Motorola Sse 5000 6881094c12 A Manual

							Chapter 5 Radio Alignment Procedures
This chapter describes radio alignment procedures for both the receiver and transmitter.
5.1 Radio Alignment Test Setup
A personal computer (PC) and tuner software (RVN4181) are required to align the radio. Refer to the 
Customer Programming Software (CPS) Installation Guide (Motorola publication part number 
6881095C44) for setup procedures for the software, and to the on-line help in the CPS for complete 
field programming information. To perform the alignment procedures, the radio must be connected to 
the PC and to a universal test set. The radio alignment test setup is shown in Figure 5-1.
Figure 5-1.  Radio Alignment Test Setup
These radio alignment procedures should only be attempted by qualified 
service personnel. Failure to perform alignment procedures properly may 
result in seriously degraded radio or system performance.
BNC
 COMPUTERAUDIO GENERATOR
SINAD METER
AC VOLTMETER TX
RX 30 dB PAD
30 dB PAD
RF GENERATORSYSTEM ANALYZER
OR COUNTER
WATTMETER
MAEPF-27212-C
BATTERY
ELIMINATOR
RTL4224
TRANSMIT
RECEIVE
RADIO
PROGRAM/TEST CABLE
RKN4121  or  RKN4122
AUDIO IN SET TO APPROX. 450mV FOR Tx
MEASURE 80mV FOR Tx
TEST SET
RLN-4460_
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5-2Radio Alignment Procedures: Reading the Radio
5.2 Reading the Radio
Select Tuner from the START menu. To read the radio, use the File > Read Device menu or click on 
.
5.3 Tuner Menu
Figure 5-2 illustrates how the alignment screens are organized. To access a screen, double-click on 
the desired screen name in the Tu n e r menu.
Figure 5-2.  Tuner Software Main Menu
5.4 Radio Information
Figure 5-3 shows a typical Radio Information screen. This screen is informational only and cannot be 
directly changed.
Figure 5-3.  Radio Information Screen 
						

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Radio Alignment Procedures: Transmitter Alignments 5-3
5.5 Transmitter Alignments
5.5.1 Softpot
The alignment screens introduce the concept of the “softpot,” an analog SOFTware-controlled 
POTentiometer used for adjusting all transceiver alignment controls.
Each alignment screen provides the ability to increase or decrease the softpot value by using a slider 
or the spin buttons in the New Softpot Value box, or by entering the new value from the keyboard 
directly into the box. The slider bar indicates the minimum and maximum values of the softpot, while 
the Radio Softpot Value indicates the recommended value; see Figure 5-4.
Figure 5-4.  Typical Softpot Screen
Adjusting the softpot value sends information to the radio to increase (or decrease) the voltage in the 
corresponding circuit. For example, left-clicking the UP spin button in the New Softpot Value scroll 
box on the Reference Oscillator screen instructs the radio’s microcomputer to increase the voltage 
across a varactor in the reference oscillator, which increases the frequency.
In ALL cases, the softpot value is just a relative number corresponding to a digital-to-analog (D/A) 
generated voltage in the radio.
Perform the following procedures in the sequence indicated.
NOTE:Some of the following screens may vary depending upon the radio under test and the version 
of tuner software you are using. Refer to the software’s online help.
5.5.2 Reference Oscillator Alignment
Adjustment of the reference oscillator is critical for proper radio operation. Improper adjustment will 
result not only in poor operation, but also in a misaligned radio that will interfere with other users 
operating on adjacent channels. For this reason, the reference oscillator should be checked every 
time the radio is serviced, or once a year, whichever comes first. The frequency counter used for this 
procedure must have a stability of 0.1 ppm (or better). DO NOT switch radios in the middle of any alignment 
procedure. Always left-click the Close button on the screen to 
return to the Main Menu screen before disconnecting the 
radio. Improper exits from the alignment screens might leave 
the radio in an improperly configured state and result in 
seriously degraded radio or system performance.
When keying the radio during a test, always transmit into a 
dummy load.
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							November 11, 20046881094C12-A
5-4Radio Alignment Procedures: Transmitter Alignments
NOTE:Reference oscillator alignment is required after replacing (or servicing) the transceiver board.
To align the reference oscillator:
1. Select the Reference Oscillator alignment screen. See Figure 5-5.
Figure 5-5.  Reference Oscillator Alignment Screen
2. Left-click the PTT Toggle button on the screen to make the radio transmit. The screen 
indicates whether the radio is transmitting.
3. Measure the transmit RF frequency with your communications system analyzer.
4. Adjust the reference oscillator’s softpot value until the measured value is as close as possible 
to the frequency shown on the screen. See Table 5-1.
5. Left-click the Program All button on the screen to dekey the radio and save the tuned values.
6. Left-click the Close button on the screen to return to the Transmitter Alignments menu.
5.5.3 Transmit Power Alignment
This alignment procedure adjusts the transmit power of the radio and must be performed for two 
different power levels (Low and High), at multiple frequencies for each power level, to allow for 
proper alignment across the entire RF band. (The mid-power level is available to be tuned, but it 
cannot be used.) The RF band is divided into frequency zones with a calibration point (value) in each 
zone.
NOTES:
• The same softpot attenuation value will result in different radio output power levels at different 
frequencies.
• All power measurements are to be made at the antenna port.
• Transmit Power alignment is required after replacing (or servicing) the transceiver board.Table 5-1.  Reference Oscillator Alignment
BandTa r g e t
UHF R2 (450–488 MHz) ±100 Hz 
						

