8-44

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.

10 July 1998

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Telex ISP-100 manual Keying from Other Channels, Attenuation and Threshold Controls