|Theory of the Quadlongs||4/6-m-Quadlongs||2-m-Quadlong||2-m-4x-Quadlong||2-m-4x-Oblong||The Hentenna (2 m, 4m, 6 m)|
The 144-MHz-DK7ZB-Quadlong and Double-Quadlong
New Double-Quadlong see down!
The 2-m-Quadlong was designed for 144,3 MHz to use it for horizontal polarisation in the CW/SSB-modes.
Stacked versions see below!
Short Data of the DK7ZB-Quadlong
Gain 6,5 dBd, F/B 18,5 dB
3-dB-angle hor. = 72°, 3-dB-angle ver. = 70°
Picture right: Scheme of the Quadlong
Impedance 28 Ω , feeding with the DK7ZB-Match
Dimensions for the 144-MHz-Quadlong:
Distance Loop-Reflector = 300mm
All lengths given from center to center!
Lengths in the table below.
2x 28-Ohm-Quadlong stacked
|Diameter Loop rods||Length ver||Length hor||Length Reflector|
|4mm||782 mm||314 mm||1030mm (8mm)|
|5 mm||785 mm||314 mm||1034 mm (5 mm)|
|6 mm||787 mm||314 mm||1033 mm (8 mm)|
|10 mm||797 mm||314 mm||1034 mm (10 mm)|
The stacked Version with the 25-Ω-Quadlong
For the stacked version the impedance of the single Quadlong was changed to 25 Ω at XX because with that impedance a clever stacking is possible. With two lengths L of 50-Ω-coax 3/4- λ* V (with full-PE 2 x 103,5 cm) we have an impedance transformation to 100 Ω at XX. With both cables parallel we get 50 Ω at XX.
The first 45 cm of the cable starting at XX is wound to a coax-choke for balanced feeding of the loop. The distance between the two antennas (parts 3 and 10) is 110 cm. This feeding is described at the 2x25-Ω-Yagis stacked (Lightweight-Yagis).
Gain 9,6 dBd
F/B 21 dB
3-dB-angle hor. = 72,2°
3-dB-angle ver. = 30,0°
The gain is 9,6 dBd with excellent radiation patterns. The 9,83 dBd in the right plots are without the stacking losses.
Hor. (3, 4, 9, 10) = 298 mm
Ver. (1, 2, 7, 8) = 806 mm
Reflectors 1029 mm, 8-mm-Diameter
Distance Ref-Loop 295 mm
The Quadlong can be built up with a double frame. The gain increases only 1 dB, but this antenna has a greater bandwidth than the single Quadlong. Feeding with the DK7ZB-choke, the same as for the Quadlong.
Data of the DK7ZB-Double-Quadlong:
Impedance 28 Ohm
Gain 7,5 dBd F/B 23 dB
3-dB-angles 72° hor 55° ver
The gain is 0,7 dB higher than the well known "Double-Quad" by DL7KM and DJ9HO. The mechanical construction is much easier!
The lengths ot the elements, distance center to center of the tubes
|Ref.-Length||1050 mm (10 mm)|
|D (Ref-Loop)||320 mm|
|3, 4, 6 (hor)||312 mm (10 mm)|
|1, 2, 5, 7 (ver)||725 mm (10 mm)|
New Double-Quadlong with higher gain and 50 Ohm impedance
|With feeding in the
lowest section (not in the middle) and a greater ratio between the
horizontal and vertical parts we get new characteristics:
Impedance 50 Ohm
Gain 7,8 dBd
All tubes 8 x 1 mm Aluminium