Studio Technologies ISS - Manual (Page 37)

Issue 3, June 1990 ISS User Guide
Page 38 Studio Technologies, Inc.
ISS
Appendix B
ISS Alignment Notes
Stereo Simulator Card Alignment
A number of trim potentiometers are factory
adjusted on the Type I and Type II Simula-
tor Cards. These pots do not require adjust-
ment unless parts have been changed due
to repair of the Simulator Card. Changing
the setting of any pot without going through
the entire procedure can cause incorrect
operation of the Simulator Card and ISS
System.
Type I and Type II Cards
Stereo Simulator Cards are built as Type I
or Type II. The same raw printed circuit
board is used for each version. The Type II
Card contains a band dip filter; the Type I
does not have the parts for the filter in-
stalled. Several minor differences between
the two cards are also present but do not
effect alignment.
Materials Required for Alignment
Procedure for Type I Card
1) Place the Type I Simulator Card onto
the Extender Card System. Refer to the
ISS Technical Manual for Extender Card
installation details.
2) Turn the ISS mains power on.
3) Set the ISS to: I/O Normal, mode to
MAN, SIM LEFT.
4) Set R4 and R43 to 50% clockwise; R18
to 75% clockwise.
5) Connect the signal generator output to
the ISS left channel line input, located
on the back of the ISS.
6) Set the signal generator frequency to
1kHz, with output level to OFF so that
no signal is getting sent to the ISS left
line input. The signal generator signal
must be a sine wave.
Checking the Power Supply Voltages
With the DC voltmeter common lead con-
nected to COM test point: check +15 test
point for +15 ±1Vdc, –15 test point for
–15 ±1Vdc.
Checking for the Correct Rough Setting
of the Compander
1) Again insure that no audio is coming
into the ISS.
2) With DC voltmeter common lead con-
nected to COM test point: check TP5
for 1.35 ±0.3Vdc. If not within this
range, set R69 to give 1.35Vdc at TP5.
3) With DC voltmeter common lead con-
nected to COM test point: check TP7
for 1.35 ±0.3Vdc. If not within this
range, set R56 to give 1.35Vdc at TP7.
Setting the Analog Delay Clock
Frequency
1) Connect common lead of frequency
counter to COM test point. Check TP2
for 119.5kHz ±0.5kHz. If not within this
range, set R20 to give a value in this
range.
Adjusting the Incoming Audio Test
Signal
1) Connect the AC voltmeter common
lead to the COM test point.
2) Adjust audio generator output level to
give –10dBu reading at TP3.