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3. PRELIMINARY ADJUSTMENTS AND CALIBRATION
3.1. PRELIMINARY ADJUSTMENTS
3.1. 1. General
Before the instrument is switched on, ensure the voltage selector is set to
the correct line voltage. If not, unscrew the central fuse, and turn the
selector to the desired position with a coin or wide bladed screwdriver.
If necessary, set the needle deflection to zero using the mechanical
adjuster under the meter scale.
Switch on and allow a suitable length of time for the instrument to warm
up; (i.e. a few minutes for normal use, and up to 1 hour if high stability of
the V.C.O. is required).
3.1.2. Frequency adjustment
Set the controls as follows:
The SWEEP CONTROL selector to "Manual".
The FREQUENCY SCALE selector to "Log x 1".
The MAl N SCALE POl NTER exactly to 0.02 kHz (the left hand end
of the scale).
The FREQUENCY INCREMENT control should be in a neutral (zero)
position, if not adjust until the middle lamp is lit.
Then the Nixie display should register 0.0200 kHz (the highest resolution
should be selected by depressing the COUNTING TIME INCREASE push-
button).
If the display does not register this frequency, adjust the FREQUENCY
ADJUSTMENT potentiometer with a small screwdriver until this reading is
obtained.
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