[Information] : Where a question shows [Information]. All the information given below that question is OK
Frequency Spectrum [Information]
ELF Extremly Low Frequency (3 KHz to 30 KHz) LF Low Frequency (30 KHz to 300 KHz) MF Medium Frequency (300 KHz to 3 MHz) HF High Frequency (3 MHz to 30 MHz)
VHF Very High Frequency (30 MHz to 300 MHz) UHF Ultra High Frequency (300 MHz to 3 GHz) SHF Super High Frequency (3 GHz to 30 GHz) EHF Extremely High Frequency (30 GHz to 300 GHz)
Carrier [Information]
A carrier wave is a radio-frequency wave that carries information. The information is attached to the carrier wave by means of a modulation process that involves the variation of one of the carrier-frequency characteristics, such as its amplitude, its frequency, or its duration.
Amplitude Modulation (AM) :: The frequency of the carrier is kept constant.
Frequency Modulation (FM) :The amplitude of the carrier wave is kept constant.
Phase Modulation (PM) : Modulation of the phase of a radio carrier wave by voice or other signal
Undesired oscillations developed in RF amplifier circuit at some frequency higher than normal operating frequency
parasitic
harmonic
frequent
supressed
Frequency Modulation (FM) : [Information]
FM : Is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave.
Frequency modulation, FM is widely used for a variety of radio communications applications. FM broadcasts on the VHF bands still provide exceptionally high quality audio, and FM is also used for a variety of forms of two way radio communications, and it is especially useful for mobile radio communications.
Frequency deviation is used in FM radio to describe the maximum difference between an FM modulated frequency and the nominal carrier frequency...... When the audio signal is modulated onto the radio frequency carrier, the new radio frequency signal moves up and down in frequency....The amount by which the signal moves up and down is important. It is known as the deviation and is normally quoted as the number of kilohertz deviation.
The typical amateur radio FM signal bandwidth varies from about 10 kHz to 15 kHz.
Peak-to-peak : [Information]
Peak-to-peak amplitude is the change between peak (highest amplitude value) and trough (lowest amplitude value, which can be negative).
Peak to peak value is the vertical distance between the top and bottom of the wave..... It will be measured in volts on a voltage waveform
Oscilloscopes are usually used to measure the peak to peak waveform.
In a SSB transmission, the carrier is:
inserted at the transmitter
transmitted with one sideband
of no use at the receiver
reinserted at the receiver
The actual length of the radiating element in a Marconi antenna is ____
one-quarter
one-half
one-three quarter
one-full
A device used for producing FM in transmitter :
balance modulator
frequency modulator
reactance modulator
amplitude modulator
Frequency bands used mostly for groundwave propagation such as AM broadcast stations
300-3000 Khz
3-30 Mhz
30-300 Mhz
30-300 GHz
Any unwanted form of energy tending to interfere with the proper and easy reception and reproduction of wanted signals
noise
static
karaoke
electrical
The use of ionosphere in wave propagation utilizes mostly this kind of radio wave :
ground waves
medium waves
sky waves
ultra waves
A disadvantage is that microwaves are limited to ________
mobile operation
voice communications
line of sight propagation
skywave propagation
Harmonics: [Information]
Q : What is meant by harmonic radiation? A : Unwanted signals at frequencies which are multiples of the fundamental (chosen) frequency
Q : Why is harmonic radiation from an amateur station not wanted? A : It may cause interference to other stations and may result in out-of-band signals
In a transmitter, excessive harmonics are produced by.........overdriven stages
Harmonic of a particular frequency (the fundamental frequency f) is a frequency that is an integer multiple of the first one. For example: If f (fundemental frequency) = 125 MHz, the harmonics would be [Information]
1st harmonic = 1 x f = 125 MHz
2nd harmonic = 2 x f = 250 MHz
3rd harmonic = 3 x f = 375 MHz
4th harmonic = 4 x f = 500 MHz etc
In radioteletype transmission, either ASCII or ________ is used
cw
teletype
Baudot
digital
Signal-to-Noise (SNR) : [Information]
SNR is defined as the ratio of signal power to the noise power, often expressed in decibels. A ratio higher than 1:1 (greater than 0 dB) indicates more signal than noise.It may be expressed as power or voltage
The noise performance and hence the signal to noise ratio is a key parameter for any radio receiver.
