--- In ultralightdx@..., "nhpdxr" <nhp@...> wrote:
A series cap will reduce the available tuning range with the on-chip varactor, too. When you connect two capacitors in series, the total capacitance is less than the smaller of the two. Because the series capacitor has a constant value, the higher capacitance of the varactor, used to tune the low end of the band, is modified by a higher percentage than the minimum capacitance used to tune the high end of the band. That could explain why even your large inductor couldn't be resonated at the low end. If the series capacitor is small enough, the varactors won't have enough range to tune the inductor across the band.
Somewhere on that board is a tiny chip cap. Intuition says it ought to be 0.1 uF or greater. Wonder what they actually used? It might be possible to bridge it with a leaded cap; 0.1-uF ceramic caps are tiny. But a high-Q chip cap of the correct value is only about $1.50, though they are hard to handle, being very small.