Water Fall – Dipping Your Toe In It! September 30th, 2013
One of the interesting things about attending the RSGB National Hamfest, is the chance to meet and talk with both customers and suppliers. Looking back on it, all the comments that you receive combine to form a kind of market research. And that is very good and useful to have. One of the things that surprised me somewhat were the number of people that read this blog. That is also a good piece of market research.
I spent most of my time surrounded by Elecraft, Apache-Labs and FlexRadio products. These are all cutting edge products and it was for that reason we had decided to make a dedicated display with the opportunity for customers to get hands on operating experience. And this proved very popular. During this time, something that repeatedly was tested out was the waterfall display.
I come from the days of analogue gear and my first experience of a waterfall display was around ten years ago when I set up a PSK31 system. At that time I viewed the waterfall display as an essential part of PSK31, and it worked very well. In fact it seemed to me the obvious way to display signals. But what I did not appreciated back in those days was that the waterfall display had a lot more to offer.
The traditional panoramic display as seen on SDR systems is very useful and you soon begin to recognize what an SSB signal looks like and the fact that you can spot signals without having to tune back and forth across the band. But when it comes to the weaker signals, these get lost in the general display of spikes caused by a mixture of noise and weaker signals. It is here that the waterfall display becomes so important.
A weak signal shows up as a continuous trace, whereas noise just shows up as part of the background display and even large spikes become insignificant compared to a weak but continuos signal. So if you are monitoring a quiet band such as 10m, 6m or one of the VHF/UHF bands, you can switch on the waterfall display and just glance at it occasionally to see if there are any signals or beacons coming out of the noise. It is fundamentally different in that the waterfall display produces a trace that stays on the screen for up to a minute or so, whereas the panoramic display is just there for an instant.
Time after time, visitors came to our stand and wanted to see the waterfall display and we had to keep the Elecraft P3 switched to the waterfall display for this reason. It is a new way of working for many, but once you become accustomed to it and recognize how signals look on, it becomes an instrument that you cannot afford to do without. Indeed in some modes, it is is absolutely essential. Dip your toes in the water and try it for yourself. Peter G3OJV