Ramsey Electronics CB1 CHATTERBOX User Manual

CB1 CHATTERBOX
VOICE RECORDER

Ramsey Electronics Model No. CB1

Getting tired of repeating yourself? Find yourself saying the
same thing over and over? Here's the answer to your prayers!
This kit will repeat your voice with amazing clarity over and
over, without ever getting tired, in a number of different ways!
Not only that, it preserves your voice even when the power is
turned off.

• 20 seconds of recording time available in five, four second

messages. Messages can be combined for longer record and
playback times.

• Loud 2 Watt audio output.

• Very clean, low noise “DAST” storage technology provides
excellent audio quality.

• Seven modes of operation available. Even interfaces to radios
and computers too!

• Fully microprocessor controlled for easy use, no diodes to add ­no dip switches to set. Easy and fun to use!

• LED displays show addresses and modes quickly, no guesswork.

• Compatible with most transceivers and works with most radio
mikes. It will even key your radio with your message.

• Can be used for: memos, HAM contesting, real estate sales,
leaving the kids messages, CB radio...possibilities are unlimited!

CB-1 • 1

RAMSEY TRANSMITTER KITS

· FM100 Professional FM Stereo Transmitter

· FM25 Synthesized Stereo Transmitter

·AM1, AM25 AM Transmitters

· TV6 Television Transmitter

RAMSEY RECEIVER KITS

· FR1 FM Broadcast Receiver

· AR1 Aircraft Band Receiver

· SR2 Shortwave Receiver

· AA7 Active Antenna

· SC1 Shortwave Converter

RAMSEY HOBBY KITS

· SG7 Personal Speed Radar

· SS70A Speech Scrambler

· ECG1 Heart Monitor

· WCT20 Wizard Cable Tracer

· PG13 Plasma Generator

· LABC1 Lead Acid Battery Charger

RAMSEY AMATEUR RADIO KITS

· FX146 VHF Transceivers

· HR Series HF All Mode Receivers

· QRP Series HF CW Transmitters

· CW700 Micro Memory CW Keyer

· CPO3 Code Practice Oscillator

· Packet Computer Interfaces

· QRP Power Amplifiers

RAMSEY MINI-KITS
Many other kits are available for hobby, school, Scouts and just plain FUN.
New kits are always under development. Write or call for our free Ramsey
catalog.

CB-1 CHATTERBOX KIT INSTRUCTION MANUAL

Ramsey Electronics publication No. MCB-1 Revision 2.1a

First printing: April 1994

COPYRIGHT 1994 by Ramsey Electronics, Inc. 793 Canning Parkway, Victor, New York

14564. All rights reserved. No portion of this publication may be copied or duplicated without the

written permission of Ramsey Electronics, Inc. Printed in the United States of America.

CB-1 • 2

Ramsey Publication No. MCB1

KIT ASSEMBLY

AND INSTRUCTION MANUAL FOR

CB1 CHATTERBOX
RECORDER KIT

TABLE OF CONTENTS

Introduction to the CB-1 ................ 4

How it works .................................. 5

Parts list ........................................ 7

CB-1 Assembly instructions .......... 8

Initial testing ................................ 17

Troubleshooting ........................... 18

Using the CB-1 ............................. 19

Microphone considerations .......... 20

Parts Layout diagram .................. 21

Schematic diagram ..................... 22

Price $5.00

RAMSEY ELECTRONICS, INC.

793 Canning Parkway

Victor, New York 14564

Phone [phone]

Fax [phone]

www,ramseykits.com

CB-1 • 3

CB-1 CHATTERBOX VOICE RECORDER FEATURES

• LED display for mode and address

• Up to five separate four second addresses can be accessed

• Easy to use microprocessor control

• Seven modes available:

Mode 1: Play selected message once.
Mode 2: Play through messages until button is released.
Mode 3: Play selected message over and over while start button is
depressed.
Mode 4: Play through all of memory starting at selected address.
Mode 5: Play one message upon release of the button.
Mode 6: Record until the button is released.
Mode 7: Disable mode.

