Spectrogram is an audio frequency spectrum analyzer that runs on a PC. The latest version is available from Visualization Software. You can download and evaluate it for 10 days. An earlier version of Spectrogram was released a few years ago as freeware and many people have found it is still very adequate for aligning ham receivers, like the Elecraft K2. You can download this earlier version 5.17 here.
After downloading the zip file to a folder, unzip it and it's ready to go! This is one of the friendliest Windows programs I've ever seen. No installation Wizard, no modifications to your registry, just download and run. Makes you wonder why all Windows programs aren't like this :-) Richard Horne has done a terrific job of coding a very useful program.
There are several parameters that can be set up to suit your taste. Here's a screen shot showing some settings that I've found useful. The "FFT size (points)" selection is one of the most interesting controls that you may want to experiment with.
Here's an example of a display while looking at the audio output of an Elecraft K2 transceiver. The audio signal for the PC sound card can be taken across the headphone jack (with the headphones plugged in) or from the external speaker jack.
Tom Hammond, N0SS, has written several very good articles on using Spectrogram.
Another good tutorial on Spectrogram by John Grebenkemper, KI6WX.
Updated: Mar 30, '04