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Radio Alignment Procedures: Transmitter Alignments 5-5
To align transmit power:
1. Select the TX Power (Low or High) alignment screen. The screen will indicate the transmit 
frequencies to be used. See Figure 5-6 and Figure 5-7.
2. Left-click the desired frequency field (starting with the highest frequency shown).
3. Left-click the PTT Toggle button on the screen to make the radio transmit. The screen 
indicates whether the radio is transmitting.
4. Measure the transmit power of the radio with your communications system analyzer.
5. Adjust the softpot value until the required power, as shown in Table 5-2, is indicated on the 
communications system analyzer.
6. Repeat Steps 2 through 5 for all frequencies and all power levels.
7. Left-click the Program All button on the screen to dekey the radio and save the tuned values.
8. Left-click the Close button on the screen to return to the Transmitter Alignments menu. Table 5-2.  Transmit Power Settings
Power Level
Transmit Power 
(Watts)
UHF R2 
(450–488 MHz)
Low 2.2–2.4
High 4.5–5.0 
						

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5-6Radio Alignment Procedures: Transmitter Alignments
Figure 5-6.  Transmit Power Alignment Screen (High Power)
Figure 5-7.  Transmit Power Alignment Screen (Low Power) 
						

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Radio Alignment Procedures: Transmitter Alignments 5-7
5.5.4 Transmit Deviation Balance Alignment
This alignment procedure balances the modulation contributions of the low- and high-frequency 
portions of a baseband signal. Proper alignment is critical to the operation of signalling schemes that 
have very low frequency components (for example, PL) and could result in distorted waveforms if 
improperly adjusted.
This procedure needs to be performed at multiple frequencies to allow for proper alignment across 
the entire RF band. The RF band is divided into frequency zones with a calibration point (value) in 
each zone.
NOTE:This alignment is required after replacing (or servicing) the VOCON board or the transceiver 
board.
To align transmit deviation balance:
1. Select the TX Deviation Balance alignment screen. The screen indicates the transmit 
frequencies to be used. See Figure 5-8 on page 5-7.
2. Left-click the desired frequency field (starting with the highest frequency shown).
3. Left-click the PTT Toggle button on the screen to make the radio transmit. The screen 
indicates whether the radio is transmitting.
4. Left-click the PTT Tone: Low button.
5. Measure the transmitted signal deviation of the radio with your communications system 
analyzer.
6. Left-click the PTT Tone: High button.
7. Adjust the softpot value until the measured deviation, when using the High Tone, is as close 
as possible to that observed when using the Low Tone.
Figure 5-8.  Transmit Deviation Balance Alignment Screen 
						

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5-8Radio Alignment Procedures: Transmitter Alignments
8. Repeat Steps 2 through 7 for all frequencies.
9. Left-click the Program All button on the screen to dekey the radio and save the tuned values.
10. Left-click the Close button on the screen to return to the Transmitter Alignments menu.
5.5.5 Transmit Deviation Limit Alignment
This alignment procedure limits the modulation of a baseband signal. It is used for primary 
modulation limiting.
This procedure needs to be performed at multiple frequencies to allow for proper alignment across 
the entire RF band. The RF band is divided into frequency zones with a calibration point (value) in 
each zone.
NOTE:This alignment is required after replacing (or servicing) the VOCON board or the transceiver 
board.
To align the transmit deviation limit:
1. Select the TX Deviation Limit alignment screen. The screen indicates the transmit 
frequencies to be used. See Figure 5-9.
2. Left-click the desired frequency field (starting with the highest frequency shown).
3. Left-click the PTT Toggle button on the screen to make the radio transmit. The screen 
indicates whether the radio is transmitting.
4. Measure the transmitted signal deviation of the radio with your communications system 
analyzer.
5. Adjust softpot value until the measured deviation is as close as possible to 2.83 kHz.
Figure 5-9.  Transmit Deviation Limit Alignment Screen 
						

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Radio Alignment Procedures: Performance Testing 5-9
6. Repeat the above process for all frequencies.
7. Left-click the Program All button on the screen to dekey the radio and save the tuned values.
8. Left-click the Close button on the screen to return to the Transmitter Alignments menu.
5.6 Performance Testing
5.6.1 Transmitter Test Pattern
The Transmitter Test Pattern test is used to transmit specific test patterns at a desired frequency so 
that the user can perform tests on the radio’s transmitter (see Figure 5-10).
This screen contains the following fields:
•Tx Frequency:
This field selects the Transmit Frequency directly in MHz.
•Channel Spacing:
This field allows the user to select the desired transmit deviation in kHz.
•Test Pattern Type:
This field represents the type of test pattern which will be transmitted by the radio when PTT 
TOGGLE button is pressed.
NOTE:Channel Spacing and Test Pattern Type fields will be grayed out while radio is transmitting.
Figure 5-10.  Transmitter Test Pattern Screen
5.6.2 Battery Reading Calibration
This alignment procedure adjusts the calibration factor used by the radio when determining the 
battery voltage. Correct calibration is required to ensure valid operation of the low battery indicator.
Before starting this procedure, make sure that the radio is not connected to the PC.
1. Remove the battery and use a regulated power supply to apply exactly 6.9 V to the battery 
contacts. 
2. Connect the radio to the PC and read the radio (see Section 5.2: “Reading the Radio” on 
page 5-2).
3. Click on the “Auto Calibrate” button to make the radio determine a new calibration factor. 
						

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5-10Radio Alignment Procedures: Performance Testing
4. Click on the “Program All” button to save the new calibration factor.
Figure 5-11.  Battery Reading Calibration Screen