Koker serves to regulate or determine the frequency of the radio transmitter. In koker also Ferrite that serves as a core inductor in addition there is an inductance coil comprising primary and secondary winding. Way of working is to facilitate search koker empty wave. When filling koker in turn to the right to a maximum frequency of the oscillator produce more low. If the FM transmitter lights, turn left up the core koker to hissing on the FM radio signal is lost it will be found a strong and stable.
Transistors have two connections, one of which is the emitter and the other base and collector. Because this is a transistor as two diodes. ransistor C1970 type normally used to raise the voltage 0.8 to 1 watt, I think it was in the C1970 study could increase about 8 times. On the C1971 transistor can be coupled directly from the exciter circuit and the voltage of 6.5 to 7 watts or bias raised about 10 times. If the C1970 to C1971 join the output power of about 12 watts or more. (All will be explained in Chapter III)
• For a state that is not worth going to get SWR> 1.
• For the worst circumstances in which all power is reflected back dating (Pf = Pr) will get the SWR = infinity.
CHAPTER III PLANNING AND DEVELOPMENT TOOLS
4.2 Testing exciter circuit
• The purpose To find out if the oscillator can work well and achieve the desired frequency. And also to determine whether the buffer is running properly.
• The equipment used A. Koker 2. Inductor 3. Transistor 4. Resistor 5. Trimer 6. Dummy Load 7. 5 volt power supply 8. Multimeter 9. Frequency Counter 10. PCB
• The test procedure Test Block Diagram A. Assemble the equipment used in accordance Picture 2. Provide 12 volt power supply to the exciter circuit 3. Switch the exciter circuit to get the most power in large 4. Calculate the voltage at TP 1, TP 2 and, TP 3 5. Observe the output (at V output)
• The test results The test results are shown in Table. the following: Exciter circuit Testing Results Test Results Point A 0.6V 2 0.6V 3 11.75 V
4.3 Testing a series of booster
• The purpose To gain greater power and also increase the distance range of further emission up to 7-fold.
• The equipment used A. Inductor 2. Transistor 3. Trimer 4. Dummy Load 5. 12 Volt Power Supply
• The test procedure Testing Block Diagram Picture Booster: A. Assemble the equipment used in accordance Picture 2. Large test circuit voltage that can be accepted 3. Observing the output
• The test results The test results are shown in Table. the following: Booster circuit Testing Results Test Results Point 4 11,75 5 11,75
CHAPTER V CLOSING
5.1. Conclusion Based on the test results it can be concluded:
• In a series of FM transmitters we've made, the power output is only 2 Watt for C1970 transistor used is that only 1 Watt power up
• FM transmitter that can be made only reach 93 MHz frequency
• The distance achieved depends on the power emitted by the FM transmitter
• If you want to make the transmitter starts with a good oscillator.
• If you want to make a series of FM with a power greater then use the transistor C1971, C1946. the power generated about 25 watts.
• To balance the output of the FM transmitter mounted circuit PLL (Phase Local Loop).