• 12VDC operation

• Loud 2 Watt audio output

• Designed to operate with a radio transceiver or stand alone

• Will even appropriately key your radio to output a message after each

transmission

• Ideal for contests, repeaters, CB radio or any other application that

requires repetitive speech or sounds

INTRODUCTION TO THE RAMSEY CB-1 VOICE RECORDER

We're sure you've found that it gets tiring repeating what you have just said
over and over again, whether you are contesting, or just simply using your
radio a lot. This kit can take care of the tiresome tasks such as saying "Over
and out", a call sign, CQ, your QTH or whatever. Not only is this kit useful for
repeating messages, but it is very easy to record with also. You simply select
the record mode, press a button, and it instantly records sound through the
built-in microphone. If desired, you may connect up an external microphone
of your choice. Since this circuit records electronically, there is no rewinding
or resetting to wait for, everything is near instantaneous. Since the audio
quality of this kit is very good, your listeners will hardly be able to tell the
difference between your original voice and the recorded voice.

Not only will you find this kit very useful, you'll also find it enjoyable to build,
whether you are a beginner or an experienced kit builder.

NOTE TO NEWCOMERS: If you are a first time kit builder you may find this
manual easier to understand than you may have expected. Each part in the
kit is checked off as you go, while a detailed description of each part is given.
If you are to follow each step in the manual in order, and practice good
soldering and kit building skills, the kit is next to fail-safe. If a problem does

CB-1 • 4

occur, the manual will lead you through step by step in the troubleshooting
guide until you find the problem and are able to correct it.

CIRCUIT DESCRIPTION

Most of the difficult work in this circuit is performed by the ISD1020 voice
recorder IC chip (U4) and the MC68HC705 series microprocessor (U3).
These two ICs "talk" (yes, pun intended!) to each other to access the different
addresses, modes, when to start playback and record on U4. Not only does
the microprocessor control this, but it also runs the two displays, scans the
switches, and provides for a user friendly interface - not bad for a little 16 pin
chip.

The pins PA5, PA6, and PA7 of the microprocessor do a number of tasks.
They not only select the address of where playback and record is to be done,
but at the same time drive U1 to display the information of what address and
mode is selected. PB0 selects which display is turned on. The two displays
are not actually on at the same time, but are switched fast enough by the
microprocessor so that they appear to the eye to be on continuously. PA0
through PA2 scan the switches for mode, play, and address. PA3 chip
selects the voice recorder, and through the pulse shaping circuit of Q7, resets
the ISD1020 IC chip.

The SP output of the ISD1020 is taken through volume control, POT1 and
then fed into the audio speaker driver U2 for amplification. Amplifier U2
provides 2 watts of audio output, capable of driving a speaker to excellent
volume. A simple keying detection scheme consisting of Q8, Q9, and
surrounding components allows sensing of an external microphone's push-to
talk switch. This circuitry simulates the pressing of the play button when there
is a resistive loading effect caused by the keying of the mike. The advantage
of this system is that it allows you to use your existing radio microphone to
activate playback and record.

PB1 on the microprocessor is the line that controls the keying of a connected
transceiver. When the voice recorder is activating your transceiver, decimal
points on the display are illuminated to let you know. Transistors Q1 and Q2
are connected as a Darlington pair to key the radio, and R7 is optional for
either a resistive loading type of keying, or a simple pull down scheme. VR1
is a three terminal voltage regulator to provide the +5 volts required by the IC
circuitry and the microprocessor.

CB-1 • 5

RAMSEY "LEARN-AS-YOU-BUILD RECORDER ASSEMBLY STRATEGY"

The CB-1 voice recorder kit includes two PC boards, one being the main
board and the other a display board. They are mounted at a 90 degree angle
to each other so that the display may be easily read from the front of the kit.
It is obvious that if you were to place these boards together before mounting
all of your parts, it would make further assembly very difficult. For this reason
it is advisable to follow the step-by-step instructions in the manual and not
jump ahead.

