Band i
Waterfalls
 One of the products of using PC software to monitor exact video carrier frequencies is the waterfall display. A typical western European modern transmitter will produce a steady pure tone and if the signal is sufficiently strong enough 50Hz sidebands can be seen either side of the main carrier getting progressively weaker the further away they are from the fundemental. Even with these, many aren't locked to a reference signal and will drift through the day, presumably as the environment around the transmitter warms and cools. Some will drift cyclically over a relatively short period and using slower sample rates a clear indication of the drift can be captured.

In contrast to these many of the old ex Soviet and Russian transmitters really do sound as if they are on their last legs, not only do they drift up and down within their offset slot but many appear to have a life of their own. Some of the finer examples are shown below. As you'll see each one has it's own characteristics and after a short while it becomes quite easy to spot an individual transmitter purely by watching its waterfall display.

For more information on how to quickly and accurately measure video carriers please click here.

Clicking on each thumbnail will take you to a more detailed look of each channel.