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©1999 Hamtronics, Inc.; Hilton NY; USA.  All rights reserved.  Hamtronics is a registered trademark.    Revised: 1/28/00

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GENERAL INFORMATION.

Functional Description.

The DVR-3 is a versatile pc board

module, which is designed primarily
as a voice id'er and message re-
corder for the REP-200T Repeater.
It is a special version of the general

purpose DVR-1 module.  The differ-
ence is that the DVR-3 substitutes
direct control interfaces with the
COR-5 Control Board for the general
purpose timer and logic circuits on
the DVR-1, and the DVR-3 uses
audio off the air for recording in-
stead of a microphone.

The  DVR-3 module is based on

the ISD-1020A chip, using direct
analog eeprom technology.  The re-
cording is good speech quality,
equivalent to what you would expect
using a cassette tape recorder.  The
solid-state recording lasts ten years
or more and requires no battery
backup.

Use of the DVR-3 requires firm-

ware version 2.06 or later in the
REP-200 Repeater.  This includes all
repeaters manufactured after De-
cember 1993.  Older repeaters can
be retrofitted by replacing the
eprom; no hardware changes to the
control board are required.

The COR-5 Controller provides

the means to enable either the
voice id or conventional cw id, and it
provides the triggering signal for the
DVR-3 module and the necessary
timing to ensure that the id occurs
at the proper time and that the
transmitter is keyed each time that
the id message is played back.  It
also allows the message to be re-
corded and played back through
dtmf commands.

Enhancements.

The 20 seconds of recording time

normally is accessed all as one unit.
However, with the addition of some
external addressing switches, the
20 second capacity can be broken
up, any way you like, into multiple
messages.  Although, switching cir-
cuitry to do this is not provided, the
address line connections are pr o-
vided, and information on how to
add switches to do your own en-
hancements is given later in the
manual.

Other enhancements may be

added to suit your application.  With
a few changes, you can make the
message repeat periodically or loop
continuously.

Recording Quality.

The ISD-1020A is an amazing

new ic which implements an entire
digital voice recording and playback
system in one chip.  This brings real
voice to the radio community at a
previously unheard-of low price.

HAMTRONICS

HAMTRONICS®®  DVR-3 DIGITAL VOICE RECORDER

  DVR-3 DIGITAL VOICE RECORDER

ASSEMBLY, INSTALLATION, AND OPERATION

ASSEMBLY, INSTALLATION, AND OPERATION

TABLE OF CONTENTS

GENERAL INFORMATION.............................................................. 1

Functional Description. ............................................................. 1
Enhancements. ........................................................................ 1
Recording Quality. .................................................................... 1

ASSEMBLY. ................................................................................. 2

Construction Methods. .............................................................. 2
Precautions.............................................................................. 2
Assembly Procedure................................................................. 2

INSTALLATION. ............................................................................ 2

Mounting.................................................................................. 2
Wiring. .................................................................................... 3

OPERATION. ................................................................................ 3

General.................................................................................... 3
Recording a Message. .............................................................. 3
Voice ID Operation. .................................................................. 4
Message Playback for Testing. .................................................. 4
Playback by DTMF Request. ..................................................... 4

ENHANCEMENTS. ........................................................................ 4

General.................................................................................... 4
Changing Tone......................................................................... 4
Addressing More Than One Message. ........................................ 4
Multiple Messages..................................................................... 5
Remote Control of Multiple Messages. ........................................ 5

THEORY OF OPERATION. ............................................................. 5

General.................................................................................... 5
Recording Technology. ............................................................. 6
Audio Recording Circuits. ......................................................... 6
Audio Playback Circuits. ........................................................... 6
U1 Control Circuits. .................................................................. 6
S2 Record Switch Circuit. ......................................................... 6
Q1 Playback Latch Circuit. ........................................................ 6
Remote Control Circuits. ........................................................... 7
Q2/Q3 ID Key Circuit. ............................................................... 7
Addressing............................................................................... 7
Power Distribution. ................................................................... 7

TROUBLESHOOTING. ................................................................... 7

General.................................................................................... 7
Digital Recorder U1. ................................................................. 7
Switching Transistors. ............................................................... 7
Power Supply Circuit. ............................................................... 8

PARTS LIST ................................................................................. 9
COMPONENT LOCATION DIAGRAM.............................................. 9
SCHEMATIC DIAGRAM............................................................... 10

Summary of Contents for DVR-3

Page 1: ...essed all as one unit However with the addition of some external addressing switches the 20 second capacity can be broken up any way you like into multiple messages Although switching cir cuitry to do...

Page 2: ...parts are correct before sol dering Traces are close together so use a fine tip on the soldering iron All parts should be installed flush with the board Assembly Procedure Install and solder the part...

Page 3: ...the wrong point if the resistor was inad vertently reversed when the COR 5 board was assembled Wrap the wire around the resistor lead and tack solder b Connect the brown playback control wire to the...

Page 4: ...tal recording time is 20 seconds When you send the Record Voice Msg command the yellow TimeOut led will illuminate to indicate the DVR 3 is ready to record This led is used for convenience it does not...

Page 5: ...ssed Because we are addressing in one second incre ments the highest practical ad dress is 19 seconds We mentioned earlier that there are other operational modes besides the addressing mode These are...

Page 6: ...ace and internal precision reference clock This system uses eeprom technology to directly record analog signals so no d a and a d converters are required The 1020A ic uses a sampling rate of 6 4 kHz f...

Page 7: ...le line is what actually starts each record or play back cycle It is held low to make the chip run The EOM line puts out a low sig nal under two conditions First when the playback mode reaches the end...

Page 8: ...he regulated 5Vdc power bus on the COR 5 board Electrolytic capacitor C13 provides a low ac im pedance for the 5V bus on the DVR 3 board There are two separate 5Vdc busses on the DVR 3 board and separ...

Page 9: ...output on the audio output pins 14 15 during record Q1 does not latch on as it does in playback mode Switching transistors Q4 and Q5 act as a buffer for the Record Con trol input from the Time Out le...

Page 10: ...1 C3 Z1 CR2 S1 S2 C5 R2 R1 Q1 R3 C1 C6 R7 C9 C8 C4 C2 R4 R5 R9 C10 R10 C12 _ R11 Q2 COMPONENT LOCATION DIAGRAM DVR 3 DIGITAL VOICE RECORDER MODULE E6 E5 BREAK TRACE TO DISCONNECT GND TO MIC REF PAD R1...

Page 11: ...AF INPUT REF 17 18 AF OUT AF OUT 14 15 X DIGITAL RECORDER N C Q1 E3 KEY Q2 SWITCH _ AGC 19 R11 R12 Z1 C3 C4 C5 R7 C6 C8 C9 E5 E6 C11 R8 R9 R10 C10 C12 C2 R4 47K R5 47K CR2 C1 R1 R2 RECORD DVR 3 DIGITA...

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