Motorola CDM1250, Basic Service Manual

Page: 47 / 92

Radio Programming and Tuning Procedures 4-5
Table 4-3: PA Bias Specifications*
*These values are up-to-date as of the print date. For the latest values and procedures, refer to the
Tuner online help.
4.4.2 Reference Oscillator Warp
This procedure affects all deviation values such as DTMF and MDC1200 signaling as the frequency
will drift if not warped properly.
Perform the oscillator warp procedure as follows:
1. Under the Tx Align menu, select Reference Oscillator Warp .
2. There is only one frequency point shown. This is always the last frequency point (F7).
3. Click on the slider thumb. Press PTT Toggle to key up the radio at the corresponding frequency
point.
4. Monitor the transmit frequency.
5. Adjust the slider, spin, or edit control until the frequency is as close as possible to the indicated
transmit frequency. Refer to values listed in Table 4-4. Press
ENTER to confirm the selection.
6. Dekey the radio by pressing PTT Toggle .
7. Program the warp value into the radio by pressing the Program button.
8. Exit the reference oscillator warp function.
RF Band PA Type
Voltage
Value
Bias 1
Current
Bias 2
Current
Bias 3
Current
UHF (403-470 MHz) 25-40W 95 100-150mA 130-170mA Not Used
UHF (403-470 MHz) 1-25W 95 Not Used 130-170mA Not Used
UHF (450-512 MHz) 25-40W 95 100-150mA 130-170mA Not Used
UHF (450-512 MHz)
(VMOS) 1-25W 95 100-150mA 130-170mA Not Used
UHF (450-512 MHz)
(LDMOS) 1-25W 22 Not Used 370-430mA Not Used
VHF (136-174 MHz) 25-45W 85 100-150mA 100-150mA Not Used
VHF (136-174 MHz) 1-25W 55 Not Used 80-120mA Not Used
LowBand (29.7-36
MHz) 40-60W 63 100-150mA 100-150mA 100-150mA
LowBand (36-42 MHz) 40-60W 63 100-150mA 100-150mA 100-150mA
LowBand (42-50 MHz) 40-60W 63 100-150mA 100-150mA 100-150mA
Note: 1. Tuning of the PA BIAS must be performed first.
2. This operation should be performed prior to all other transmit tuning operations
to minimize heating and the impact of warp on signaling operations.
3. If the output power level is too low to measure the frequency, tune the transmit
power for the highest frequency first. However, if this is done, a wait period is
required to allow the radio chassis to cool down to approximately 25 °C before
setting the Reference Oscillator Warp.