How to use a "Waterfall-Display-Software" for Beacon Monitoring

The following describes how I use sound card "waterfall-software" for 10 GHz beacon monitoring. It does - of course - also work on other bands and not only for beacons. The software I use is Spectrum-Laboratory by DL4YHF (Freeware, download it here). I will not go into details abt the software itself as it comes with a comprehensive help file.

I use an Icom 706 or a TS850 with LT2S as the IF-Radio. The 850/LT2S combination has the advantage that the AGC can be switched off, otherwise the IC706 is just fine (and much smaller..). The audio is taken from the ACC connector and fed to the PC sound card line in terminal via a 1:5 NF transformer. Any other similar interface will work. If you dont know how to build such interface go to www.google.com and search for "psk31 interface" and you will find many info.


DB0HEX, seen with SSB filter

The beacon DB0HEX, 248 km away, seen under normal conditions and SSB bandwidth.


DB0HEX, seen with CW filter

The same but with CW filter.


DB0HEX slight above normal

About an hour later the signal strength rises.


DB0HEX, elevation scan

changing dish elevation from -5 degrees to +5 degree and back. Signal rises from the noise getting louder... and so on. As I have a not very trustable elevation readout I adjust the dish to zero horizon (maximum beacon signal) every once in a while. Using the waterfall to do this is much more accurate then doing it just "by ear".



Beacon OK0EW

The beacon OK0EW, abt 90 km distance. The carrier is a single tone while the keying changes amplitude and tone frequency.


DB0TUD, windmill reflections

The local beacon DB0TUD, the dish pointed 10 degree offset into a windmill electrical power plant. The direct signal is at 980 Hz, the horizontal lines are reflections with alternating doppler shift, introduced from the rotating blades. The width of the doppler shift varies with the wind direction (the reflection angle).

beacon DB0FGB - inaudible

The beacon DB0FGB, not audible at all, just a faint trace. The 70 Hz frequency swing with 140 sec periode is probably caused by my very "stable" homemade OCXO, dunno what the problem is, to much loop gain in the temp. regulator, unsufficiant temp. coupling between heater and crystal, or something else. Could also be ref. freq. drifting of the sound card but I think this is unlikely the problem... its something to be figured out... Most people using OCXO will not even notice such minor freq. changes as they are hardly heared by ear (within that time range)....