As seen in Electric Radio: A Quartz Crystal Replacement Alternative (Jan 2018)
Where have all the crystals gone? Sadly the manufacturers of crystals for the amateur and experimenter have largely folded their tents.
Not to worry. Hayseed Hamfest LLC has teamed up once again with W9RAN's RAN Technology to offer the following easy to build four frequency oscillator board in kit form. The board will hold up to four (4) programmable frequency oscillator chips (not included - available for under $5.00 each from Digi-Key). These PLL frequency sources can give you a super-stable quartz crystal substitute in many radios. Any frequency from 1 to 125 MHz may be specified
All input and output signals are buffered to protect the oscillators from inadvertent damage. The output is a clean 5 volt P-P signal that has proven suitable for driving mixers, up- and down-converters, receiver LOs, channelized transceivers and transmitters as a crystal substitute. (External amplification may be required to drive some transmitters to full output; also, these oscillators may not be shifted in frequency such as for clarifier or FM modulation).
The four-channel board is provided as an easy-to-build kit - No surface mount components - All through-hole construction - IC's are socket mounted. Overall size is 2" by 2" by < 1/2" high so it can be mounted inside many radios.
With fewer manufacturers providing custom quartz crystals, the four-channel oscillator board is a flexible alternative for many frequency control needs.
Suitability for a given application and specification of correct oscillator frequency is the responsibility of the user. Requires 8-18VDC at 100ma source (not included).