can't go up, because it can be erected in the roof, balcony, window sill, field, etc., and can be erected in various forms, horizontal, inverted v, triangle, frame, serpentine, folding, window, etc. Etc., and it is invisible erection (outsiders do not know what this is, think it is the rope to dry clothes, free of complaints). When it is erected outdoors, it is more convenient. You can easily pick up the antenna at a distance of 0.5 meters or more on the roadside. The geographical position can't straighten the antenna. If there is no problem, let the antenna go around 's'. Type can also be done, 1 minute to get the antenna erection! ! It is a good helper for setting up radio stations in special outdoor and setting up radio stations in special environments! ! !
This antenna is very convenient to set up. It can be set up in 1 minute for 1 person, and the antenna does not need to be debugged. The standing wave from 1.5mhz--30mhz is very ideal. There is no strict requirement from the ground. 0.5m above the ground. The above can work.
Recently, many HAM friends, feedback back, HF20A tilted 10 degrees in a frame-type horizontal, the communication effect is very good. Particularly representative is the BG7YB (Hainan Haikou) triangular window obliquely pulled down to the big tree downstairs, which communication effect is comparable to the short wave Yagi, the sound is loud and full, the signal is just, within 1000 km, thunder-like signal! Extraordinary!
2, the selection of the national standard brand of black soft copper wire, better concealment
3, this batch uses a larger and better magnetic ring, so that the parameters are more ideal! Can withstand 200W of high power (when production, it must be tested by 200W high power for a long time).
The biggest change of the new version of HF20A is: the absorption load is made of customized products, the volume is smaller, the appearance is more beautiful, the data is more excellent (from the test chart can be seen better performance).
HF20A is a multi-purpose short-wave full-length single-line traveling wave antenna with high radiation efficiency and convenient installation. It can be used for personal portable stations and temporary base stations in the field. Often used to compensate for the presence of NVIS blind spots in general antennas. When the cable is erected, the 25W~50W portable platform can be used for 0~800km, and the 125W vehicle can be used for 0~1500km. When the flat pull is erected, the directional communication distance is further.
For many years, HF20A antennas have been widely used in military, forest fire prevention, field exploration and construction, adventure tourism and other fields. Due to their low price, good communication effect and convenient use, they are widely welcomed by users.Specification:1. Maximum power: 1000W, average power: 50W2. Working frequency: 0.5-30MHZ, SWR<2.03. Standard vibrator: 20 meters4. Vibrator material: 1-1.5mm multi-strand copper core wire5. Stainless steel ground nail: 2 pieces (self-provided)Actual installation prompt1. The roof is fixed for a long time. It is not necessary to use the ground anchor when installing. Connect the two tail ends of the antenna directly with one wire to connect the two tail ends, or directly connect the two tail ends directly. SWR Ideal, simple and practical. (The basic condition for the operation of this antenna is that the two tails must form an indirect or direct loop to work)2. In actual outdoor use, if the ground anchor is not in good contact, the antenna will not form a loop, and the SWR will be high. You can pour water to the ground anchor to create a good circuit for the earth to lower the SWR. If the ground anchor cannot be used in the rock area, the two tail ends of the antenna can be directly connected and used to form a "triangle" and other variant shapes to work.3. Generally, the height of the antenna will affect his radiation efficiency and distance. Generally, the antenna is a little higher, the angle is larger, the radiation will be better, the distance will be far, the blind zone will be larger, the installation will be lower, or the angle will be smaller. The radiation is almost the same, the communication distance is close, and the blind spot is less.4. The length of the vibrator has little effect on the SWR. In theory, the longer the vibrator, the higher the radiation efficiency.5. When using for long-term fixed use, it is necessary to do anti-rust treatment of the screw. It can be applied with butter to prevent the screw from rusting and waterproof (waterproof inside the antenna part and cause damage)