S-COM Digital Audio Delay Module (DADM)

Digital Audio Delay Module

[DADM Board]

The S-COM Digital Audio Delay Module (DADM) is an enhanced replacement for the original S-COM Audio Delay Module (ADM/K, ADM/U), and competitive audio delay units. It is the same size and shape as the analog original, and offers much better frequency response and signal-to-noise ratio. Additionally, the DADM contains an on-board audio gate which allows it to become a standalone squelch tail eliminator. This means no external gating or controller is needed in simple applications. A COR (carrier-operated relay or switch) connection is needed from the receiver to activate the audio gate.

The DADM is supplied with a 4-pin male header and 4-conductor cable compatible with the S-COM 5K, 6K, and 7K controllers. An additional wire must be attached to the DADM for COR when the DADM is expected to perform audio gating.

Delay Dipswitch selectable from 12 to 197 milliseconds in 16 steps of approximately 12 milliseconds each.

Audio Levels Nominal input level, 2 V peak-to-peak (0.7 Vrms)
Maximum input level, 4 V peak-to-peak (1.4 Vrms)
Output level same as input level (gain = 1)

Input Impedance Approximately 100K ohms, AC-coupled. Source impedance should be less than 5K ohms.

Output Impedance Approximately 100 ohms. Load impedance should be greater than 5K ohms. The output on pin 2 is DC-coupled with a DC component of 0.45 x Vsupply (compatible with S-COM 5K, 6K, and 7K controllers.) The output on pin 6 is AC-coupled

Frequency Response 30 Hz to 5000 Hz +/-1 dB (guaranteed); 30 Hz to 5000 Hz +/-0.5 dB (typical) over the entire delay range.

Distortion Less than 2 percent (-34 dB) THD (guaranteed);
Less than 1 percent (-40 dB) THD (typical).

Signal-to-Noise Ratio Greater than 60 dB referenced to a 2V peak-to-peak input signal.

Audio Gate External signal may be connected to pin 5 to control the on-board audio gate. Dipswitch selectable for either high-true or low-true control. (Low level is defined as less than 1 VDC; high level is defined as greater than 3 VDC.)

Power Requirements +9.0 VDC to +12.0 VDC at 25 mA.

Dimensions Only 2.1 by 2.7 inches; tallest component is 0.5 inches above the board. Four mounting holes provided for 6-32 hardware.

[Main]

Delay	Dipswitch selectable from 12 to 197 milliseconds in 16 steps of approximately 12 milliseconds each.
Audio Levels	Nominal input level, 2 V peak-to-peak (0.7 Vrms) Maximum input level, 4 V peak-to-peak (1.4 Vrms) Output level same as input level (gain = 1)
Input Impedance	Approximately 100K ohms, AC-coupled. Source impedance should be less than 5K ohms.
Output Impedance	Approximately 100 ohms. Load impedance should be greater than 5K ohms. The output on pin 2 is DC-coupled with a DC component of 0.45 x Vsupply (compatible with S-COM 5K, 6K, and 7K controllers.) The output on pin 6 is AC-coupled
Frequency Response	30 Hz to 5000 Hz +/-1 dB (guaranteed); 30 Hz to 5000 Hz +/-0.5 dB (typical) over the entire delay range.
Distortion	Less than 2 percent (-34 dB) THD (guaranteed); Less than 1 percent (-40 dB) THD (typical).
Signal-to-Noise Ratio	Greater than 60 dB referenced to a 2V peak-to-peak input signal.
Audio Gate	External signal may be connected to pin 5 to control the on-board audio gate. Dipswitch selectable for either high-true or low-true control. (Low level is defined as less than 1 VDC; high level is defined as greater than 3 VDC.)
Power Requirements	+9.0 VDC to +12.0 VDC at 25 mA.
Dimensions	Only 2.1 by 2.7 inches; tallest component is 0.5 inches above the board. Four mounting holes provided for 6-32 hardware.