The LFO does not require any setting up other than the option to adjust the value of R503 and hence the minimum frequency at which the LFO will run.
Selection
of R503
The
value of R503 determines the minimum integrator input voltage that can
be set by P501, and hence the minimum frequency of the LFO. The value
of R503 must not be chosen too high or the minimum LFO frequency will
be too great. On the other hand it should not be chosen too low, or
the integrator input current at the minimum setting of P501 will be
comparable with the input currents of U501. This will result in unreliable
operation of the oscillator at low frequencies.
R503
should be chosen so that the minimum frequency of the LFO is about one
cycle every three minutes, but the value of R503 should not, ideally,
be less than 10R. If it is not possible too obtain this low frequency
then the input currents of U501 may be too high, or C501 may be leaky.