Technical Manual
Table Of Contents
- Vocoder and Controller Boards Detailed Theory of Operation
- Introduction to This Section
- General
- Vocoder Board
- Controller Board
- Switching Regulator
- RX Signal Path
- TX Signal Path
- Controller Bootstrap and Asynchronous Buses
- Vocoder Bootstrap
- SPI Bus Interface
- Universal Connector and Option Selects
- Keypad and Display Module
- Controls and Control Top Flex
- Controller Memory Map
- Vocoder Memory Map
- MCU System Clock
- DSP System Clock
- Radio Power-Up/ Power-Down Sequence
- Notes
- Secure Modules
- Disassembly/Reassembly Procedures
- Troubleshooting Procedures
- Troubleshooting Charts
- Troubleshooting Waveforms
- Troubleshooting Diagrams
8-8
Conducting the Test 1. Remove the vacuum test port (see Section 13, page 72, item 62)
using a 7/64” Allen key. Remove the O-Ring; item 63.
2. Screw the adapter (with gasket) into the tapped hole in the casting.
3. Attach one end of the pressure hose to the adapter and the other
end to the pressure pump.
4. Cover the vent port seal (65) and label (66) on the back of the
casting with your thumb. This will prevent air from going
through the seal. Keep the vent port covered with your thumb
until the test is complete (through step 8).
5. Operate the pump until the gauge reads approximately 1 psig.
Pressure any greater than 1 psig may push air around the
main seal.
6. Maintain the pressure at 1 psig and submerse the radio into a
water-filled container. Keep the vent port covered with your
thumb while the radio is submersed.
7. Watch for any continuous series of bubbles. A stream of bubbles
indicates a sign of leakage.
NOTE: Some air entrapment may cause the accumulation
of bubbles, especially in the grille area, but the
bubbles should not be continuous.
8. Note all of the seal areas that show signs of leakage. Pinpoint the
problem(s) to one (or more) of the following areas:
• housing
• antenna bushing seal
• controls seal
• frequency switch, toggle, and on/off/volume control switch
• main seal
• battery contact and battery contact seal
• keypad
9. Remove the radio from the water container, remove your thumb
from the vent port seal, and dry the radio thoroughly. Be
especially careful to dry the area around the main seal to prevent
contamination of the internal electronics while the unit is open.
To avoid equipment damage, keep the area around the port seal dry by
ensuring that there is no water around the casting’s vacuum port.
10. Remove the adapter and pressure hose added in steps 1 and 2,
above.
11. Install the o-ring and the vacuum test port plug. Torque the plug
to 6 in-lb.
12. Inspect the vent port seal (65) to ensure that the seal behind the
label’s (66) two slots has not been punctured. If it has been
punctured, the seal and the label must be replaced.
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C a u t i o n