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Amateur Extra Licensing Class

Amateur Extra Licensing Class. Presented by W5YI Arlington, Texas. Modulate Your Transmitters. Amateur Radio Extra Class Element 4 Course Presentation. ELEMENT 4 Groupings Rules & Regs Skywaves & Contesting Outer Space Comms Visuals & Video Modes

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Amateur Extra Licensing Class

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  1. Amateur Extra Licensing Class Presented by W5YI Arlington, Texas Modulate Your Transmitters

  2. Amateur Radio Extra ClassElement 4 Course Presentation • ELEMENT 4 Groupings • Rules & Regs • Skywaves & Contesting • Outer Space Comms • Visuals & Video Modes • Digital Excitement with Computers & Radios • Modulate Your Transmitters • Amps & Power Supplies • Receivers with Great Filters

  3. Amateur Radio Extra ClassElement 4 Course Presentation ELEMENT 4 Groupings Oscillate & Synthesize This! Circuits & Resonance for All! Components in Your New Rig Logically Speaking of Counters Optos & OpAmps Plus Solar Test Gear, Testing, Testing 1,2,3 Antennas Feedlines & Safety

  4. Amateur Radio Extra ClassModulate Your Transmitters E8B01… Modulation index is the term for the ratio between the frequency deviation of an RF carrier wave, and the modulating frequency of its corresponding FM-phone signal. E8B02 The modulation index of a phase-modulated emission does not depend on the RF carrier frequency. Modulation index (x) = Peak Deviation (D) / Modulation frequency (m) E8B03… The modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency, when the modulating frequency is 1000 Hz is 3.0. E8B04… The modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2-kHz modulating frequency is 3.0. 3.0 Modulation index = Deviation / Modulation frequency 3000/1000 3.0 Modulation index = Deviation / Modulation frequency 6000/2000

  5. Amateur Radio Extra ClassModulate Your Transmitters General Spectrum Deviation Ratio of 3 Frequency spectrum of FM signals.

  6. Amateur Radio Extra ClassModulate Your Transmitters Deviation Radio of 1.67 Deviation Ration of 5 Frequency spectrum of FM signals.

  7. Amateur Radio Extra ClassModulate Your Transmitters E8B10…Deviation ratio is the ratio of the maximum carrier frequency deviation to the highest audio modulating frequency. Deviation Ratio = maximum carrier deviation/highest modulating frequency E8B05… The deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz and accepting a maximum modulation rate of 3 kHz is 1.66. E8B06… The deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz and accepting a maximum modulation frequency of 3.5 kHz is 2.14. E8B08… The modulating signal in a pulse-position modulation system will vary the time at which each pulse occurs. Deviation Ratio = Max Deviation / Max Modulation frequency 5000/3000 1.666 Deviation Ratio = Max Deviation / Max Modulation frequency 2.142 7500/3500

  8. Amateur Radio Extra ClassModulate Your Transmitters E8B09… The pulses of a pulse-modulated signal are usually transmitted as a pulse of relatively short duration and sent with a relatively long period of time separating each pulse. This keeps the average power much lower than the peak power. E8B07… When using a pulse-width modulation system, the transmitter's peak power is greater than its average power because the signal duty cycle is less than 100%. E8B11… Frequency division multiplexing can be used to combine several separate analog information streams into a single analog radio frequency signal.

  9. Amateur Radio Extra ClassModulate Your Transmitters E8B12… In frequency division multiplexing, two or more information streams are merged into a "baseband", which then modulates the transmitter. E8B13…In time division multiplexing two or more signals are arranged to share discrete time slots of a digital data transmission.

  10. Amateur Radio Extra ClassModulate Your Transmitters E8D01…Peak-to-peak voltage is the easiest voltage amplitude parameter to measure when viewing a pure sine wave signal on an oscilloscope

  11. Amateur Radio Extra ClassModulate Your Transmitters E1XXX… E1XXX… E1XXX… E1XXX…

  12. Amateur Radio Extra ClassModulate Your Transmitters E8D02… The relationship between the peak-to-peak voltage and the peak voltage amplitude of a symmetrical waveform is 2:1. The peak to peak includes both the positive and negative excursions of the sine wave, therefore it is twice the value of only the peak voltage. E8A01… A square wave is made up of a sine wave plus all of its odd harmonics. Sawtooth Sine Wave Square Wave Sine wave plus odd harmonics

  13. Amateur Radio Extra ClassModulate Your Transmitters E8A02…A sawtooth wave has a rise time significantly faster than its fall time (or vice versa). E8A03… A sawtooth wave is made up of sine waves of a given fundamental frequency plus all of its harmonics. or

  14. Amateur Radio Extra ClassModulate Your Transmitters E8A04… The equivalent to the root-mean-square value of an AC voltage is the equivalent DC voltage that causes the same amount of heating in a resistor.

