RF Crystals...?

i need a 58 mhz rf crystal for a project i got off the internet, but the catalog i'm going to order from doesn't have that frequency. what i want to know is if you can connect crystals in parallel to build up to a frequency, like in capacitors you put them in parallel to get a higher value. all i really need is understandable formulas. anyone know anything about this? thanks

The quartz frquency depend from mechanical size, no possible tuning. Apply a PLL with programmable divider.

I don't think that paralleling crystals will do it. I am not sure what the application is but for some applications the cystal is 1/2, 1/3, 1/4, etc of the desired frequency and the circuit acts to double, triple, quadruple, etc the fundamental frequency of the crystal. An example: use a 19.3333 mHz crystal at it's fundamental frequency and triple it to get 58 mHz. Crystals are also made to run at "overtone" frequencies - some approximate (but not exact) integral multiple of the fundamental frequency - however the manufacturer will state this because the cut of the crystal is different. Note that the exact crystal frequency is quite dependent on the circuit - not sure whether precision is an issue for you.

Crystals and Divider Chains

Try buying a crystal with a higher frequency and then using a CMOS or TTL divider chain to reduce it.