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.
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Ramsey Publication No. MCB1 Price $5.00 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 ..........
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.
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.
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.
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 .
CONSTRUCTION OF THE CB-1 VOICE RECORDER The first thing we will do is locate the two PC boards used with this kit, and then find where we will be starting construction. The smaller board, with the 3/8" hole in it, is called the display board. We'll construct it last since it has finer traces, and a little practice on the bigger board will be of help. The larger logic board is where we'll be starting. If the two boards have not been separated already, you will want to separate them before you start.
r 10. Install C19, .01uF disc capacitor (marked .01 or 103 or 10nF). This capacitor prevents DC voltage on the microphone from entering the ISD1020 IC chip. A capacitor allows AC signals such as voice to pass through, but blocks any DC voltage. r 11. Install jumper JMP7. Use a scrap piece of clipped off component lead wire bent into a wire staple shape. Jumpers act as electronic "bridges" carrying signals over other circuit traces on the circuit board. r 12.
switches. Switch bounce is literally mechanical bounce that results from the pressing of the switch. High speed electronic circuits will see this bouncing and will respond as though the switch was depressed many times very quickly. Typical switch bounce is in the 10 to 20 millisecond range (that's 10 to 20 thousandths of a second!). r 22. Install R11, 10K ohm resistor (brown-black-orange). r 23. Install R1, 10K ohm resistor (brown-black-orange). r 24. Install C1, .01uF disc capacitor (marked .
The circuitry you're working on now is the display driving circuit. When the input to the circuit is low (near ground or zero volts), Q6 is off, which turns Q4 on, turning on only the address display. When the input is high (near +5V), Q5 turns on and only the mode display is on. When the circuit is operating, this switching is fast enough that it can't be seen by the eye (about 100 to 1000 times a second).
r 49. Install R7, 2.2K ohm resistor (red-red-red). This part plays a role in the keying of an attached radio. Depending on what type of microphone your radio requires depends on whether or not this resistor is used. In all of the Ramsey FX series transceivers and most handhelds, the resistor is required. We'll look at this part later when we get to the MICROPHONE CONSIDERATIONS section. r 50. Install R17, 2.2K ohm resistor (red-red-red). r 51. Install R20, 10K ohm resistor (brown-black-orange). r 52.
Take a break and get your soldering skills saved up for the construction of the display board. Locate the small display board and install the following parts: r 65. Install U1, a 4511, BCD to 7 segment display driver IC. Do not use a socket for this part since it must sit below the LED displays. Observe correct orientation. r 66. Install jumper JMP5. r 67. Install DS2, one of the LED displays. Notice the decimal point faces the lower right of the board. This is where the soldering becomes difficult.
from the backside of the display board through the 3/8" hole. The tab on the potentiometer must be removed. Attach the mounting hardware securely. r 77. Here's the tricky part of assembly - mounting the display board to the main board. The most important part of this step is achieving a nice right angle between the display board and the main board. Align the main board with the display board and notice how the pads on each board line up with each other.
labeled MIC1 near VR1. NOTE: In steps 84 through 88, connections CCW, SW-B, W, CW and SWA are labeled on your board. These connections all refer to POT1, the volume control. Please identify these connections using the parts layout diagram on page 21 or using the picture at the right. r 84.
r 88. Connect a 7" piece of black wire from the pin labeled SW-A on the potentiometer to the hole labeled SW-A on the main board near VR1. Solder the wire in place. Finally! You've just completed the assembly of your CB-1 and now you're almost ready for a test run. First go over all connections and wiring to check for any mistakes. You sure wouldn't want to try out your kit in a hurry and damage something that may not be easy to repair.
r 6. Switch the voice recorder to mode 6 and address 1. Press and hold down the start button while talking into the microphone. Release the start button when you are done recording. Switch back to mode 1 and press the start button. Your message should be audible at the speaker. The decimal points of the displays should light as long as you hold the start button. r 7.
PROBLEM: A segment or two is out on one or both displays, or odd numbers are displayed. SOLUTION: These problems most often occur right behind the displays, where solder bridges and cold solder joints form. Don’t worry; even some experienced solderers still have trouble with these. PROBLEM: Decimal point is always on.
CB-1 • 19
MICROPHONE CONSIDERATIONS The CB-1 has a built-in miniature electret condenser microphone which is ideal for stand alone operation. If you would like to use an external microphone, it can be connected to the "MIC IN" jack, J3. Any sort of microphone may be used. In addition, the CB-1 is designed to be used with push-to-talk (PTT) microphones of the Icom/Yaesu/Radio Shack variety. If one of these microphones is used, you may use the PTT button on the mike to automatically start and stop the recorder.
CB-1 PARTS LAYOUT DIAGRAM CB-1 • 21
The Ramsey Kit Warranty Please read carefully BEFORE calling or writing in about your kit. Most problems can be solved without contacting the factory. Notice that this is not a "fine print" warranty. We want you to understand your rights and ours too! All Ramsey kits will work if assembled properly. The very fact that your kit includes this new manual is your assurance that a team of knowledgeable people have field-tested several "copies" of this kit straight from the Ramsey Inventory.
CB-1 "CHATTERBOX" VOICE RECORDER Quick Reference Page Guide Introduction to the CB-1 ................... How it works ..................................... Parts list ............................................ CB-1 Assembly instructions.............. Initial testing...................................... Troubleshooting ................................ Using the CB-1 ................................. Microphone considerations .............. Parts Layout diagram ....................... Schematic diagram ...
