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Technician License Course Chapter 5 Operating Station Equipment Lesson Plan Module 11: Transmitters, Receivers and Transceivers Generalized Transceiver Categories • • • • • Single Band Dual Band Multimode Multiband Handheld (HT) VHF or UHF FM VHF/UHF FM VHF/UHF CW, SSB, FM HF and VHF/UHF Single Band Transceiver • Probably the most common starter rig. • Operates from 12 volts dc, requires external power supply. • Requires an external antenna. • Can be operated mobile or as a base station. • Limited to frequency modulation (FM) and usually either 2 meters or 70 cm bands. • Up to approximately 50 watts output. Dual Band Transceiver • Same as the single band transceiver but includes additional band(s). • Most common are 2 meter and 70 cm bands. • Could add 6 meters, 222 MHz or 1.2 GHz. • Depending on antenna connectors, might require separate coax for each band or a duplexer for single coax. Multimode Transceiver • Can be single or multiband. • Main difference is that these rigs can operate on all major modes SSB/AM/FM, CW, Data, RTTY etc. • More features add complexity and cost. • Most flexible of the rigs that will allow you to explore new modes as you gain experience. Multiband Transceiver • Covers many bands – can be limited to HF or can be HF/VHF/UHF. • Also covers all modes. • Frequently 100 watts on HF, some power limitations on high bands (50 watts). • Larger units have internal power supplies, smaller units need external power (13.8 V). Handheld (HT) Transceiver • • • • Small handheld FM units. Can be single band or dual band. Limited power (usually 5 watts or less). Includes power (battery) and antenna in one package. • An attractive first starter rig – but make sure it is what you want. Side-by-Side Single Band Dual Band Multimode Multiband Handheld Freq Agility Limited Medium Medium Full Limited Functionality Limited Limited Full Full Limited Ease of Use Easy Medium Medium Difficult Easy Programming Easy Easy Medium Challenging Easy/Medium Power Low Low Medium High Low Cost Low Modest High High Low Rig Vocabulary • We will now go through some jargon and vocabulary specific to the functions and controls of a transmitter and receiver. – This is a way to discuss how to operate a transceiver. • These controls, though separate, are combined in a transceiver. Transmitter Controls and Functions • Main tuning dial (both TX and RX): – Controls the frequency selection via the variable frequency oscillator (VFO). – Could be an actual dial or key pad or programmed channels. – Variable frequency step size (tuning rate, resolution). – Could have more than one VFO (control more that one frequency at a time). Transmitter Controls and Functions • Mode selector (both TX and RX for multimode rigs). – AM/FM/SSB (LSB or USB) – CW – Data (RTTY) • Could be automatic based on recognized band plan. Transmitter Controls and Functions • Microphone controls – Gain • How loudly you need to talk to be heard. – Speech Compressor or Speech Processor • Compacting your speech into a narrow frequency range to enhance “punch.” – Too much gain or compression can cause problems. • Splatter (Signal too wide) • Over-deviation (FM) • Over-modulation (AM, SSB) Transmitter Controls and Functions • Automatic Level Control (ALC). – Automatically limits transmitter drive (output level) to prevent problems associated with too much gain or compression. • Also can control external power amplifier operation. Transmitter Controls and Functions • Transmitter on/off – Push-to-Talk (PTT) – Voice-Operated Transmission (VOX) • VOX Gain • VOX Delay • Anti-VOX – Key jack Transmitter Controls and Functions • Microphones (Mic) – Hand mics – Desk mics • Preamplified desk mikes – Speaker-mics – Headsets or boom-sets – Internal mikes • Speak across the mic, not into the mic. Transmitter Controls and Functions • Microphones (Mic) • Almost every manufacturer has a different wiring arrangement for their mic connections. • There will be connections for PTT and usually control voltages. Transmitter Controls and Functions • Morse Keys – – – – Straight key Electronic keyer and paddle Semi-automatic (Bug) A computer keyboard and software can also be used. Transceiver Special Features • Memories – Many transceivers have memory banks that allow the storage of frequency, offset / shift, CTCSS tone, power, and other settings; for easy recall. • Function Key – Many radios have so many features, that to access them from the available buttons on the radio, a “function” or “F” key is used to switch between menu options. Receiver Controls and Functions • AF Gain or Volume – Controls the audio level to the speaker or headphones. • RF Gain – Controls the strength of radio signal entering the receiver. – Used to limit (attenuate) very strong local signals. – Usually operated in the full-open position. Receiver Controls and Functions • Automatic Gain Control (AGC) – Automatically limits the incoming signals during signal (voice) peaks. • Prevents peaks from capturing the receiver and limiting reception of lower level portions of the incoming signal. – Fast setting for CW. – Slow settings for SSB and AM. – Not used in FM because of the type of signal used in