Tropical Band DXing - Part 3

In this next post we will look at a basic wire antenna that will bring in the DX. Knowing how to construct and position your own antennas will go a long way to helping you fill your log with DX as well as making antenna construction fun.

We will refer to the various wavebands by their wavelength rather than their frequency so here is a table you can refer to.

2300-2500 kHz = 120 meter band
3200-3400 kHz = 90 meter band
4750-5060 kHz = 60 meter band

Quarter wave antennas
Without going into the theory of antennas, if we make use of the ground as part of our installation, we need around a hundred foot of wire to receive signals on the 120 meter band.

This length decreases as the frequency rises (and the wavelength falls) and a length of 70 foot or so will give us good reception on the 90 meter band. (It will also give reasonable reception on both the 60 and 120 meter bands.)

If your interest is, say, 120 meters rather than the other two then 100 foot is better. If you want 60 meters in preference to 90 or 120 then around 50 foot is best.

If you want all three equally then you have to except the compromise and go for 70 foot and this is what we will do.

70 foot long wire
We are using the well tried combination of a vertical section followed by a horizontal one. Obviously, every installation will be different and depend on what supports and land are available but, as you will see later, the higher the antenna the better.

Note that the signal is taken from the end of the antenna by coax cable into the shack. Doing this instead of taking the wire directly to the receiver will considerably lessen the risk of picking up noise on the way.

For this antenna you can use whatever wire is to hand. Obviously, proper antenna wire is best but simple bell flex or hook up wire is a close second.

You need to think of stability and durability when you erect antennas so try to look for strong, stable supports that will not sway and snap the wire in the wind. Trees are very useful, if available, or you can use a building or a proper mast.

Once again, money and time spend here will repay itself in producing good, usable signal at the receiver.