Transmit Power Tuning; Power Amplifier (Pa) Voltage Limit Tuning (Vhf 1-25W And Uhf 1-25W Ldmos Radios Only) - Motorola CDM Series Basic Service Manual

Radio Programming and Tuning Procedures

4.4.4 Transmit Power Tuning

Note: 1. Tuning of the PA BIAS must be performed first.
2. DAC Tuning must be performed first (LowBand radios only).
3. IMPORTANT: To set the transmitter power for customer applications use the Cus-
tomer Programming Software (CPS). The following procedure should only be per-
formed if transmitter components have been changed or the radio does not
transmit with the power set via the CPS. This tuning method is performed for mul-
tiple Transmit Power Tuning Channels.
4. The power values displayed after opening the screen may have a small rounding
offset.
5. When checking the RF power output of the radio with a test set, always use a pad
of at least 30dB attached to the radio end of the RF cable. This will avoid any RF
mismatch and ensure a stable RF reading that will not change with varying
lengths of connecting cable.
Perform the transmit high power tuning procedure as follows:
1. Under the Tx Align menu, select Transmit Power, then select K and M Tuning.
2. Select the Power 1 box for the first frequency (F1).
3. Press PTT Toggle to key up the radio.
4. Observe the power level (W) displayed on the power meter. Record this value as X.
5. Key in the value X in the Power 1 box.
6. Select the Power 2 box for the first frequency (F1).
7. Observe the power level (W) displayed on the power meter. Record this value as Y.
8. Key in the value Y in the Power 2 box.
9. Press PTT Toggle again to dekey the radio.
10. Repeat Steps 2-9 for frequency points 2 to 7.
11. Press Program to store all keyed in values into the radio.
12. Exit the K and M tuning function.
4.4.5 Power Amplifier (PA) Voltage Limit Tuning (VHF 1-25W and UHF 1-25W LDMOS
radios only)
Note: 1. Tuning of the transmit power must be performed first.
2. This method automatically tunes all PA Voltage Limit Tuning Channels.
Perform the PA voltage limit tuning procedure as follows:
1. Under the Tx Align menu, select PA Voltage Limit.
2. Press Auto Tune and wait until all PA voltage limit softpots have been tuned.
3. Exit the PA voltage limit tuning function.
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