Studio Technologies ISS - Manual (Page 19)

Issue 3, June 1990 ISS User Guide
Page 20 Studio Technologies, Inc.
ISS
If SLOW is OK but you want to change the
IMMEDIATE speed, remove R8 and in-
crease its’ value if you want a slower speed
(longer RC time constant), or decrease its’
value if you want to speed it up (shorter RC
time constant).
Recognition Card Adjustment
The Recognition Card recognition criteria
has been factory set for what we feel is
optimum performance. The Left Only and
Right Only recognition characteristics are
fixed by the design of the circuits. There is
no provision for changing their perfor-
mance. The L=R recognition circuit does
contain a calibration trim pot. This pot, R10,
adjusts the sensitivity of the L=R recogni-
tion. The sensitivity determines when L=R
is recognized. It is factory set at 50% of
rotation. If you determine that stereo
signals are being recognized as L=R,
adjust R10 counterclockwise. This serves
to desensitize the circuit. If two channel
mono signals are not being recognized as
L=R, adjust R10 clockwise. This increases
the sensitivity of recognition. Be certain that
you really need to adjust this control. The
factory setting should give the best overall
performance.
Non-Standard Input and Output Levels
Studio Technologies designed the ISS to
match the audio operating levels of most
broadcast facilities. If you are the creative
type who likes to experiment, or the unlucky
one who inherited a station that has an
operating level different from 0, +4, or
+8dBu (ref. 0.7746V), don’t despair. The 0,
+4, or +8 settings are used to optimize ISS
performance, and using a slightly different
operating level will make only minor differ-
ences in performance. If you are within two
dB of one of the ISS’s preset levels, set
the input and output switches to the closest
value. If you are exactly in between two
of the choices, go for the lower one. An
example would be a station running +6.
Set the input and output levels for +4. If
you are running an operating level below
–2 dB or above +10dB, contact Studio
Technologies for details on simple I/O
Card operating level modifications.
I/O Bypass versus Bypass
Frankly, when we named two ISS functions,
we inadvertently created a confusing situa-
tion. In this section we hope to clearly
explain just what we meant. Once you see
the similar names with different functions we
hope that long-term confusion will be mini-
mized. As penance, the designers have
spent one weekend listening to the Greatest
Hits collections of Donnie and Marie, The
Turtles, and The Kingsmen. Extra time was
put in trying to figure out the actual words
to “Louie Louie.”
I/O Bypass: I/O Bypass is the name we
chose for a function performed by the I/O
Card and the Transfer Relay Assembly.
Relays on the Transfer Relay Assembly
connect the ISS audio inputs to the ISS
audio outputs in the event of a system
failure, operator request, or remote control
request. The I/O Bypass is a hard (relay
contact) bypassing of the ISS circuitry.
During normal ISS on-air operation, the
I/O Bypass mode will rarely be invoked.
Bypass: Bypass is the name we chose for
a function performed by the Crossfade
Card. When the ISS is in the Bypass mode
the crossfade circuit electronically connects
the left and right audio inputs to the left and
right audio outputs. This is an electronic, or