CODE PRACTICE OSCILLATOR KIT Ramsey Electronics Model No. CPO3 Ever wanted to hone your code skill but didn't have an easy way to practice? This handy little kit will allow you to tap away anywhere you happen to be! Small enough to fit into your pocket or briefcase, you can take it anywhere. You'll find yourself up to speed in no time! · · · · · Great starter kit Ideal for Boy Scouts Perfect first electronic kit for schools Increase your code speed . . . practice anywhere. Easy one evening assembly CPO3 · 1 PARTIAL LIST OF AVAILABLE KITS RAMSEY TRANSMITTER KITS · FM10A FM Stereo Transmitter · FM25B Synthesized FM Stereo Transmitter · AM25 Synthesized AM Transmitter · AM1 AM Transmitter RAMSEY RECEIVER KITS · FR1 FM Broadcast Receiver · AR1 Aircraft Band Receiver · AA7 Active Antenna · SC1 Shortwave Converter RAMSEY HOBBY KITS · SG7 Personal Speed Radar · SS70 Speech Scrambler · TT1 Telephone Recorder · SP1 Speakerphone · MD3 Microwave Motion Detector · PH10 Peak hold Meter · LC1 Inductance-Capacitance Meter RAMSEY AMATEUR RADIO KITS · DDF1 Doppler Direction Finder Kit · HR Series HF All Mode Receivers · QRP Series HF CW Transmitters · CW7 CW Keyer · 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. CODE PRACTICE OSCILLATOR KIT INSTRUCTION MANUAL Ramsey Electronics publication No. MCPO3 Revision First printing: January 2001 COPYRIGHT 1994 by Ramsey Electronics, Inc. 590 Fishers Station Drive, 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. CPO3 · 2 Ramsey Publication No. MCPO3 Manual Price Only $5.00 INSTRUCTION MANUAL FOR CODE PRACTICE OSCILLATOR KIT TABLE OF CONTENTS Introduction .................................... 4 Circuit Description .......................... 4 Schematic Diagram........................ 5 Parts Layout Diagram .................... 5 Parts List ........................................ 6 Identifying Kit Parts ........................ 7 International Morse Code............... 8 Assembly Instructions .................. 12 Testing ......................................... 14 Conclusion ................................... 14 Ramsey Kit Warranty ................... 15 RAMSEY ELECTRONICS, INC. 590 Fishers Station Drive Victor, New York 14564 Phone (585) 924-4560 Fax (585) 924-4555 www.ramseyelectronics.com CPO3 · 3 INTRODUCTION Morse Code has been used since 1837. It was originally used for telegraph communications and was the first method used for radio communications. For many years, Morse Code was required knowledge for any shipboard radio operator. In 1910, the Titanic was the first ship to use the international distress call SOS. Until recently, code proficiency was required for all amateur radio licensees and was even required by the Boy Scouts. It still is required for the Signaling merit badge. The CPO3 is a fun, educational kit for any skill level builder and can be used to introduce anyone to this historic means of communication. CIRCUIT DESCRIPTION As the key is pressed, providing the circuit a ground path and starting the cycle, two things happen. C1 starts to charge via R1, R3 and R4. At this time the output of pin 3 is high. When the voltage on C1 reaches 2/3 of the supply voltage, the output of pin 3 will go low and pin 7 is grounded, starting the discharge cycle. The capacitor is discharged through R1. When the voltage on C1 reaches 1/3 of the supply voltage, the output at pin 3 goes high and pin 7 is no longer at ground. This starts the charging cycle again. Timing is completely independent of the supply voltage used. It is determined by the values R1, R3, R4 and C1. The formula for the total time (T) of a complete cycle is: T = 0.693[(R3+R4+2R1)C1]. The component values provided allow a range of 1300 Hz to 1700 Hz. The key is attached to pin 1 and provides the kit with a ground connection, completing the circuit and turning the entire unit on. The key is basically an on/off switch. Capacitor C2 filters out noise and R2 is a current limiting resistor for the speaker, SP1. CPO3 · 4 PARTS LAYOUT DIAGRAM CPO3 · 5 PARTS LIST RESISTORS 1 1 1 1 270 ohm resistor [red-violet-brown] (R2) 1K ohm resistor [brown-black-red] (R1) 10K ohm resistor [brown-black-orange] (R3) 5K ohm trim pot [marked 