FM. Receiver Controls and Functions • Squelch (Carrier Squelch) – Turns off audio to speaker when signal is not present. • Used in FM primarily – Open – allows very weak signals to pass through (along with noise). – Tight – allows only the strongest signals to pass through. • Advance the squelch control until the noise just disappears. Receiver Controls and Functions • Filters – Bandwidth filter • Used to narrow the width of the audio signal that is passed. • Can attenuate adjacent interference. • 2400 Hz for SSB • 500 Hz or 300 Hz for CW Receiver Controls and Functions • Filters – Notch filter • Very narrow filter that can be moved over an interfering signal to attenuate it. – Noise blanker or limiter • Limits signal spikes that are frequently associated with random naturally generated noise. Receiver Controls and Functions • Reception and Transmission Meter. – In transmit, indicates output power or ALC or other functions as selected by switch setting. • In receive - indicates signal strength. – In “S” units S1 through S9 – S9 is strongest. – Also have dB over S9 to cover very strong signals. Receiver Controls and Functions • Receivers can be limited to ham bands or can cover other parts of the spectrum. • General coverage receivers cover a wide area of the spectrum and can be used for shortwave listening (SWL). Receiver Controls and Functions • RIT – Receiver Incremental Tuning – Used to readjust the receive frequency without altering the transmit frequency ( HF – SSB) • “Shift” – Controls the offset between transmit and receive frequencies in VHF/UHF FM transceivers Handheld Transceivers • Single, dual and multiband versions (with increasing cost and complexity). – Some have expanded receiver coverage (wideband receive). • Very portable and self-contained. – Internal microphone and speaker. – Rubber duck antenna. – Battery powered. Nice to have handheld accessories • • • • • Extra battery packs. Drop-in, fast charger. Extended antenna. External microphone and speaker. Headset. Which of the following describes the muting of receiver audio controlled solely by the presence or absence of an RF signal? (T2B03) • • • • A. B. C. D. Tone squelch Carrier squelch CTCSS Modulated carrier Which of the following describes the muting of receiver audio controlled solely by the presence or absence of an RF signal? (T2B03) • • • • A. B. C. D. Tone squelch Carrier squelch CTCSS Modulated carrier Which of the following is true concerning the microphone connectors on amateur transceivers? (T4A01) • A. All transceivers use the same microphone connector type • B. Some connectors include push-to-talk and voltages for powering the microphone • C. All transceivers using the same connector type are wired identically • D. Un-keyed connectors allow any microphone to be connected Which of the following is true concerning the microphone connectors on amateur transceivers? (T4A01) • A. All transceivers use the same microphone connector type • B. Some connectors include push-to-talk and voltages for powering the microphone • C. All transceivers using the same connector type are wired identically • D. Un-keyed connectors allow any microphone to be connected What may happen if a transmitter is operated with the microphone gain set too high? (T4B01) • A. The output power might be too high • B. The output signal might become distorted • C. The frequency might vary • D. The SWR might increase What may happen if a transmitter is operated with the microphone gain set too high? (T4B01) • A. The output power might be too high • B. The output signal might become distorted • C. The frequency might vary • D. The SWR might increase Which of the following can be used to enter the operating frequency on a modern transceiver? (T4B02) • • • • A. B. C. D. The keypad or VFO knob The CTCSS or DTMF encoder The Automatic Frequency Control All of these choices are correct Which of the following can be used to enter the operating frequency on a modern transceiver? (T4B02) • • • • A. B. C. D. The keypad or VFO knob The CTCSS or DTMF encoder The Automatic Frequency Control All of these choices are correct What is the purpose of a squelch control on a transceiver? (T4B03) • A. To set the highest level of volume desired • B. To set the transmitter power level • C. To adjust the automatic gain control • D. To mute receiver output noise when no signal is being received What is the purpose of a squelch control on a transceiver? (T4B03) • A. To set the highest level of volume desired • B. To set the transmitter power level • C. To adjust the automatic gain control • D. To mute receiver output noise when no signal is being received What is a way to enable quick access to a favorite frequency on your transceiver? (T4B04) • A Enable the CTCSS tones • B. Store the frequency in a memory channel • C. Disable the CTCSS tones • D. Use the scan mode to select the desired frequency What is a way to enable quick access to a favorite frequency on your transceiver? (T4B04) • A Enable the CTCSS tones • B. Store the frequency in a memory channel • C. Disable the CTCSS tones • D. Use the scan mode to select the desired frequency Which of the following would reduce ignition interference to a receiver? (T4B05) • • • • A. B. C. D. Change