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GENERAL
RITRON's DR-142 receiver module is designed to operate in the VHF band. Two band splits are
available, 136-156 MHz (low) or 154-174 MHz (high). The unit receives voice through a nominal 1 watt
speaker output. It supports up to 9600 bps 4-level FSK through its auxiliary output port.
Each radio can be “dealer or factory” programmed to contain a unique set of eight operating frequencies
and options. When all three channel select inputs are tied to ground the radio operates on channel 1. The
channel selection is done in a binary manner on the CS2, CS1 and CS0 inputs. Quiet Call (CTCSS) or
Digital Quiet call (DCS) tones can be programmed per channel.
Model Identification
The DR-142 model, serial number and FCC Identification are displayed on a label located on the bottom
of the PCB.
FCC Label
An FCC label must be visible on the unit as installed in its final configuration. If the unit is to be used as
shipped from RITRON, this would be no problem since an FCC label is affixed to the bottom of the PC
board. If the DR-142 is to be installed in an enclosure, the installer must ensure that either the FCC label
on the unit is visible through a door, window or other opening, or add a label to the outside of the
enclosure. If a label is to be added to the outside of the enclosure, the label must be of a type which is
not easily removed or damaged and contains wording: Contains FCC ID: AIERIT17-142R.
Unauthorized Modifications
Note: The manufacturer is not responsible for any radio or TV interference caused by unauthorized
modifications to this equipment. Such modifications could void the user’s authority to operate the
equipment.
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 boards 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 maintenance 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 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.
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.
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.
