The DK7ZB-5-Band-Quad The DK7ZB-3-Band-Quad Oblong+Rhombus The Extended Oblong Delta-Loops

2-Element-DK7ZB-Quad for 3 Bands (10, 12, 15 m)

This is a small version of the central-fed DK7ZB-Quad. For the principles look at the 5-Band-Quad page.

The Quad has one radiator frame, the center of wires 2 and 1 are interrupted and connected with transmission lines, made of 450-Ohm-Wireman cable.

Feeding with 450-Ohm-Wireman at XX, tuning with an symmetrical ATU. On the german pages are descriptions of some ATUs (Z-Match, T-Match, e.g.)

Each band has a separate reflector loop which is self resonant without stubs.

The boom is 2,00 m long.

Lengths of the not insulated 2-mm-wires (Boom 2,00 m)

Element

Circumference 

Side length 

Spreader (one half) 

Radiator-Loop

14,64 m

3,66 m

2,59 m

Reflector-Loop 15m

14,64 m

3,66 m

2,59 m

Reflector-Loop 12m

12,48m

3,12 m

2,20 m

Reflector-Loop 10m

11,20m

2,80m

1,98 m

  Gain and F/B versus Frequency

Frequency (MHz)

Gain in dBd

 F/B in dB

21,0

5,54

7

21,1

5,54

11,5

21,2

5,28

19

21,3

4,89

28

21,4

4,46

15,5

24,9

5,35

22

28,0

5,97

8,5

28,2

5,95

10,5

28,4

5,88

13

28,6

5,79

15,5

28,8

5,69

18

29,0

5,59

19,5
29,5 5,37 17,5

Azimuth patterns (free space)