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CB-1 

 6 

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.

Summary of Contents for CB1 CHATTERBOX

Page 1: ...ed 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 rad...

Page 2: ...R 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...

Page 3: ...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 KIT ASSEMBLY AND INSTRUCTIO...

Page 4: ...imply 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 v...

Page 5: ...an 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 volum...

Page 6: ...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...

Page 7: ...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 r...

Page 8: ...three pins r 2 Install voltage regulator VR1 7805 Observe correct placement of the metal tab Mount it so the lettering on the case is facing the edge of the board The 7805 provides a stable source of...

Page 9: ...side of the board to verify that all 28 pins are sticking through the board before soldering After you check that all 28 pins are properly in place solder all pins Be very careful in soldering since s...

Page 10: ...solder bridges when finished soldering This is where the microcontroller chip the IC with the sticker on top or marked XC705K1P is to be inserted Insert U3 into the socket being careful of bent under...

Page 11: ...1 2N3904 transistor Watch the positioning of the flat side r 42 Install Q2 2N3904 transistor watching the positioning of the flat side Transistors Q1 and Q2 are used to key an external radio r 43 Inst...

Page 12: ...orrect installation r 55 Install C7 10uF electrolytic capacitor Pay attention to polarity This is a DC blocking capacitor for the audio out of the ISD chip r 56 Install U2 LM380 audio amplifier IC Obs...

Page 13: ...1 use the same care that you used for installing DS2 r 70 Install R2 75 ohm resistor violet green black This is another current limiting resistor r 71 Install S2 one of the mini push button switches I...

Page 14: ...two joints check again to make sure the boards are square If all checks OK continue on to the rest of the solder pads checking for solder bridges as you go The more area that is connected with solder...

Page 15: ...te or other color wire from the pin on the potentiometer labeled SW B to the hole on the main board near VR1 labeled SW B Solder the wire in place r 86 Connect a 5 piece of black wire from the pin on...

Page 16: ...oldered in the correct places r 2 Make sure the power switch is turned off Plug in the 12VDC supply to J4 Make sure the center pin is the positive terminal and the outside of the jack is ground or neg...

Page 17: ...ibed go to the trouble shooting section of the manual to determine how to resolve the problem TROUBLESHOOTING TIPS PROBLEM Neither display lights when powered up and there is no sound SOLUTION Use a m...

Page 18: ...mike but allows audio to pass PROBLEM One or more switches won t work but everything else is OK SOLUTION Check the junction between your main board and the display board Many problems can arise here U...

Page 19: ...CB 1 19...

Page 20: ...you must understand the pins of the DIN connector on the rear of the unit 5 Pin DIN Jack Connections Pin 1 Audio output to radio mic in Pin 2 Ground Pin 3 Push to talk open collector Pin 4 Radio speak...

Page 21: ...CB 1 21 CB 1 PARTS LAYOUT DIAGRAM...

Page 22: ...be assured that the 1K ohm resistors are actually the missing 10 K parts Hum m m I guess the red band really does look orange Ramsey Electronics project kits are packed with pride in the USA If you b...

Page 23: ...CB 1 Assembly and Instruction manual for RAMSEY MODEL NO CB 1 RAMSEY ELECTRONICS INC 793 Canning Parkway Victor New York 14564 Phone 716 924 4560 Fax 716 924 4555 REQUIRED TOOLS Soldering Iron Radio S...

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