Ritron RIT17-445 用户手册
MAINTENANCE INFORMATION
Surface Mount Repair
RITRON surface mount products require special equipment and servicing techniques. Improper servicing
techniques can cause permanent damage to the printed circuit board and/or components, which is not covered by
RITRON’s warranty. If you are not completely familiar with surface mounted component repair techniques, RITRON
recommends that you defer repair to qualified service personnel.
Precautions for Handling CMOS Devices
RITRON’s warranty. If you are not completely familiar with surface mounted component repair techniques, RITRON
recommends that you defer repair to qualified service personnel.
Precautions for Handling CMOS Devices
This radio contains complementary metal-oxide semiconductor (CMOS) devices, which require special handling
techniques. CMOS circuits are susceptible to damage by electrostatic or high voltage charges. Damage can be latent,
with no failure appearing until weeks or months later. For this reason, take special precautions any time you
disassemble the radio. Follow the precautions below, which are even more critical in low humidity environments.
1) Storage/transport - CMOS devices that will be stored or transported must be placed in conductive material so that
with no failure appearing until weeks or months later. For this reason, take special precautions any time you
disassemble the radio. Follow the precautions below, which are even more critical in low humidity environments.
1) Storage/transport - CMOS devices that will be stored or transported must be placed in conductive material so that
all exposed leads are shorted together. CMOS devices must not be inserted into conventional plastic “snow” or
plastic trays of the type that are used for other semiconductors.
plastic trays of the type that are used for other semiconductors.
2) Grounding - All CMOS devices must be placed on a grounded bench surface. The technician that will work on the
radio/CMOS circuit must be grounded before handling the radio. Normally, the technician wears a conductive wrist
strap in series with a 100K Ohm resistor to ground.
strap in series with a 100K Ohm resistor to ground.
3) Clothing - Do not wear nylon clothing while handling CMOS circuits.
4) Power off - Remove power before connecting, removing or soldering a PC board that contains CMOS devices.
5) Power/voltage transients - Do not insert or remove CMOS devices with power applied. Check all power supplies to
4) Power off - Remove power before connecting, removing or soldering a PC board that contains CMOS devices.
5) Power/voltage transients - Do not insert or remove CMOS devices with power applied. Check all power supplies to
be used for testing CMOS devices, making sure that no voltage transients are present.
6) Soldering - Use a grounded soldering iron for soldering CMOS circuitry.
7) Lead-straightening tools - When straightening CMOS leads, provide ground straps for the tool used.
Synthesizer and RF Power Amplifier Shield
7) Lead-straightening tools - When straightening CMOS leads, provide ground straps for the tool used.
Synthesizer and RF Power Amplifier Shield
The synthesizer or power amplifier shield should not be removed unless a component must be replaced. This
shield is soldered to the main PC board. Sucking or wicking the solder up around the perimeter can remove the shield. If
this should prove difficult a side cutter can cut the top off after which the walls can be removed. A replacement shield
will then be needed and is available from RITRON.
this should prove difficult a side cutter can cut the top off after which the walls can be removed. A replacement shield
will then be needed and is available from RITRON.
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