Filser Electronic GmbH
Gewerbestraße 2
ATR 720 C Communications Transceiver
86875 Waal
page 10
2.Carbon Standard Microphone or Dynamic Microphone with Preamplifier
Using a carbon standard microphone or a dynamic microphone with preamplifier turn the mi-
crophone gain trim-potentiometer R 3104 full
-
counter clockwise -
-
Caution
Do not force microphone selector
2.2.3 Sidetone Adjustment
1. Connect the Unit into the test set-up diagramed in Figure 2-1.
2. Connect the RF wattmeter or a suitable dummy load to J 5001.
3. Key the transmitter and talk into the microphone.
4. Adjust SIDETONE control 5201 for a comfortable listening level from the headphones.
5. Disconnect the Unit from the test set-up.
200
Sidetone Control
255
Mike Gain Control
Figure 2.2 MIKE SELECTOR - SIDETONE CONTROL
2.2.4 External Audio-Frequency Volume Adjustment
When using the external audio-Frequency input (P 3001 Pin 4), the sensitivity of this input may be
adjusted with R 3107, witch is located on the Audio-Frequency/Synthesizer board. R 3107 is pre-
adjusted to o.5 V RMS sensitivity for rated speaker output, which is sufficient in the most cases.
For further details of adjustment see „ATR 720 – Maintenance Manual“ § 4.5.4 and Figure 6-3.
Turning r 3107 clockwise, the sensitivity of this input is to be increased.
