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Radio Design Labs RDL ST-GCA3 Gain Control Amplifier Line Level Audio Adjustment

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Radio Design Labs RDL ST-GCA3 Gain Control Amplifier Line Level Audio Adjustment
Grade B condition. Comes as pictured.


The ST-GCA3 constantly adjusts for changes in input levels, bringing up low levels, and reducing gain for high levels. The audio level is constantly adjusted to maintain the correct output. The AGC adjustment rate is switch-selectable. Making audio levels uniform and consistent improves the performance of nearly any type of audio system, and the ST-GCA3 SLOW mode is ideal for leveling music sources. The FAST setting of the ST-GCA3 makes it ideal for use in systems prone to loud bursts of audio, and inconsistent levels which must be constantly and quickly corrected. In paging systems, intercom systems, and mic mixing applications where intelligibility is a must the ST-GCA3 FAST mode can be the key to optimum performance.


+4 dBu balanced (nominal);
-45 dBu to +20 dBu for rated output

Maximum Input Level:
+26 dBu

Outputs (2):
+4 dBu, 150 Ω balanced LINE (nominal, +0/-3 dB);
-45 dBu balanced MIC into 150 Ω

AGC Range:
> 40 dB (output level maintained within 3 dB)

Frequency Response:
10 Hz to 20 kHz (± 0.75 dB)

No input signal, output un-muted: < -70 dB
No input signal, output muted: < -80 dB
Input signal present, output muted: < -50 dB

< 0.3% (50 Hz to 20 kHz; Typ. 0.05% @ 1 kHz)

Mute Threshold:
-46 dB below max input; -28 dB below normal input

Muting Response:
15 sec. for 50 dB

SLOW AGC response:
8 sec. for 20 dB average level adjustment

FAST AGC response:
3 sec. for 20 dB average level adjustment

On Delay:
50 ms to ramp from muted to fully on condition

Indicators (2):
LED, green variable intensity shows audio expansion
LED, yellow variable intensity shows audio gain reduction
Note: Both LEDs display equal intensity for normal input level (equal available expansion and gain reduction).

Ambient Operating Environment:
0° C to 55° C

Power Requirement:

Height: 0.7 in. (1.7 cm), Width: 3 in. (7.6 cm), Depth: 1.6 in. (3.9 cm)