Measurement results for the 2-element DK7ZB Yagi on 20m

Podľa

20. August, 2026

The antenna analyzer was supposed to provide information on some of the characteristics of the DK7ZB Yagi on 20m. Since a duralumin boom was not available, I used a longer iron rod for testing. Attaching the elements to the boom is simple. A small duralumin mast, 4.5 m tall, was set up. Positioning the antenna even at this height was complicated by the weight of the boom and the many cables in the garden—telephone lines, a 5-band dipole, a concrete-encased mast, and a garden shed.

First, I rotated the antenna so that it was as far away from the house as possible. The reflector crossed a telephone cable. The antenna analyzer showed resonance below the band. I rotated the antenna by about 50 degrees, and here are the measurement results for the 2-element DK7ZB Yagi for 20 m at a height of 4.5 m:

Frequency	Impedance	PSV
13.85 MHz	94 + j0 ohms	1.89
13.90 MHz	87 + j0 ohms	1.74
13.95 MHz	77 + j0 ohm	1.56
14.00 MHz	66 + j0 ohms	1.33
14.05 MHz	63 + j0 ohms	1.26
14.10 MHz	57 + j0 ohm	1.15
14.15 MHz	52 + j0 ohm	1.05
14.20 MHz	50 + j0 ohms	1.00
14.25 MHz	48 + j0 ohm	1.03
14.30 MHz	46 + j0 ohms	1.06
14.35 MHz	45 + j12 ohms	1.32
14.40 MHz	43 + j21 ohm	1.60
14.45 MHz	41 + j26 ohm	1.88
14.50 MHz	40 + j31 ohms	2.06