6 May 2015

10m antennas

As you will have noticed by now, 10m is one of my favourite bands.  Although quiet at many times in the solar cycle it always comes to life with Es from late April until September. Alert 10m operators will sniff out Es at other times too, but there may be long periods of noise, as on 6m. WSPR is an ideal mode when the band may otherwise seem quiet.  It is good for local nattering at any time and F2 N-S DX  is often there even at solar minima.  Antennas for the band are small and easy to make such as the design on my website for a 10m halo. See https://sites.google.com/site/g3xbmqrp3/ .

A video of K7AGE making a dipole for 10m is available at YouTube.  See https://youtu.be/84F4UgSWmQo.   In this video, Randy is making a dipole for the USA technician's band, so to cover the main SSB band (28.4 to 28.6MHz) you will need to make the wire slightly shorter.  In my experience if you cut the wires for the centre of the band it will still have a pretty low SWR at the band edges. Even a very simple ATU will bring the SWR down to 1:1, although  unless your rig has a problem with a mismatch of around 1.8:1, I would not bother, as the difference in radiated power is negligible (fraction of an S-point).

Because of the short wavelength, 10m antennas don't have to be that high to be effective. When the band is in good shape, worldwide DX can be had with simple wire antennas and low power. It is a rewarding band.  What is more, 10m multi-mode transceivers can be bought at low cost.  In summary, 10m is unique: low cost transceivers, simple antennas and good DX potential.

1 comment:

Anonymous said...

Far too technical for today's amateurs.