7
HARDWARE ALIGNMENT
The alignments are preset at the factory and should not need to be adjusted during installation. However, if an
adjustment is needed please follow the procedures below.
TX Input Line Level Adjustment:
1. With the dedicated line connected to the TTC, connect a line level meter to the red and green (2-wire) or yellow and
black (4-wire option) in bridging mode.
2. Configure the line level meter to generate continuous low-level guard tone (2175 Hz at -20 dBm).
3. Adjust RP13 while monitoring TP10 with an oscilloscope, so that TP10 shows 1.2 V p-p. Also verify that JP-26 Pin 2
shows 220 mV p-p.
TX Notch Filter Alignment:
1. Continue generating the low-level guard tone from the line level meter in the previous step.
2. Monitor TP8 with a Sinadder. The audio level of the Sinadder should be adjusted to hear the tone.
3. Adjust RP9 until the tone is at it’s most diminished point.
4. Adjust RP10 until the tone fully diminishes. If this step does not get rid of the tone go to step 5.
5. Repeat steps 3 and 4 until no tone is heard.
TX Bandpass Filter Alignment:
1. Reconfigure the line level meter to generate a continuous low-level guard tone (2175 Hz at -20 dBm).
2. Adjust RP7 while monitoring TP6 with an oscilloscope, so that TP6 is peaked.
TX Mod Level Adjustment:
1. Reconfigure the line level meter to generate a continuous 1 KHz tone at -10 dBm.
2. With JP25 in the 1-2 position the output impedance is 22 K. For radios with a 600 Ohm impedance put JP25 in the
2-3 position.
3. Adjust RP8 for full system deviation.
RX Input Line Level Adjustment:
1. With voice being received from the base station adjust RP3 while monitoring TP1 with an oscilloscope, so that TP1
shows around 700 mV p-p. Also verify that JP-22 Pin 2 shows around 180 mV p-p.
RX Notch Bandpass Alignment:
1. Generate the low-level guard tone (2175 Hz at -20 dBm) using the line level meter to the RX Input from the radio.
2. Monitor TP2 with a Sinadder. The audio level of the Sinadder should be adjusted to hear the tone.
3. Adjust RP5 until the tone is at it’s most diminished point.
4. Adjust RP4 until the tone fully diminishes. If this step does not get rid of the tone go to step 5.
5. Repeat steps 3 and 4 until no tone is heard.
