ANTENTOP- 01- 2018 # 022

OK3TDC Antenna

OK3TDC Antenna

OK3TDC DX antenna for 80- meter band was widely known in the former USSR. The antenna was published in Amaterske Radio magazine (former Chechoslovakia Republic, Reference 1). Figure 1 shows design of the antenna. The antenna is a loop of 40- meter wire

(lambda/2 for the 80- meter band) installed on a wooden mast in height of near 15 meters. The antenna is fed by 75- Ohm coaxial cable through a delta matching loop that is shown on the Figure 1 at the bottom of the antenna. Antenna has SWR not more then 1.5:1 at all 80- meter band. I did not found strictly sizes for the delta matching loop. Antenna required several lambda/4 counterpoises

UA3GFR used the antenna for the 20- meter band. Figure 2 shows design of the antenna (Reference 2). The antenna was fed through 50- Ohm coaxial cable Matching of the antenna with the cable was made by changing length of the antenna wire and shape of the antenna.

In both cases, for 80 and for 20- meter band, the two antennas have showed excellent performance.

References:

1. Vladimir  Dancik DX antena pre 3,5 MHz.- Amaterske Radio, № 5, 1977, pp.: 194- 195.

2. Radio- Dizain # 24, p.: 83- 84.

Figure 2

OK3TDC Antenna for 14- MHz Band

73! de VA3ZNW

Figure 1

OK3TDC Antenna for 80- meter Band

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