ANTENTOP- 01- 2015 # 019

Modified Dipole Antenna DL1BA for 40- and 20- meter Bands

At the current node at the short side it is added wire in length (what the antenna is shortened) 30- 50- cm. At this case the adjusting of the antenna would be simple. At the 20- meter band the antenna is tuned by shortening the added wire. At the 40- meter Band the antenna is tuned by shortening of the one short wire after inductor that laid at non modification (that is without added wire) side. Both tuning practically do not influenced to each other. Figure 2 shows the modified antenna.

The MMANA file of the Modified Dipole Antenna DL1BA for 40- and 20- meter Bands may be loaded: http: // www.antentop.org/019/rw4hfn_dipole_019.htm

Simulation the Antenna in MMANA shows that it is possible to tune the antenna for both Bands by playing the lengths of the added wire (part C see Figure 2) and the short wire after inductor (part B at right side antenna shown on Figure 2).

Figure 3 shows SWR of the modified antenna at the 40- meter Band. Figure 4 shows SWR of the modified antenna at the 20- meter Band.

Figure 3 SWR of the Modified DL1BA Antenna at the 40- meter Band

Figure 4 SWR of the Modified DL1BA Antenna at the 20- meter Band

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