>No phase noise is introduced into the circuit for it is merely a
>correction of frequency about a set frequency using a varactor diode.
The added varactor circuitry will introduce additional phase noise,
from both leakage current in the varactor and noise on the varactor
bias (just from the new bias supply, if you use a varactor that was
already there). Perhaps not enough to be problematic, but it will be
clearly measurable unless the original circuit was badly designed.
TenTec mailing list