• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

RF Crystals...?

Status
Not open for further replies.

bd13

New Member
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
 

Sebi

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

stevez

Active Member
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.
 

afs87

New Member
Crystals and Divider Chains

Try buying a crystal with a higher frequency and then using a CMOS or TTL divider chain to reduce it.
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top