User Manual
Table Of Contents
- 1GENERAL
- 1.1Introduction
- 1.2Interim Operation
- 1.3Manual Organization
- 1.4UT-4R400 Transmitter Family Models
- 1.5Performance Specifications
- 1.5.1General
- 1.5.2Audio Specifications
- 1.5.3Physical Specifications
- 2THEORY OF OPERATION
- 2.1General
- 2.2Power Supply
- 2.3High Speed Serial Interconnect
- 2.4Audio Circuits
- 2.5PTT Circuitry
- 2.6Microprocessor Board
- 2.7Channel and Bank Selection
- 2.7.1Channel Select Line Mapping
- 2.8Jumper Functions and standard configuration
- 2.9Hang Timer Selection
- 2.10Kerchunk noise selection
- 2.11Test Points
- 2.12Connector Pinouts
- 2.12.1Connector J9
- 2.12.2Connector P1
- 2.13Transmitter Programming
- 2.13.1Transmitter Wide Options
- 2.13.1.1Frequency Band
- 2.13.1.2Source ID
- 2.13.1.3Secure Hardware Equipped
- 2.13.1.4Timeout Options
- 2.13.2Channel Wide Settings
- 2.13.2.1Channel Name
- 2.13.2.2Frequency
- 2.13.2.3Analog Bandwidth
- 2.13.2.4Deviation
- 2.13.2.5Channel Type
- 2.13.2.6Audio Pre-emphasis
- 2.13.2.7Timeout Value
- 2.13.2.8Project 25 Squelch Settings: Network Access Code (NAC)
- 2.13.2.9Project 25 Squelch Settings: Talk Group ID (TGID)
- 2.13.2.10Analog Signaling Settings: Signaling
- 2.13.2.11Analog Signaling Settings: CTCSS Tone
- 2.13.2.12Analog Signaling Settings: Reverse Burst
- 2.13.2.13Analog Signaling Settings: DCS Code
- 2.13.2.14Analog Signaling Settings: Turnoff Code
- 2.13.2.15Analog Squelch Settings: Invert DCS
- 3Transmitter Assembly and Adjustment
- 3.1Frequency Change
- 3.2Minor Frequency Change
- 3.3Major Frequency Change
- 3.4Digital Signal Processor Board Alignment
- 3.4.1Radio Service Software
- 3.4.2Radio Programming Interface Module Interconnection
- 3.4.3Reference Oscillator Adjustment
- 3.4.4Transmitter Deviation Balance Adjustment
- 3.4.5Transmitter Deviation Limit Adjustment
- 3.4.6Audio Level Alignment
- 3.4.7Amplifier Alignment
- 3.5Recommended Test Equipment List
- 3.6Repair Note
- 3.7Printed Circuit board Numbering Convention
- 4Repeater System Configuration
- 4.1Interim Repeater
- 4.1.1Repeater Interconnect Cable Pinout
- 4.2Project 25 Compliant Repeater
- 4.3Repeater System Troubleshooting
- 5ILLUSTRATIONS
- 5.1Digital Repeater Transmitter Front Panel
- 5.2Digital Repeater Transmitter Exploded View
- 5.3Digital Repeater Transmitter Block Diagram (Interim Mode)
- 5.4Digital Repeater Transmitter Schematic Diagram
- 5.5Digital Repeater Transmitter Main Board Component Layout (Bottom)
- 5.6Digital Repeater Transmitter Main Board Component Layout (Top)
- 5.7Digital Repeater Microprocessor Board Component Layout (Bottom)
- 5.8Digital Repeater Microprocessor Board Component Layout (Top)
- 6PARTS LIST
- 6.1Digital Repeater Transmitter Main Board Parts List
- 6.1.1Digital Repeater Transmitter Main Board Electrical Parts List
- 6.1.2Digital Repeater Transmitter Main Board Mechanical Parts List
- 6.2Digital Repeater Microprocessor Board Parts List
- 6.2.1Digital Repeater Microprocessor Board Electrical Parts List
- 6.2.2Digital Transmitter Additional PCBs
- 7REVISION HISTORY
DE
DANIELS
ELECTRONICS
UT-4R400 UHF Project 25
Digital
Transmitter
Instruction
Manual
4-3
separate
control of their
channel
select
lines, so changing
receiver
channels does not
affect
the
transmitter
channel.
Q: Why is the
transmitter
staying on after the
receiver
signal is
removed?
A: The
transmitter
has a hang
timer
that keeps it keyed after the
receiver
signal disappears. This
can be used to keep a chain of
repeate
rs up between transmissions. The delay is
adjustable
from 0
to 3.75
seconds.
Q: What’s that noise at the end of a transmission?
A: The
transmitter
can insert an
audible
“kerchunk”
at the end of a
repeater
transmission. In
Project 25
digital
mode, this
simulates
the
effect
of the squelch noise, which is heard at the end of
an analog
repeater
transmission. In analog systems, the squelch noise is the sound of the
receiver’s
IF noise before it squelches. This is often useful as a
confirmation
to
repeater
users that
they have
“hit”
the repeater. In Project 25
Digital
mode, no noise is heard at the end of a
transmission due to the
all-digital
nature of the system, so an
artificial
noise is added to serve the
same
purpose.
There is a jumper on the
transmit
ter’s microprocessor board to disable the
kerchunk noise.
Q: Why is the Radio Service Software
failing
partway through a read or write of the
receiver?
A: If the
receiver
is squelching and unsquelching
repeatedly
during the read or write operation, the
communications
bus may be too congested. Try changing channels on the receiver, or
disconnect
the RF signal source from the
receiver
during the read or write operation.
Q: Why does the
transmitter
not
transmit
with the
correct
TGID or NAC, or in the wrong mode?
A: In a
typical
repeater, if the
received
signal is digital, the
transmitter
will be keyed from a bank B
channel, NOT from bank A, even though the
receiver
may be
receiving
on a bank A channel.
Make
sure that for each
transmit
channel
number, both the A and B bank are
programmed
with
analog
information
and Project 25 information, respectively.