Wireman-J-Poles

The Vertical Sloping Dipole

The CE0Y-7-m-Triple-Leg

Vertical 2x7m-Double-Zepp

The Battle-Creek-Special

The Sloping Vertical Dipole (DK7ZB)

The radiating part is the vertical half of the dipole. You get nearly radiation in all directions, the second half must not be in 180. The table below show how we get an impedance for direct feeding of 50Ohm coax.

Angle a

Impedance

Principle

180

72 Ohm

Vertical Dipole

90

42 Ohm

Sloping vertical Dipole

120

58 Ohm

Sloping vertical Dipole

135

64 Ohm

Sloping vertical Dipole

 

If the feeding point is 10m above ground, we will get a slightly deformation of the elevation diagram.

The angle of the sloping part is here about 120. For example a 15m-antenna, on the other bands the plot is the same.

 

A simple method for erecting the vertical part is the mounting of the wire on a fishing rod. If you use wire with 1mm (not insulated!), the lengths are in the table below. Insulated wire causes a length of 3-4% less. If the vertical part is made of aluminium tubing, we also must shorten this length about -3%.

Lengths for Monoband-Sloping Verticals with 1mm-Wire (not insulated)

Band

10m

12m

15m

17m

14m

30m

Length of one half

2,54m

2,89m

3,40m

3,98m

5,10m

7,14m

Left:

With a trap in each half we have a 2-band-antenna.

l1 for higher band, trap+l2 for lower band.

Right:

It is possible to use one trap in the vertical part and two "radials" for each band in parallel (g1 and g2).

Details of the mounting system with automotive clamps and two pieces of insulated plates.

Because the antenna is a symmetrical system it needs a balun. The best and easiest way is a W1JR-balun-choke.

2x 4 windings of RG-174 on a FT 140-43 can handle 150 Wtts, with RG-58 are 400 Wtts possible. For power up to 1 KW use a FT240-43 with Aircell-5 coax.

The coax socket should be grounded on the supporting mast for lightning protection.

The box before mounting the balun.

The box with the balun

Left:

The portable version of the sloping vertical dipole has a coax choke, 15 windings on a 50mm-PVC-tube. Simple and effective!

Right:

As with the real vertical dipole ist is possible to bend one part to a sloping vertical dipole and feed with 2-wire-open line (Wireman or homemade) and a symmetrical ATU. The radiation patterns are similar to the vertical dipole.

This is a good choice for portable operation from a balcony  with a fishing rod as support for the vertical part.

If you use three "radials" in 120, we get a "Multiband-Triple-Leg", the three "radials" can be used as supporting ropes. 

 

For the impedance transformation special Wireman-lengths are useful for the connection to the ATU:

2,75 m, 4,05 m or 9,00 m

With other lengths you will probably to high impedances which cannot be matched by the Tuner.