We'll start building in one corner and work our way across, installing the
lower components up to the taller sized components. This will make our
placing and soldering of components easy. As we go along we'll attempt to
describe the circuit operation and the function of many of the parts.

Be sure to read through all of the steps, and check the boxes as you go to be
sure you didn't miss any important steps. Before you switch on the power in a
hurry to see results, check all diodes, ICs, and capacitors for proper
orientation. Also check the board for any possible solder shorts or cold solder
joints. All of these mistakes could have detrimental effects on your kit - not to
mention your ego!

Kit building tips:

Use a good soldering technique - let your soldering iron tip gently heat the
traces to which you are soldering, heating both wires and pads
simultaneously. Apply the solder on the iron and the pad when the pad is hot
enough to melt the solder. The finished joint should look like a drop of water
on paper, somewhat soaked in.

Mount all parts on the top side of the board. This is the side that has no
traces or pads on it.

IC sockets - A good practice, but not necessary in digital or low frequency
circuits. This prevents the horror of desoldering a bad or incorrectly placed
IC.

Note: Do not use a socket for U1, as this interferes with a front panel if one is
to be used.

Part orientation - All parts in the kit are mounted at 90 degree angles to each
other, meaning that all parts are either parallel or perpendicular to the board.

Part installation - when parts are installed, the part is placed flat to the board,
and the leads are bent on the backside of the board to prevent the part from
falling out before soldering. The part is then soldered securely to the board,
and the remaining lead length is then clipped off.

CB-1 • 6

RAMSEY CB-1 CHATTERBOX PARTS LIST

SEMICONDUCTORS

r 1 ISD1020A sound recorder IC [U4]
r 1 MC68HC705K1 microprocessor IC [U3], 16 pin IC with white sticker
r 1 LM380 2 watt audio amplifier IC chip [U2]
r 1 MC14511 (4511) BCD to 7 segment IC chip [U1]
r 1 7805 5 volt regulator [VR1]
r 7 2N3904 NPN transistor [Q1,2,4,5,6,7,9]
r 1 221334 PNP (2N3906 type) transistor [Q8]
r 1 1N4148 style silicon diode (glass body with black band) [D2]
r 2 7 segment displays [DS1,2]

CAPACITORS

r 7 .01uF disc ceramic (marked .01 or 103 or 10 nF) [C1,5,6,13,17,19,20]
r 4 .1uF disc ceramic (marked .1 or 104) [C4,8,11,18]
r 1 100pF disc ceramic (marked 100 or 101) [C10]
r 2 1uF electrolytic [C9,14]
r 3 10uF electrolytic [C2,7,16]
r 2 220uF electrolytic [C3,15]

RESISTORS

r 1 2 ohm resistor (red-black-gold) [R13]
r 2 75 ohm resistor (violet-green-black) [R2,3]
r 5 1K ohm resistor (brown-black-red) [R4,5,8,24,25]
r 3 2.2K ohm resistor (red-red-red) [R7,17,26]
r 4 4.7K ohm resistor (yellow-violet-red) [R9,10,18,19]
r 9 10K ohm resistor (brown-black-orange) [R1,11,14,15,20,21,22,23]
r 1 470K ohm resistor(yellow-violet-yellow) [R16]
r 1 10K ohm potentiometer (marked 103) [R6]

MISCELLANEOUS

r 1 5-Pin DIN Connector [J1]
r 1 Electret condenser microphone [MK1]
r 1 Power jack [J4]
r 2 Mini jacks [J2,3]
r 1 Switched potentiometer [POT1]
r 3 Push button switches [S1,2,3]
r 16" red hook-up wire
r 16" white hook-up wire (the color of this wire may vary due to supply- use

whatever color is supplied)

r 16" black hook-up wire
r 5" Buss wire (to be used in place of spare leads if they are used up)
r 1 28 pin IC socket
r 1 16 pin IC socket

REQUIRED, NOT SUPPLIED

CB-1 • 7