502] (R4) CAPACITORS 1 .1 µF ceramic disc capacitor [marked .1 or 104 or 100 nF] (C1) 1 .01 µF ceramic disc capacitor [marked .01, 103, or 10nF] (C2) SEMICONDUCTORS 1 NE555 timer/oscillator chip (U1) HARDWARE AND MISCELLANEOUS 1 1 1 1 2 2 4 mini speaker (SP1) 9 volt battery snap brass strip #4 flat washer 4-40 x 1/4 machine screws 4-40 kepnuts rubber feet CPO3 · 6 SORTING PARTS AND GETTING READY! Prepare a clear, uncluttered workspace. In addition to room needed for tools and handling the circuit board, allow space for some kind of "parts organizer" that will not be bumped or dropped. This organizer can be a small tray or box. (An egg crate works great!) Refer to the Parts List published in the kit manual. Organize the kit parts according to basic types. Check carefully to make sure a small part did not slip away when opening the kit's packaging. Please make sure that you have sufficient lighting for clear parts identification and accurate circuit soldering. This might seem like gratuitous advice that you did not ask for, but experience has shown that brown, orange, red and silver resistor colors and tiny numbers on capacitors and transistors all start to look the same in dim light after a hard day's work! IDENTIFYING KIT PARTS CERAMIC DISC CAPACITORS It is helpful practice to become as familiar as possible with the various marking codes for ceramic capacitors. The first fact to keep in mind is that there are several accepted methods for marking the value of these capacitors! While resistor color codes have withstood changing times over many decades, the protocols for marking evermore tiny capacitors have many variations! While capacitors also can be color-coded, Ramsey Kits use disc capacitors marked by a number/letter code. The first two digits establish the first two numbers of the value. The third digit is the multiplier. The letter designates the manufacturing 'tolerance"or accuracy for the value printed. Values under 100 picofarads, used widely in our FM and VHF kits, are printed clearly with no need to interpret them further. Small capacitors stamped 4.7, 10, 15, 33, 68 and so forth are 4.7, 10, 15, 33, 68 picofarads respectively! A 100 picofarad capacitor, also commonly used in our kits, can be marked either 100 or 101! If it's marked 100, believe it. If it is marked 101, the value is 10 (first 2 digits) X 10 (3rd digit multiplier) = 100 picofarads! If it is marked 101J, we know that it is made to 5% accuracy, while H signifies 3% and K is 10%. Rule of thumb: If the 3rd digit is a 0, you may assume the value is in picofarads, and you can take the three numbers together as the picofarad value for that capacitor. So, just as in the above example, both "470" and "471" are 470 pf. CPO3 · 7 INTERNATIONAL MORSE CODE CPO3 · 8 CPO3 · 9 There is a growing trend to mark capacitors very clearly in nanofarads. Be sure not to confuse 10nf or 100nf with 10 or 100 picofarads! There's more! Some manufacturers don't care about codes and print the value and tolerance VERY plainly. E.g.,. "820+20%" means 820 pf. at 20% tolerance. Yet another style of capacitor for values such as .1 uf is manufactured as a neat, rectangular block, with the value and other identifying data stamped on the top. For example, the information of interest to you in the marking ".1J63" on such a capacitor is the ".1" for .1 uf. RESISTORS The universal color coding of resistors does not change, fortunately, but resistor body colors and the style of wire leads can vary. Also, resistors may be packed loose or supplied on tape strips. Install any resistor as shown on the PC board parts layout diagram. Keep all leads as short as possible. 