Shifting Frequency of a VHF Crystal?

Question

I have a boatload of 165.550 MHz Regency 10.7 MHz IF Crystals. I need them to resonate for 165.500 MHz. How can I shift the crystal frequency down 50 KHz without opening the 'tincan' and messing with it? Can I add a small capacitor in parallel to shift the crystal frequency down? How can I determine the value of the Cap? Likewise, is there a rule of thumb in order raise the frequency of a crystal? Is 50KC too big of a jump? Thanks Much, 73 J

Answer 1

You can add inductance in a sequence like this.

^{simulate this circuit – Schematic created using CircuitLab}

Yes, you can also try adding capacitance in parallel.

Answer 2

I assume these are 3rd or 5th overtone crystals. It is not possible to pull overtone crystals that far in frequency. You can generate one fixed frequency from another one but the effort to do that is considerable, compared to a simple crystal with the correct resonant frequency.