Technical Manual
Table Of Contents
- 1. Introduction
- 2. Hardware
- 3. The A431 Radio Module
- 3.1. About the A431 Radio Module
- 3.2. Functional description
- 3.3. Manufacturing Issues
- 3.3.1. Marking and labeling issues
- 3.3.2. Alignment Range and Switching Range
- 3.3.3. Tuning Procedure
- 3.3.4. Setting Up the Default Parameters
- 3.3.5. Definitions
- 3.3.6. Test Equipment Settings
- 3.3.7. Trimming Elements
- 3.3.8. Adjusting the Receiver Front End
- 3.3.9. Adjusting the VCOs
- 3.3.10. Adjusting the Crystal Reference
- 3.3.11. Checking the Receiver Parameters
- 3.3.12. Checking the Transmitter Parameters
- 3.3.13. Data Transfer Check
- 3.4. PCB Parts Placement
- 3.6. Frequency Reference Specifications
- 3.7. A431 Module’s Photographs
- 4. Software
36
The A431 Radio Module
3. Switch the Service Monitor to TX TEST mode, on the appropriate frequency
(430 / 440 / 450 or 460 MHz respectively). You should see the following
parameters on the Service Monitor readout:
a. Carrier: 430000000 ± 200 Hz (or 440000000 / 450000000 / 460000000
respectively)
b. Output Power: 26.5 dBm (+ 0.5 dBm / - 1 dBm)
c. Frequency Deviation: ±2.0 kHz (±0.2 kHz)
4. Switch the unit to stand-by by pressing the Enter key.
For item 3.a above, adjust R75 (see Figure 20). For item 3.b, issue the command
PWR at the terminal and use the D (down) and U (up) keys until the required value
is reached. Finally, for item 3.c, issue the command BW at the terminal and again
use the D and U keys to reach the required value.
3.3.13. Data Transfer Check
The last check is a radio data transfer. In order to perform it, at least a base station
(model A730SD) or another remote station (model A733) must be installed and op-
erated on the same test frequency, in the near vicinity (no more than 30 m).
Note: The base or remote station used for this test must be operated with a fictive
antenna (a 50
Ω
resistor).
To perform the test, enter the command B at the terminal prompt: the base and/or
remote station must answer with the RF in and out values. If an answer is not re-
ceived after several seconds, retry the command. If an answer is still not received,
then use a scope on TP1 on the A733MB board (the Text Fixture) to verify that the
digital data is present (on receive). In addition, a radio receiver tuned on the oper-
ating frequency can also supply a rough indication of whether the receiver or the
transmitter is defective.