4 Band Code COLOR Black Brown Red Orange Yellow Green Blue Violet Gray White Gold Silver 1st BAND 0 1 2 3 4 5 6 7 8 9 2nd BAND 0 1 2 3 4 5 6 7 8 9 3rd BAND 0 1 2 3 4 5 6 7 8 9 MULTIPLIER 1 ohm 10 ohms 100 ohms 1K ohm 10K ohm 100K ohm 1M ohm TOLERANCE +/- 1% (F) +/-2% (G) +/-0.5% (D) +/-0.25% (C) +/-0.10% (B) +/-0.05% 0.1 0.01 +/- 5% (J) +/- 10% (K) 5 Band Code CPO3 · 10 BOARD SOLDERING Unprofessional soldering practices are the nightmare of ANY electronics manufacturer or service shop. GOOD soldering is essential to the performance of your project. A "cold" solder connection is caused by too little heat OR by heating only the component wire and not the wire and PC copper foil together. The tell-tale sign of too little heat is a dull, rough-looking connection. If you heat only the wire, the solder forms a cute ball around the wire, and rosin may completely insulate your ball from the copper. SOLDER BRIDGES You probably know that a solder bridge is a perfect and unintended connection of two PC board points that should NOT be connected. They happen most easily when soldering IC's and other devices with pins close together. The only technique for avoiding solder bridges is for you to be in complete control of the tip of your soldering pencil. The best single tools for avoiding bridges are a proper point on the soldering iron, bright light, perhaps with some magnification of your work, and thin diameter solder. Study your connection before you zap it with heat and solder. Choose the best "approach angle" for the iron's tip to heat the connection. Plan ahead to let your solder do what YOU want it to do, and you just won't make any solder bridges! TEN COMMANDMENTS OF GOOD PC-BOARD SOLDERING 1. If the soldering iron tip is covered with burned rosin, it cannot heat your connection very well. 2. If you heat only the wire and not the wire and PC trace together, a cold, bad connection is likely. 3. If your soldering tip is big enough to bridge two adjoining connections, it probably will! 4. Dirty, grubby solder will contribute to dirty, grubby connections. 5. Any use of acid core (plumbers!) solder in electronics work will destroy everything...DON'T USE IT! 6. A connection in a large area of PC-board copper requires more heat than one pin of an IC. 7. If your connection looks dull or brittle, it's no good. 8. If your connection looks like a ball instead of a shiny cone, it's no good. 9. Thin diameters of shiny, fresh rosin core solder are easier to use for KIT PC board work than thicker "hardware store" solder. 10. Pre-tin any stranded hookup wires leading in and out of your PC board kit project. It will prevent problems later! CPO3 · 11 ASSEMBLY INSTRUCTIONS In ALL PC board assembly steps, our word "INSTALL" means to do this: · · Insert the part, oriented or "pointed" correctly, into its holes in the PC board. If helpful, gently BEND the part's wire leads or tabs to hold it in place, with the body of the part snugly against the top side ("component side") of the circuit board. The "component side" is silkscreened with the part numbers for easy parts location identification. Solder ALL wires or pins of the part. Trim or "nip" all excess wire lengths extending beyond each solder connection, taking care that wire trimmings do not become lodged in solder connections. Follow the assembly instructions IN SEQUENCE and check off each step as understood and completed. Examine the schematic circuit diagram and PC Board parts layout diagram as you proceed. · · · · Use good soldering techniques! Let your soldering iron tip heat both the component lead wire and PC board trace enough so that the wire itself AND the foil trace BOTH become hot enough TOGETHER to melt a bit of solder so that it flows smoothly from the pin to the PC board trace. Enough said... Let's get building! As you build your code practice oscillator kit, save a couple of clipped off leads from capacitors and resistors. These will be needed later. If you throw out your lead scraps you'll have to find buss wire to make these important connections. 1. Install U1, the NE555 timer/oscillator IC. To ensure that the part is seated flat on the PC board, mount the part and place the circuit board component side down on the table top before soldering the leads. This will keep the IC from moving while you solder it. Solder all 8 pins. 2. Install C2, .01 µF ceramic disc capacitor (marked .01, 103, or 10nF). 3. Install C1, .1 µF ceramic disc capacitor (marked .1 or 104 or 100nF). 4. Install R3, 10K ohm (brown-black-orange). 5. Install R1, 1K ohm (brown-black-red). 6. Install R2, 270 ohm (red-violet-brown). 7. You will now need to install a jumper wire, JMP 1. Take one of your saved leads and form it into what looks like a staple whos ...