User's Manual Chapter 5

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5. Alignment and Testing

The MX800 test and alignment procedures are divided into two main sections. The first

section is a transceiver level procedure which assumes that the radio is fitted with working

modules. The second section contains the individual module test procedures.

5.1. Transceiver Setup, Calibration and Alignment

This section explains how to setup, calibrate and align the complete MX800 Base Station.

A number of procedures are required to fully initialise the MX800. The following test

equipment will be needed:

1.0 MXTOOLS (MX800 Base Station Programming Utility)

2.0 MXTOOLS User Manual

3.0 RF Test Set (HP 8920) or equivalent

4.0 CRO (Cathode Ray Oscilloscope)

5.0 RF Power Meter (Watts)

6.0 RF Signal Generator

7.0 Multimeter

8.0 +13.8 VDC @ 15 amp power supply

The order of some, but not all, of the procedures is important to ensure correct setup of the

radio. The order of the procedures as described is recommended and those that are critical

are mentioned. If the radio has been previously setup and the dealer intends to recalibrate

and align the radio then steps 5.1.1, 5.1.2 and 5.1.3 can be ignored as the model number,

serial number, configuration and channel information will have already been loaded.

5.1.1. Sending Model Number and Serial Number to the Radio

The model number is entered or updated using MXTOOLS. To edit the model number

select 'Radio Model Number', under the 'Setup' menu. This brings up a dialog box that

the dealer can then enter the model number, according to the configuration of the radio.

(Refer to the MXTOOLS User Manual for additional help)

The dealer cannot alter the serial number as this is factory set.

Summary of content (15 pages)

