EMRFD Message Archive 3191

Message Date From Subject
3191 2009-06-15 06:25:52 rotfunkblau Xtal Frequency Shifting (your own xtal frequency)

maybe some of you might be interested in making some special xtal frequency from xtal that are close to the desired frequency.

The following description is experimental.
I have made a few special xtals and use them without serious problems in oscillators.
But that does not mean that I can garantee for any function, for shure Q is worsen.

To shift up frequency of maximum 20khz for 10Mhz xtals:
Electrolytic etching of the silver plated electrodes:
a) careful open the xtal (I use the Dremel tool)
b) solder both xtal connectors together
c) put some alcohol (purity >90%) in a glas
d) connect the plus pole to the xtal leads, the minus pole to a blank copper strip
e) apply about 30V, adjust the current by spacing the xtal and copper strip to about 100uA
f) every minute of applied current will shift the xtal frequency of a 10Mhz xtal about 1kHz
i.e. after 10 minutes you have about 10khz upwards shift
g) if all the silver plating has gone the xtal is ruined
h) test the frequency of operation by drying the xtal and inserting in a test circuit.
i) after having reached your freq. careful dry the xtal
j) resolder careful the xtal case, make sure that it is gas tight and there are no connections
from the xtal lines to the case (use ohm meter to check). Resoldering will shift the freq. down only a few

Instruction for down shifting can be found at

73 de Guenter
3224 2009-06-20 03:30:39 Alex Re: Xtal Frequency Shifting (your own xtal frequency)
many thanks for interesting post, very useful for homebrewer..


Alex I0SKK