frequency slightly Decrease the squelch setting Turn on the noise blanker Use the RIT control Which of the following would reduce ignition interference to a receiver? (T4B05) • • • • A. B. C. D. Change frequency slightly Decrease the squelch setting Turn on the noise blanker Use the RIT control Which of the following controls could be used if the voice pitch of a single-sideband signal seems too high or low? (T4B06) • • • • A. B. C. D. The AGC or limiter The bandwidth selection The tone squelch The receiver RIT or clarifier Which of the following controls could be used if the voice pitch of a single-sideband signal seems too high or low? (T4B06) • • • • A. B. C. D. The AGC or limiter The bandwidth selection The tone squelch The receiver RIT or clarifier What does the term “RIT” mean? (T4B07) • • • • A. B. C. D. Receiver Input Tone Receiver Incremental Tuning Receiver Inverter Test Remote Input Transmitter What does the term “RIT” mean? (T4B07) • • • • A. B. C. D. Receiver Input Tone Receiver Incremental Tuning Receiver Inverter Test Remote Input Transmitter What is the advantage of having multiple receive bandwidth choices on a multimode transceiver? (T4B08) • A. Permits monitoring several modes at once • B. Permits noise or interference reduction by selecting a bandwidth matching the mode • C. Increases the number of frequencies that can be stored in memory • D. Increases the amount of offset between receive and transmit frequencies What is the advantage of having multiple receive bandwidth choices on a multimode transceiver? (T4B08) • A. Permits monitoring several modes at once • B. Permits noise or interference reduction by selecting a bandwidth matching the mode • C. Increases the number of frequencies that can be stored in memory • D. Increases the amount of offset between receive and transmit frequencies Which of the following is an appropriate receive filter to select in order to minimize noise and interference for SSB reception? (T4B09) • • • • A. B. C. D. 500 Hz 1000 Hz 2400 Hz 5000 Hz Which of the following is an appropriate receive filter to select in order to minimize noise and interference for SSB reception? (T4B09) • • • • A. B. C. D. 500 Hz 1000 Hz 2400 Hz 5000 Hz Which of the following is an appropriate receive filter to select in order to minimize noise and interference for CW reception? (T4B10) • • • • A. B. C. D. 500 Hz 1000 Hz 2400 Hz 5000 Hz Which of the following is an appropriate receive filter to select in order to minimize noise and interference for CW reception? (T4B10) • • • • A. B. C. D. 500 Hz 1000 Hz 2400 Hz 5000 Hz What device increases the low-power output from a handheld transceiver? (T7A10) • • • • A. B. C. D. A voltage divider An RF power amplifier An impedance network A voltage regulator What device increases the low-power output from a handheld transceiver? (T7A10) • • • • A. B. C. D. A voltage divider An RF power amplifier An impedance network A voltage regulator What can you do if you are told your FM handheld or mobile transceiver is over deviating? (T7B01) • • • • A. B. C. D. Talk louder into the microphone Let the transceiver cool off Change to a higher power level Talk farther away from the microphone What can you do if you are told your FM handheld or mobile transceiver is over deviating? (T7B01) • • • • A. Talk louder into the microphone B. Let the transceiver cool off C. Change to a higher power level D. Talk farther away from the microphone What is the primary purpose of a dummy load? (T7C01) • A. To prevent the radiation of signals when making tests • B. To prevent over-modulation of your transmitter • C. To improve the radiation from your antenna • D. To improve the signal to noise ratio of your receiver What is the primary purpose of a dummy load? (T7C01) • A. To prevent the radiation of signals when making tests • B. To prevent over-modulation of your transmitter • C. To improve the radiation from your antenna • D. To improve the signal to noise ratio of your receiver Which of the following can be used to transmit CW in the amateur bands? (T8D10) • • • • A. B. C. D. Straight Key Electronic Keyer Computer Keyboard All of these choices are correct Which of the following can be used to transmit CW in the amateur bands? (T8D10) • • • • A. B. C. D. Straight Key Electronic Keyer Computer Keyboard All of these choices are correct Data Modes • Connecting computers via ham radio. – Some systems use radio to connect to Internet gateways. • The bulk of the work is done by specialized modems or computer software/sound card. – Terminal Node Controller (TNC). – Multiple Protocol Controller (MPC). Popular Digital Modes • Radioteletype (RTTY) (Baudot Code) • PSK31 (Phase Shift Keying) Low data rate. • Packet Radio • Automatic Packet Reporting System (APRS) • Winlink (e-mail via radio) Digital Modes • CW is the oldest digital mode. – Uses International Morse Code • Data sent over radio is subject to disruption due to noise, fading, etc. The rate that the signal has errors is known as the Bit Error Rate (BER). • Many digital modes have some error correction method built in, such as sending a parity bit. Automatic Position Reporting System (APRS) Data Station Setup Internet Gateway Which