Roland SH-5 - VCO-1 Frequency Adjustment

1976-10-30 SH-5
NOTE: 1. If during the procedures the TUNE control goes all the way to the stop, reset it at center and use
the FREQ control once; then use the TUNE again in successive steps.
2. When F1 and F2 are correct, repeat the above procedures for F1 and F4. This may prove easier to
do using the screw driver adjustments on the front panel since the front panel WIDTH control is
only 1k£2. When F1 and F4 are correct, check that all F keys are correct. With the FREQUENCY
COUNTER, the frequencies are: F1 = X; F2 = 2X; F3 = 4X; F4 = 8X
FREQUENCY COUNTER METHOD
Press F1; adjust FREQ and/or PITCH for a convenient reading (such as 100Hz.); call this "X"
(VO-3)
(op-20)
FREQUENCY COUNTER
Press F2, note frequency; correct reading is 2X. If the reading is high, adjust VR-302 so it is a little higher; if
low, a little lower.
Press F1. If necessary, adjust VCO frequency for a reading which is easy to double mentally
Repeat the above steps until F2 reads twice F1 ±1 Hz
OSCILLOSCOPE/AUDIO GENERATOR METHOD
Connect the VERTICAL input lead to Terminal 23 on VO-3. Connect the HORIZONTAL lead to an audio
generator. Set the generator for about 175 Hz.
Press F1; adjust FREQ for stable 1 : 1 Lissajous figure.
Press F2; Adjust VR-302 so the speed of the rolling increases slightly.
CAUTION: If the figure is turning slowly, be careful not to turn VR-302 in the direction which causes the
pattern to reverse direction.
Press F1; adjust VCO frequency VR-17 for a stable 1 :1 Lissajous figure.
Repeat the above steps until the figures for F1 and F2 remain stable.
VCO-1
WIDTH
(VR302)
VCO-2
I WIDTH
I (VR403)
AUDIO GENERATOR
-40-
Scan by Manual Manor
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