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The Antenna is the best amplifier of the high frequency.
DM2ABK / Y21BK - Karl Rothammel
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On this page you can read about the antennas, which "AYAN DX TEAM" used in the expeditions.
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In our first expeditions we used the simple wire antennas, like "Dipol", "Invertsd Vee", which belong to Roman UY7IQ and Anatol UU5JA.
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But the further experiments with antennas compel us to see us another tasks for antennas, which we using at the mountains:
- easy and compact;
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- with resistanse of the cable is 50 Om;
- with vertical polarization of the radiation;
- which working in the high levels of the statics;
- which has not heavy assembly.
We make many experiments with antennas, and decide, that for the beginning our expeditions we will use the "Delta Loop" antennas.
We make the "Delta Loop" antennas for 80m, 40m, 30m and 20m BANDs. We used the wire P274 from field army phone TA-57. The wire has very good mechanical caracteristics, cheap, and one of the main thing, it is not covered with thick ice.
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For feeding of all antennas we using the coax cable with 50 Om resistance. The best characteristics (also mechanical) has RK50 cable. We using the next cables: RK50-7-11, RK50-7-12. Its working as a halfwave repeater (with account the coefficient of the shortcut). We marked every cable, with writing the length, the frequency and it characteristics.
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As the "Delta Loop" antenna with vertical polarization has the input resistance near 100 Om, we must learned to make the balloons, which was working from 1.8 MHz till 28MHz.
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Diameter of the wires are 0.8 - 1.0mm. R input is 50 Om, R output is 100 Om. SWR of the baloon is 1.0 - 1.1 in the rang 1.75 - 58MHz. For checking the parameters of the baloons we used MFJ-269. Balloon's protection from the precipitation provide by the polyethylene box.
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In the first our expeditions we used the towers like telescope. The height is 10,5 meters (23,5 feet), low diameter is 80 mm (near 3 inch), high diameter is 22 mm (near 1 inch).
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Later, we used the adjustment tower. The diameter of the sections is 40 mm (near 1.5 inch), the lenth is 900 mm (2 feet). The max. height is 12 meters (near 26.5 feet).
The most good variant is the adjustment tower from army station R405. The length of the sections is 1650 mm (near 3.3 feet), the diameter is 60 mm (near 2.5 inch), the thickness of the side is 3 mm (near 0.1 inch).
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For fasr lifting and lowering the antennas (for tuning, repair) at the top of the tower we installed the speacial roller.
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In every expedition we use many mobile stations. Thats why the main antennas were the UHF antennas with vertical polarization for 145MHz and 430MHz.
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The gain factor of this antennas is not so big, near 3.5 - 3.7dB. But the mechanical characteristics are very good. This antennas the Radio Emergency Service of Crimea using near 17 years. For all this time it was not one failure in 86 antennas.
But the main antenna, that we using in all our expeditions on 145 MHz is 3 el. collinear antenna. In the transport condition the length of the antenna is 1380 mm (near 3 feet), in the working condition the length of the antenna is 4016 mm (near 9 feet).
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