My grid dip meter can measure just over 300MHz. Plan was to do one last LC that resonates near the meters upper limit. Rather than the 68nH, a 6.8nH was used with the same 39pF ATC part. This should be a bit over 300MHz except for the parasitics, tolerance.....
Pic1 showing one of the the weak coupling caps. These are a 1pF NPO 06035A1R0CAT2A. See datasheet:
https://datasheets.kyocera-avx.com/C0GNP0-Dielectric.pdfPic2 removing mask and adding a small extender tab for the inductor to rest on.
Pic3 showing the 300MHz coil on the grid dip meter along with the new tank.
Pic4 Looks like it resonates just under 300MHz.
Pic5 showing completed tank attached to the LiteVNA
Capture3 Running an uncalibrated wideband sweep to get some idea what it looks like. Looks like it resonates near 295MHz.
Capture4 The LiteVNA has been calibrated. The peaks centroid measures 294.838MHz. The width measures 7.25MHz giving us a Q of 40.7. The data sheet shows it around 30 at 300MHz (Capture2).
Capture5 showing the group delay (50 averages) of 44ns. This gives us a Q of 40.7.
Not sure why the Q is so good. Then again, these are typical numbers.