Transmit Deviation Balance (Compensation); Table 6-3. Current Limit Step Adjustment - Motorola MCS 2000 Service Instructions Manual

6-6
3. For all models except UHF 40W and 110W, input a value of 0 and press F8 (this corresponds
to minimum current cutback). Press F6 and note the output power. Input a softpot value of 15
(press F8 to program); if the output power decreases more than 5%, return the value to zero.
Next, increment the softpot value using the UP arrow key to adjust current limit until a 5%
drop in output power is noted. Decrease the current limit softpot value by the number of steps
defined in
For UHF 40W and 110W radios, input a value of 63 and press F8 (this corresponds to mini-
mum current cutback). Press F6 and note the output power. Input a softpot value of 50 (press
F8 to program); if the output power decreases more than 5%, return the value to 63. Next,
decrement the softpot value using the DOWN arrow key to adjust current limit until a 5%
drop in output power is noted. Increase the current limit softpot value by the number of steps
defined in
4. Press F6 to dekey the radio.
5. Press F8 to program the value. (The six other test frequencies do not need tuning for cur-
rent limit. The above procedure sets current limit for all frequencies).
6. Press F10 twice to return to the SERVICE menu.

Transmit Deviation Balance (Compensation)

Compensation alignment balances the modulation sensitivity of the VCO and reference modulation
(synthesizer low frequency port) lines. Compensation algorithm is critical to the operation of
signaling schemes that have very low frequency components (e.g. DPL) and could result in distorted
waveforms if improperly adjusted.
1. Press F4 to select the TRANSMIT DEVIATION BALANCE softpot. The screen will indicate
the transmit test frequencies to be used.
2. Begin with the lowest test frequency shown on the screen.
3. With Test Box RLN4460A: Set the test box METER OUT switch to the MIC position, and
inject a 80 Hz tone at 100 mVrms into the AUDIO IN BNC connector. To ensure proper signal
level measure on METER OUT jack with AC voltmeter.
With Test Box GTF180B: Set the Test Box meter selector switch to the "GEN" position, and
inject a 80 Hz tone at 100 mVrms into the "Audio In" port. Connect an AC meter to the meter
port to ensure the proper input signal level.
4. Press F6 to key the radio, then press F8 and measure deviation. Record this measurement.
5. Press F6 again to dekey the radio, and change the input tone to 3 kHz, 100 mVrms.
6. Press F6 to key the radio, then press F8 and use the UP/DOWN arrow keys to adjust the
deviation to within ±0.15 kHz of the value recorded in Step 4.
7. Press F6 to dekey the radio, and press F8 to program the softpot value. Press ENTER to
move to next softpot value.
8. Repeat steps 3 - 7 for the remaining test frequencies.
December 6, 2004
Table 6-3.
Table 6-3.
Model
VHF
UHF
800 MHz/900 MHz

Table 6-3. Current Limit Step Adjustment

Radio Tuning Procedure: Tuning Procedure
Power
all power levels
all power levels
all power levels
Steps
3
4
3
68P81083C20-D