Saturday, December 27, 2008

Exploring the VHF Radio World

Since heavy ice broke my HF antenna pole last year I have been without any HF communications, being too lazy to repair the pole or replace it. I never used the VHF bands before, so I thought now is a good time to experiment with those bands especially that it is easy to install a small indoor antenna to cover the two bands: 2 m (144 MHz) and 70 cm (430 MHz). The antenna cost about $30 and can be installed on the top of a car using a magnet base. For now I intend to use it indoor only. The gain and VSWR of the antenna are probably not that good but I am hoping that I can communicate using one of the nearby repeaters in the city, and for that I don't need a lot of power or antenna gain.
The main advantage of using VHF bands is the ability to experiment with digital communications, such as RTTY, slow scan TV and ARPS systems. Some amateurs also use VHF bands for moon and meteor scatter, but that is not one of my immediate interests now.
In order to utilize any of the digital modes a TNC (Terminal Node Controller) is needed, or at least that used to be the case. Now a sound card of a common personal computer can be used instead of the TNC to connect with the radio, together with some special software installed in the PC, and the PC itself can then be used to operate the radio in digital mode. Well, I got a collection of digital mode communications software recently and it is time now to use them in the VHF bands.
Before the internet and email, radio amateurs used the digital modes to send text messages just like email. Now of course email is much more efficient, except of course when there is no access to the internet.
In any case, pretty soon I should be able to use the VHF bands and report on my findings. Wish me luck.

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