  15. Amateur Radio Extra ClassModulate Your Transmitters E8A05… The most accurate way of measuring the RMS voltage of a complex waveform is by measuring the heating effect in a known resistor. E8A07… The characteristics of a modulating signal determine the PEP-to-average power ratio of a single-sideband phone signal. In precision measuring instruments a filament is heated with a current from an AC circuit and its temperature is measured by the voltage generated in a thermocouple attached to it. Then a DC current is applied to generate the same thermocouple voltage output. This DC current is then equal to the AC RMS current. On SSB transmit, peak envelope power (PEP) is determined by your speech characteristics.

  16. Amateur Radio Extra ClassModulate Your Transmitters E8A06… The approximate ratio of PEP-to-average power for a typical voice-modulated single-sideband phone signal is 2.5 to 1. Spectral plot of a SSB signal.

  17. Amateur Radio Extra ClassModulate Your Transmitters E8D13…A peak-reading wattmeter should be used to monitor the output signal of a voice-modulated single-sideband transmitter to ensure you do not exceed the maximum allowable power. E8D06… The advantage of using a peak-reading wattmeter to monitor the output of a SSB phone transmitter is that it gives a more accurate display of the PEP output when modulation is present. E8D04… The PEP output of a transmitter that has a maximum peak of 30 volts to a 50-ohm load as observed on an oscilloscope is 9 watts. RMS = .707 x Peak RMS = .707 x 30 RMS=21.21 Volts Power = (RMS)2 / Resistance P = (21.21)2 / 50 P = 449.86 / 50 P = 8.997 Watts

  18. Amateur Radio Extra ClassModulate Your Transmitters E8D14…The average power dissipated by a 50-ohm resistive load during one complete RF cycle having a peak voltage of 35 volts is 12.2 watts. E8D15… If an RMS reading voltmeter reads 34 volts on a sinusoidal waveform, it’s peak voltage would be 48 volts. E8D16… 170 volts is a typical value for the peak voltage at a common household electrical outlet. RMS= .707 x Peak RMS = .707 x 35 RMS = 24.74 Volts Power = (RMS)2 / Resistance P = (24.74)2 / 50 P = 612.31 / 50 P = 12.24 Watts Peak = 1.414 x RMS Peak = 1.414 x 34 Peak = 48.07 volts Peak = 1.414 x RMS Peak = 1.414 x 120 Peak = 169.68 volts

  19. Amateur Radio Extra ClassModulate Your Transmitters E8D17… 340 volts is a typical value for the peak-to-peak voltage at a common household electrical outlet. E8D18… A typical value for the RMS voltage at a common household electrical power outlet is 120-V AC. E8D19… The RMS value of a 340-volt peak-to-peak pure sine wave is 120-V AC. Peak to Peak = 2(1.414 x RMS) PP = 2 (1.414 x 120) PP = 2 x 169.68 Peak to Peak = 339.36 volts RMS= (peak to Peak/2) / 1.414 RMS= (340/2) / 1.414 RMS= 170 / 1.414 RMS = 120.22 volts

  20. Amateur Radio Extra ClassModulate Your Transmitters E8D05… If an RMS-reading AC voltmeter reads 65 volts on a sinusoidal waveform, the peak-to-peak voltage would be 184 volts. E8A08… The period of a wave is the time required for it to complete one full cycle. Peak to Peak = 2(RMS x 1.414) PP = 2 (65 x 1.414) PP = 2 x 91.91 Peak Peak = 183.82 volts Pure sine wave.

  21. Amateur Radio Extra ClassModulate Your Transmitters E8A09… An irregular waveform is produced by human speech. E8A13… One advantage of using digital signals instead of analog signals to convey the same information is that digital signals can be regenerated multiple times without error. E8A12… Human speech, Video signals and Data information can all be conveyed using digital waveforms. This is because human speech is complex and contains many frequencies.

