Figure
19 shows a SWR at 50- Ohm coaxial connected through matching
device (see Figure 14) to 'wide' antenna (see Figure 12).
SWR was simulated by MMANA. Theoretical gain for the antennas
is near 1,1- 1,3 dBi
A 'narrow antenna with capacitive loads of up or down
installation has theoretical pass band 157 kHz at SWR 1,5:1 at 50- Ohm coaxial cable, and pass band 314 kHz at SWR
2:1 at 50- Ohm coaxial cable. A 'wide' antenna has theoretical
pass band 425 kHz at SWR 1,5:1 at 50-
Ohm coaxial cable, and pass band 733 kHz at SWR 2:1 at 50- Ohm
coaxial cable.
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So those antennas
can work only at a part of the 10 meters band. For working at
all 10- meters band matching device can be retuned for needed
frequency. However, the 'wide' antenna often works at all 10 meters
band without retuning the matching device due losses at neighbor
subjects.
References:
1. Igor Grigorov. Antennas. Matching and Adjustment.-
Moscow.
RadioSoft, 2002. ISBN
5-93037- 087-7
2. http://dl2kq.de/
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