Merlin Integrated Signal Processor ISP-100, User Manual

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8-44
10 July 1998
Detection Window is adjustable in the range 20 µSec (one
sample) to 5 Sec.
Metering
The gate meter shows the attenuation applied to the signal passing
through the gate at any given moment in time. When the signal is
below threshold and the gate is closed, the meter indicates negative
values (gain less than 1.0). When the signal is above threshold and
the gate is open, the meter indicates 0 dB (gain of 1.0). Meter values
are raw, no averaging or ballistics are applied.
Notes on Operation of the Gate
Bypass
Bypassing a gate causes the signal to pass through unaltered.
Computation of Average Level
There are two common methods of computing average signal
level; one is based upon RMS (Root Mean Square) calculations,
and the other is based upon Absolute Value calculations. Each
of these methods produces a slightly different value for signal
level, and the difference depends upon the characteristics of the
signal itself. The ISP-100 gate uses Absolute Value for its
computation of signal level, so the level reported by the gate
may differ slightly from the RMS value expected for a given
signal.
Keying from Other Channels
When the key channel input to a ISP-100 gate is selected to be
a channel other than its input, the gate controls must still be set.
The key channel selects only the channel’s data, not its gate
control settings. If multiple gates utilize the same channel as
their key sources, then all controls on all gates must still be
configured.
Metering
The meter located to the left of the component indicates the amount
of attenuation in dB.
Attenuation and Threshold Controls
These controls can be adjusted three ways:
Using the Slider
Click on the indicator on the slider and while continuing to hold
down the mouse button, move the mouse up and down. The
numbers in the box below the slider will change. When the
desired level is reached, release the mouse button.
Using the Text Box
Click in the box. Using the Back Space and/or Delete keys
erases the current entry and enters the new level. Be sure to
press the Enter key after the entry is made. Clicking outside the
text box without pressing the Enter key will cause the setting to
return to the number that it was before a change was attempted.