signals visible

I was able to display the spectrum from a few MHz to more than 440 MHz. A lot of improvements are needed though.
-signal is not stable on x axis. It jumps around. Probably caused by flyback of sweep.
-Signal strength out of tuner is low
-Sweep is inverted. Highest frequency is on the left of the screen.
These are the worst problems. I hope I can fix them in the weekend.