Well, the sweep used to start at 20, and held for one second before carrying on, and I could clearly see it down at the bottom of the scale. However, I don't really know what the scale is meant to be displaying. Toby indicated that it was not really a serious display, just for fun, and you couldn't count on the calibration of the scale. Hence, you would be better off by determining which band centres you would actually like to use, then creating a sequence of tones of say 1-2 second duration. This would let you calibrate the frequency scale, at least. This was my intent, so that if we could place an image behind the scale, we could see specific frequency markers.

It's interesting to note that the HSX109 has a spectrograph visual, with a calibrated frequency scale. It's supposed to use a common code base with the car - the only major difference being the display resolution (which would make the text graphics difficult). How about it, Toby?