Time to get this site upgraded, so we are passing the hat around. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html
We appreciate your help
in keeping this site going.
15,750 Hz. Couldn't say how much range with your design.The trimmer is likely in parallel with a fixed cap. That cap might be too far off for the trimmer to compensate.
Does the trace look OK (like I know what I'm doing!)
It looks like the picture is getting somewhat better