  22. Amateur Radio Extra ClassModulate Your Transmitters E8A14… Sequential sampling is commonly used to convert analog signals to digital signals. E8A15… The waveform of a digital data stream signal would look like a series of pulses with varying patterns on a conventional oscilloscope. E8A10… The distinguishing characteristic of a pulse waveform is narrow bursts of energy separated by periods of no signal.

  23. Amateur Radio Extra ClassModulate Your Transmitters E8A11…Digital data transmission is one use for a pulse modulated signal. E7E01… A reactance modulator on the oscillator can be used to generate FM-phone emissions. E7E02… The function of a reactance modulator is to produce PM (Phase Modulated) signals by using an electrically variable inductance or capacitance.

  24. Amateur Radio Extra ClassModulate Your Transmitters E7E03…The fundamental principle of a phase modulator is it varies the tuning of an amplifier tank circuit to produce PM (phase Modulated) signals. E7E05… A pre-emphasis network is added to an FM transmitter to proportionally attenuate the lower audio frequencies.

  25. Amateur Radio Extra ClassModulate Your Transmitters E7E04… One way a single-sideband phone signal can be generated is by using a balanced modulator followed by a filter. A balanced mixer will output the sum and difference of the two signals applied (Carrier and SSB audio) and the carrier, suppressed by passing the modulator output through a filter so that the upper or lower sideband can be filtered leaving only one of the sideband signals.

  26. Amateur Radio Extra ClassModulate Your Transmitters E7E14…The phasing or quadrature method describes a common means of generating a SSB signal when using digital signal processing. E7C09… A Hilbert-transform filter type of digital signal processing filter might be used in generating an SSB signal. E6E01… A filter bandwidth of 2.4 kHz at -6 dB would be a good choice for use in a SSB radiotelephone transmitter. Block diagram of a basic digital signal processing (DSP) system

  27. Amateur Radio Extra ClassModulate Your Transmitters E1B01… A spurious emission is an emission outside the necessary bandwidth that can be reduced or eliminated without affecting the information transmitted. E1B08… An amateur station operation is restricted, if its emissions cause interference to the reception of a domestic broadcast station on a receiver of good engineering design, on those amateur service frequencies that cause interference to the broadcast receiver. E7B11… The type of circuit shown is a common emitter amplifier. Emitter is at AC ground because of C3.

  28. Amateur Radio Extra ClassModulate Your Transmitters E7B09…In Figure E7-1, the purpose of R1 and R2 are to set a fixed bias level. E7B10… In Figure E7-1, the purpose of R1 and R2 are to set a fixed bias level. E7B12… In Figure E7-2, the purpose of R is to serves as an Emitter load. E7B13… In Figure E7-2, the purpose of C2 is Output coupling. Figure E7-1 Figure E7-2

  29. Amateur Radio Extra ClassModulate Your Transmitters E7C01…In a low-pass filter Pi-network the circuit consists of a capacitor in parallel with the input, another capacitor in parallel with the output, and an inductor in series between the two and between the network's input and output. E7C02… A T-network with series capacitors and a parallel (shunt) inductor transforms impedance and is a high-pass filter. Pi Low pass filter T-Network High pass T-Network Low pass

  30. Amateur Radio Extra ClassModulate Your Transmitters E7C03… The advantage of a Pi-L-network over a Pi-network for impedance matching between the final amplifier of a vacuum-tube type transmitter and an antenna is greater harmonic suppression. E7C11… Pi Filter is the common name for a filter network which is equivalent to two L networks back-to-back. Pi-L network Pi Low pass (single inductor)

  31. Amateur Radio Extra ClassModulate Your Transmitters E7C12… A Pi-L network, which is a network consisting of two series inductors and two shunt capacitors, is used when matching a vacuum-tube final amplifier to a 50-ohm unbalanced output. E7C13… One advantage of a Pi matching network over an L matching network is that the Q of Pi networks can be varied depending on the component values chosen. E7B08… When tuning a vacuum tube RF power amplifier that employs a pi-network output circuit transmitter output stage, the tuning capacitor should adjusted for minimum plate current, while the loading capacitor is adjusted for maximum permissible plate current.