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5. Alignment and Testing The MX800 test and alignment procedures are divided into two main sections. The first section is a transceiver level procedure which assumes that the radio is fitted with working modules. The second section contains the individual module test procedures. 5.1. Transceiver Setup, Calibration and Alignment This section explains how to setup, calibrate and align the complete MX800 Base Station. A number of procedures are required to fully initialise the MX800.
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5.1.2. Sending Configuration Information Firstly the configuration file for the radio needs to be setup. Using MXTOOLS the configuration information needs to be filled out on the Configuration Screen. This information needs to be saved to a configuration file. If an existing radio already contains the desired configuration then this configuration can be downloaded and saved. This configuration information then needs to be 'Sent to the MX800'.
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the channels is too large then you may wish to calibrate and align every channel. (In most cases this will not be necessary.) Both individual and group alignment will be covered. The channel may be selected via the Channel Screen in MXTOOLS using the software channel select or in hardware via the internal channel dip switch or via the rear channel select. (Refer to section 2.2.2.3 for additional help.) This channel will then be used when performing the following procedures. 5.1.5.
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5.1.8. TX Power Setup The transmitter power setup is used to set the correct power for each channel. This can be done on a per channel basis or all channels can be set at once. Power setup is done using the Channel Screen in MXTOOLS. To complete this test the transmitter output needs to be connected to a power meter. To set all channels at once select the 'Lock Data' option on the Channel Screen.
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Bandwidth CTCSS Option narrow (12.SkHz spacing) medium (20kHz spacing-US) wide (25kHz spacing) Peak Deviation (Hz) YES NO YES NO YES NO 2150 2400 4300 4800 4300 4800 Table 1 - Peak Deviation Settings The setting of the peak deviation is done at 1 kHz for the standard build and 400Hz for the E1A build. If the board is an EIA build this is noted on the motherboard. The modulation balance for both builds is done at 400Hz.
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Examples of incorrect, observed waveforms are as follows: Figure 5-1 - Under (increase level) Figure 2 -Over (decrease level) The waveform when correctly aligned should look as follows: Figure 3 - Correctly Aligned Waveform Choose 'OK' to accept the changes made and then from the Channel Screen choose 'Send Data to MX800'. This then saves the changes that you have made to the radio.
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connected to a RF test set displaying the frequency error. This procedure should be done after the deviation alignment procedure has been done. Transmitter modulation should be disabled. To alter all channels at once use the 'Lock Data'•ption as described in the power setup procedure. Alter the Reference Oscillator Frequency potentiometer until the channel is "on frequency". Choose 'OK' to accept the changes made and then from the Channel Screen choose 'Send Data to MX800'.
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Procedure i) PTT the transmitter. ii) Set the transmitter modulation frequency to lkHz, at 1V pk-pk injected in the WB/DC-FM input. iii) Adjust TX Limiter gain RV2 to obtain to obtain the nominaI deviation. (See .Table 2 - Nominal Deviation) The second potentiometer sets the TX VF line input level. The transmitter modulating audio for this test is connected to the TX VF input. This input is located on the rear of the MX800, on the Line I/O connector pin 9 of the DB15F connector. (Refer section 5.1.
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5.l.l2 RX Line Output Level Adjustment The fourth potentiometer sets the RX Line output level. Procedure i) Disable the repeater (switch SW4/DIP2 OFF). ii) Using a 600ohm termination monitor RX line output level. Tl•is output is located on the rear of the MX800, on the Line I/O connector pin 9 of the DBI 5F. iii) Set the receiver modulation frequency to I kHz and the FM deviation to nominal for the particular RF receive frequency of the test channel.
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§ Force the mute open using the Remote Screen in MXTOOLS. § Inject the correct RF frequency into the receiver for the test channel. § Set the receiver modulation frequency to I kHz at nominal deviation. § Alter the amplitude of the RF signal until the RX audio has an 8dB SINAD. § Set the mute back to normal using the Remote Screen in MXTOOLS. § Adjust the mute level potentiometer, RV6, until the mute opens then wind it back until it just closes. 5.2.
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tuned for the band to be tested. ¯ Connect Exciter to working Micro Controller via 16-way ribbon cable. ¯ Disconnect Exciter RF drive output CN 1 from PA. Procedure: 1. Switch DC power on and check that the output voltage on pin 1 of IC5 is 5V +/- 0.2V and that the output voltage on pin 1 of IC3 and IC8 is 8V +/-0.2V. Assert PTT and check that the 8V is switched through to SKU-3. 2. Check reference oscillator signal on center pin pad of CN3 is > 3V pk-pk. 3. Select mid channel.
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§ § Oscilloscope +13.8VDC power supply Preliminaries: ¯ Program upper, middle and lower frequencies of band (refer section 5.4 for band split details) into 3 channels in MXTOOLS channel screen ( Note that 'Continuous Update Enabled' on the MXTOOLS channel screen should be ticked for these tests). ¯ Remove top cover from Receiver module under test and fit known working VCO tuned for the band to be tested ( refer section 4.5). ¯ Connect Receiver to working Micro Controller via 16-way ribbon cable.
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screw and C60 is not fitted). Connect a comms test set to this lead and check that RF local oscillator power is +17dBm +/- 2dB. Measure local oscillator frequency, this should be Frx-90MHz(45 MHz for A2,A3 modules). Using a non metallic trimmer tool carefully adjust the TCXO (X2) frequency until the correct frequency is obtained. Remove the test lead and solder S3 back in position. 2. Place the high frequency pick up loop in close proximity.
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from MX800. Connect PA RF output to RS power meter and PA RF input (CNi) to RF signal generator. 2. Set signal generator to center frequency of PA under test and reduce RF drive level (from signal generator) to zero. Switch DC power on and check that supply is present on L9. Assert PTT (check that no output RF power is emitted from the PA) check that the 13.
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Procedure: I. Select mid channel. Connect SKU from exciter to VCO, switch DC power on, assert PTY and measure RF output power on VCO SKT-6. This should be 0dBm to +3dBm. Measure RF output level on SKU-1. This should be 0dBm to +3dBm (Note that if SKU-1 is disconnected from the exciter the loop will lose lock). Reconnect SKT and SKU to exciter. 2. Select lower channel. Assert PTT and check that loop is locked. Adjust trim cap CT1 on VCO for 3VDC (2VDC for N2 band) on SKT- 1. Select upper channel.