Saturday, August 16, 2008

HF antenna height improvements

antenna.jpgDid some work on my 20m (14Mhz) dipole antenna and managed to raise it about another meter above the (2nd story) roof.

The difference is clearly noticeable in reception, the background noise level is reduced - meaning I can hear stations I previously couldn't and early reports of my transmission are that my signal is perhaps 1 S point higher. (I'm a bit wary of that observation as HF radio is extremely variable).

Note that 1 S point is four times the power.

I shouldn't be surprised that the extra hight helps, there's lots of research on this, but I didn't expect it to be so clear.

This new support is the pole from a free standing netball hoop, then an iron pole, and finally an aluminium pole. Up the top is a pulley so I can easily raise and lower the dipole balun with ease.

Anyhow, I'm happily back on 20m PSK31, chatting near and far on 25W.

Incidentally, I'm tired of getting RST reports of "599" all the time. Firstly on PSK31 it's pretty meaningless (a better measure is IMD dB), and secondly how on earth can I be S9 all over the place?

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