PK's Loop Antennas C-DIPOLE-40m User manual

PK's Loop Antennas ABN 76 271 051 082
Clear & Long Range Radio Reception Everywhere
Copyright © 2000 PK’s Loop Antennas
www.a radioantennas.co
Installing your 40m Dipole Antenna
Your new PK’s HF Dipole Antenna is pre-tuned to the middle of the 40m Ham and at 7.1 MHz,
no tuning or cutting is required. The balun should connect to your radio via a suitable length
of coax cable; with this in mind consider antenna height and coax cable length as the
deciding factors for installation. We can supply coaxial cables of various lengths, pre-fitted
with PL-259 connectors. e sure to support the balun by the centre eyelet, to relieve the
weight of the coaxial cable on the dipole wires.
asic T Dipole Antenna
Find a centre support point and two convenient mounting points for the wire ends like; nearby
trees, a fence post, the side of a building or put up some poles.
For DX ( Long Distance) communications, your 40m Dipole will work best at heights greater
than 8m and as far away from buildings and power lines as possible; otherwise interference
on reception and reduced DX range will occur.
If you intend operating the dipole in the N.V.I.S. ( Near Vertical Incidence Skywave ) mode for
Short Distance communications, then consider a maximum height of 3 to 4 metres, with the
dipole flat to the ground, doing this will cause the antenna resonant point to lower, so some
coiling up ( folding back) of the ends of the wires maybe required to resonate the antenna
back to band centre..
The next and most popular dipole and simplest installation method is the Inverted-V
configuration<

PK's Loop Antennas ABN 76 271 051 082
Clear & Long Range Radio Reception Everywhere
Copyright © 2000 PK’s Loop Antennas
www.a radioantennas.co
The Inverted - V
If you choose to use the Inverted-V configuration, you will need to support the dipole by the
centre eyelet at least 8 metres off the ground and angle the wire ends down 70-120 degrees
and fix them using rope to convenient anchor points, like a fence, tree etc. Minor wire
trimming/folding back may be required to tune the antenna on the desired frequency.
Introduction
As you can see from the diagram below, this
antenna gets it
s name from the shape. It's really
just a dipole with the centre raised on a mast and the endpoints near ground. y raising the
centre point, the horizontal space requirement is reduced and only one tall support is
required. Although not the same performance as a dipole at the recommended height of 1/2
wavelength above ground, it is still very effective when space is a premium.
A standard dipole generates a horizontal
radiation pattern in the shape of a figure 8,
with maximum radiation broadside to the
antenna. The Inverted-Vee tends to be more
omni-directional and radiates equally in all
directions.
For best results with this type of antenna, the
Apex Angle should be kept between 70 and
110 Degrees. elow 70 Degrees the radiators
start to become parallel to each other and
signal cancelling will start to occur. Above
110 Degrees the antenna starts looking like a
standard dipole, minimizing any of the feed
impedance and shortening effects. The
optimum Apex Angle is 90 Degrees.
Good DX !
PK’s Loop Antennas
6 lossom Walk, Croydon South VIC 3136, Australia
Email: pkloop[email protected]