I ordered a 10 pack of 3560 crystals (HC/49 style) from 3rd Planet Solar
on eBay. Got them yesterday and finally had a chance to check them out.
NONE will oscillate in the Cricket. The crystals aren't bad (they
oscillate & check good in my crystal checker) they just won't run in the
Cricket. I don't know if it's a feedback problem that needs a component
change or if it's just that there's not enough drive. They will
sometimes try to start and once in a while one of them would run in RX
mode but as soon as you hit the key to transmit (good 50 ohm dummy load
attached). The crystal would stop oscillating and it would be necessary
to cycle power to shock it back into oscillation. Maybe Dave, NM0S
would chime in on this since I'm not an engineer and don't know for sure
which component values to change in an attempt to make these crystals
work.

Jim - W0EB