  32. Amateur Radio Extra ClassModulate Your Transmitters E7C04… A network can transform complex impedance to resistive impedance by canceling the reactive part of an impedance and transforming the resistive part to the desired value. E4D03… Intermodulation interference between two repeaters can occur when the repeaters are in close proximity and the signals mix in one or both transmitter final amplifiers. E4D08… Nonlinear circuits or devices cause intermodulation in an electronic circuit. E4D06… If the signals of two transmitters mix together in one or both of their final amplifiers and unwanted signals at the sum and difference frequencies of the original signals are generated, the signals are called intermodulation interference.

  33. Amateur Radio Extra ClassModulate Your Transmitters E4D06…If the signals of two transmitters mix together in one or both of their final amplifiers and unwanted signals at the sum and difference frequencies of the original signals are generated, the signals are called intermodulation interference. E7C10… A cavity filter would be the best choice for use in a 2-meter repeater duplexer.

  34. Amateur Radio Extra ClassModulate Your Transmitters E4D04…An effective way to reduce or eliminate intermodulation interference between two repeater transmitters operating in close proximity to one another is to install a properly terminated circulator at the output of the transmitter. E4D08… Nonlinear circuits or devices cause intermodulation in an electronic circuit. E7B18… A klystron is a VHF, UHF, or microwave vacuum tube that uses velocity modulation.

  35. Element 4 Extra Class Question Pool Modulate Your Transmitters Valid July 1, 2008 Through June 30, 2012

  36. E8B01What is the term for the ratio between the frequency deviation of an RF carrier wave, and the modulating frequency of its corresponding FM-phone signal? FM compressibility Quieting index Percentage of modulation Modulation index

  37. E8B02How does the modulation index of a phase-modulated emission vary with RF carrier frequency (the modulated frequency)? It increases as the RF carrier frequency increases It decreases as the RF carrier frequency increases It varies with the square root of the RF carrier frequency It does not depend on the RF carrier frequency

  38. E8B03What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency, when the modulating frequency is 1000 Hz? 3 0.3 3000 1000

  39. E8B04What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2-kHz modulating frequency? 6000 3 2000 1/3

  40. E8B10 What is meant by deviation ratio? The ratio of the audio modulating frequency to the center carrier frequency The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency The ratio of the carrier center frequency to the audio modulating frequency The ratio of the highest audio modulating frequency to the average audio modulating frequency

  41. E8B05What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz and accepting a maximum modulation rate of 3 kHz? 60 0.167 0.6 1.67

  42. E8B06What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz and accepting a maximum modulation frequency of 3.5 kHz? 2.14 0.214 0.47 47

  43. E8B08What parameter does the modulating signal vary in a pulse-position modulation system? The number of pulses per second The amplitude of the pulses The duration of the pulses The time at which each pulse occurs

  44. E8B09How are the pulses of a pulse-modulated signal usually transmitted? A pulse of relatively short duration is sent; a relatively long period of time separates each pulse A pulse of relatively long duration is sent; a relatively short period of time separates each pulse A group of short pulses are sent in a relatively short period of time; a relatively long period of time separates each group A group of short pulses are sent in a relatively long period of time; a relatively short period of time separates each group

  45. E8B07When using a pulse-width modulation system, why is the transmitter's peak power greater than its average power? The signal duty cycle is less than 100% The signal reaches peak amplitude only when voice modulated The signal reaches peak amplitude only when voltage spikes are generated within the modulator The signal reaches peak amplitude only when the pulses are also amplitude modulated

  46. E8B11Which of these methods can be used to combine several separate analog information streams into a single analog radio frequency signal? Frequency shift keying A diversity combiner Frequency division multiplexing Pulse compression

  47. E8B12Which of the following describes frequency division multiplexing? The transmitted signal jumps from band to band at a predetermined rate Two or more information streams are merged into a "baseband", which then modulates the transmitter The transmitted signal is divided into packets of information Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter

  48. E8B13What is time division multiplexing? Two or more data streams are assigned to discrete sub-carriers on an FM transmitter Two or more signals are arranged to share discrete time slots of a digital data transmission Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier Two or more signals are quadrature modulated to increase bandwidth efficiency

  49. E8D01What is the easiest voltage amplitude parameter to measure when viewing a pure sine wave signal on an oscilloscope? Peak-to-peak voltage RMS voltage Average voltage DC voltage

  50. E8D02What is the relationship between the peak-to-peak voltage and the peak voltage amplitude of a symmetrical waveform? 0.707:1 2:1 1.414:1 4:1

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