of the following would be connected between a transceiver and computer in a packet radio station? (T4A06) • • • • A. B. C. D. Transmatch Mixer Terminal node controller Antenna Which of the following would be connected between a transceiver and computer in a packet radio station? (T4A06) • • • • A. B. C. D. Transmatch Mixer Terminal node controller Antenna • • • • How is the computer’s sound card used when conducting digital communications using a computer? (T4A07) A. The sound card communicates between the computer CPU and the video display B. The sound card records the audio frequency for video display C. The sound card provides audio to the microphone input and converts received audio to digital form D. All of these choices are correct • • • • How is the computer’s sound card used when conducting digital communications using a computer? (T4A07) A. The sound card communicates between the computer CPU and the video display B. The sound card records the audio frequency for video display C. The sound card provides audio to the microphone input and converts received audio to digital form D. All of these choices are correct What does the acronym “BER” mean when applied to digital communications systems? (T7B12) • • • • A. B. C. D. Baud Enhancement Recovery Baud Error Removal Bit Error Rate Bit Exponent Resource What does the acronym “BER” mean when applied to digital communications systems? (T7B12) • • • • A. B. C. D. Baud Enhancement Recovery Baud Error Removal Bit Error Rate Bit Exponent Resource What name is given to an amateur radio station that is used to connect other amateur stations to the Internet? (T8C11) • • • • A. B. C. D. A gateway A repeater A digipeater A beacon What name is given to an amateur radio station that is used to connect other amateur stations to the Internet? (T8C11) • • • • A. B. C. D. A gateway A repeater A digipeater A beacon Which of the following is an example of a digital communications method? (T8D01) • • • • A. B. C. D. Packet PSK31 MFSK All of these choices are correct Which of the following is an example of a digital communications method? (T8D01) • • • • A. B. C. D. Packet PSK31 MFSK All of these choices are correct What does the term APRS mean? (T8D02) • • • • A. B. C. D. Automatic Position Reporting System Associated Public Radio System Auto Planning Radio Set-up Advanced Polar Radio System What does the term APRS mean? (T8D02) • A. Automatic Position Reporting System • B. Associated Public Radio System • C. Auto Planning Radio Set-up • D. Advanced Polar Radio System Which of the following is normally used when sending automatic location reports via amateur radio? (T8D03) • A. A connection to the vehicle speedometer • B. A WWV receiver • C. A connection to a broadcast FM sub-carrier receiver • D. A Global Positioning System receiver Which of the following is normally used when sending automatic location reports via amateur radio? (T8D03) • A. A connection to the vehicle speedometer • B. A WWV receiver • C. A connection to a broadcast FM sub-carrier receiver • D. A Global Positioning System receiver What does the abbreviation PSK mean? (T8D06) • • • • A. B. C. D. Pulse Shift Keying Phase Shift Keying Packet Short Keying Phased Slide Keying What does the abbreviation PSK mean? (T8D06) • • • • A. B. C. D. Pulse Shift Keying Phase Shift Keying Packet Short Keying Phased Slide Keying What is PSK31? (T8D07) • A. A high-rate data transmission mode • B. A method of reducing noise interference to FM signals • C. A method of compressing digital television signal • D. A low-rate data transmission mode What is PSK31? (T8D07) • A. A high-rate data transmission mode • B. A method of reducing noise interference to FM signals • C. A method of compressing digital television signal • D. A low-rate data transmission mode Which of the following may be included in packet transmissions? (T8D08) • A. A check sum which permits error corrections • B. A header which contains the call sign of the station to which the information is being sent • C. Automatic repeat request in case of error • D. All of these choices are correct Which of the following may be included in packet transmissions? (T8D08) • A. A check sum which permits error corrections • B. A header which contains the call sign of the station to which the information is being sent • C. Automatic repeat request in case of error • D. All of these choices are correct What code is used when sending CW in the amateur bands? (T8D09) • • • • A. B. C. D. Baudot Hamming International Morse Gray What code is used when sending CW in the amateur bands? (T8D09) • • • • A. B. C. D. Baudot Hamming International Morse Gray What is a “parity” bit? (T8D11) • A. A control code required for automatic position reporting • B. A timing bit used to ensure equal sharing of a frequency • C. An extra code element used to detect errors in received data • D. A “triple width” bit used to signal the end of a character What is a “parity” bit? (T8D11) • A. A control code required for automatic position reporting • B. A timing bit used to ensure equal sharing of a frequency • C. An extra code element used to detect errors in received data • D. A “triple width” bit used to signal the end of a character