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 , 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

Built by

Gunter, DL2DRG

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)

horizontal rule

horizontal rule

horizontal rule

The stacked Version with the 25-Ω-Quadlong

For the stacked version the impedance of the single Quadlong was changed to 25 at XX because with that impedance a clever stacking is possible. With two lengths L of 50--coax 3/4- λ* V (with full-PE 2 x 103,5 cm) we have an impedance transformation to 100 at XX. With both cables parallel we get 50 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.

Lengths (6-mm-elements):

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 144-MHz-DK7ZB-Double-Quadlong

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