Hytera MD78X, Service Manual

Page: 268 / 519

Tuning Description
UHF3 (350
–
400 MHz)
50
Items Method
3. Click the “Transmit On” button on Tuner.
4. Adjust the power to the required level as follows:
Low power: 1 W (for version D/F); 5 W (for version H or later)
Medium power: 25 W
High power: 45 W
5. Click the “Save” button on Tuner to save the existing value to the radio.
Transmit-to-Deviation
1. Connect the radio to HP8921 via the antenna connector, and set HP8921
to TX test mode.
2. Set the parameters on the HP8921 as follows:
IF Filter: 230 kHz
Filter1: <20 Hz HPF
Filter2: <15 kHz LPF
De-Emphasis: off
3. Open the Tuner software and go to “TUNE_DATA -> TX ->
Transmit-to-Deviation” in the left navigation tree. Then click the “Transmit
On” button. Then set the modulation signal of HP8921 to “100 Hz”.
4. Adjust the vernier on Tuner until the frequency deviation displayed on
HP8921 is “5 kHz”.
5. Click the “Save” button on Tuner to save the existing value to the radio.
6. Click the “Transmit Off” button on Tuner.
Modulation Balance
Here takes the low frequency
deviation
for example.
1. Connect the radio to HP8921 via the antenna connector, and set HP8921
to TX test mode.
2. Set the parameters on the HP8921 as follows:
IF Filter: 230 kHz
Filter1: <20 Hz HPF
Filter2: <15 kHz LPF
De-Emphasis: off
3. Open the Tuner software and go to “TUNE_DATA -> TX -> Modulation
Balance” in the left navigation tree. Then select an appropriate channel.
4. Click the “Transmit On” button on Tuner. Then set the modulation signal