🚀 go-pugleaf

(Terry Ingoldsby writes:
>indicated an oscillator that seems to be controlled by a
>small, green, square edged device on the printed circuit
>board, about .7 cm wide, .3 cm thick and .5 cm high.  The
>device appears to be a ceramic capacitor EXCEPT for the
>fact that all other caps on the board are silk-screened as
>C1, C4, etc. and this one is called Y01.
	Well, you have definitely found the frequency-setting
component.  It is a crystal resonator made of a polycrystalline
material (ceramic), and "poled" into the correct behavior by
electrical biasing while it was being boiled in oil...
Such ceramic resonators, and the similar ceramic filters, are
cheaper than quartz crystals, and more than accurate enough
for most applications.  The "Y01" is a crystal designation,
and I guess the ceramic components are close enough to qualify.
	Usually a replacement for such a component would
be a "pi" network; input node to capacitor to ground and to
an inductor, other end of inductor to capacitor to ground, and
to the output.  Replacing the inductor with a quartz crystal, this
becomes a parallel resonant crystal circuit.  If you want to
change the value, find capacitors and an inductor such that
1/SQRT(L * C) = 2*pi*<frequency>
where 1/C= 1/C1 + 1/C2 for the two capacitors
Depending on the nature of the resonator, it may have external
capacitors already connected in the appropriate spot.
	Good luck.

I am known for my brilliance,                 John Whitmore
 by those who do not know me well.