The SNR as it is often termed is a measure of the sensitivity performance of a receiver.
Phase modulation (PM) : [Information]
Is produced by a reactance modulator connected to an RF power amplifier
Phase modulation is a modulation pattern for conditioning communication signals for transmission. It Encodes a message signal as variations in the instantaneous phase of a carrier wave
Phase modulation (PM) is a modulation pattern for conditioning communication signals for transmission. It encodes a message signal as variations in the instantaneous phase of a carrier wave. Phase modulation is one of the two principal forms of angle modulation, together with frequency modulation.
Phase modulation (PM) is a method of impressing data onto an alternating-current (AC) waveform by varying the instantaneous phase of the wave. This scheme can be used with analog or digital data. In analog PM, the phase of the AC signal wave, also called the carrier, varies in a continuous manner.
Half-power points are also known as ____
3 db points
6 db points
9 db points
12 db points
Amplitude modulation telephony (voice), double sideband is _____
J3E
R3E
A3E
H3E
Amplitude modulation telephony (voice), single side band with suppressed carrier is ____
H3E
R3E
J3E
C3F
Frequency modulation telephony (voice) is _______
F1A
F2D
F3C
F3E
Telegraphy (CW) (on-off keying) without modulation by an audio frequency is ____
A1A
N0N
A2A
A3E
1) The root-mean-square (RMS) value of a sine wave form is equal to: 2) The average value of a sine wave of voltage or current is :
1) 0.707 of its peak value of the wave
2) 0.637 times the peak value.
What is the ratio of unmodulated carrier power to instantaneous peak power at 100% modulation?
40 percent
30 percent
25 percent
20 percent
What is the operating frequency of the transceiver if the radio wave is 6 meters long?
40 MHz
50 MHz
60 MHz
70 MHz
Ratio of maximum deviation allowed to the modulating frequency is
Radioteletype (RTTY) is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations connected by radio rather than a wired link.
Audio frequency-shift keying (AFSK) is a modulation technique by which digital data is represented by changes in the frequency (pitch) of an audio tone, yielding an encoded signal suitable for transmission via radio or telephone.
Frequency-shift keying (FSK) is a frequency modulation scheme in which digital information is transmitted through discrete frequency changes of a carrier signal
Mark and space are terms describing logic levels in teleprinter circuits
The frequency bands normally used for the line of sight (LOS) propagation :
300-3000 MHz
30 Hz – 30 kHz
30-300 MHz
30-300 GHz
Second harmonic of 500 kHz
500 kHz
1000 kHz
1500 kHz
2000 kHz
Two forms of angle modulation are frequency modulation and ________ modulation
phase
amplitude
digital
under
F3 emission means carrier is
amplitude modulated by voice
frequency modulated by voice
carrier modulated by voice
side band modulated by voice
Double-sideband (DSB) Modulation
The modulation in which modulated output signal contains two side bands of frequencies. The signal content located below the carrier frequency is called lower side band frequency and the signal content located above the carrier frequency is called upper side band frequency.
Amplitude (AM) Modulation
Is a modulation technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. In amplitude modulation, the amplitude (signal strength) of the carrier wave is varied in proportion to that of the message signal being transmitted.
Single-Sideband (SSB) modulation
or single-sideband suppressed-carrier modulation is a type of modulation, used to transmit information, such as an audio signal, by radio waves.
A refinement of amplitude modulation, it uses transmitter power and bandwidth more efficiently.
Bandwidth
Bandwidth is the total range of frequency required to pass a specific signal that has been modulated to carry data without distortion or loss of data.
Radiation occurring on frequencies which are whole multiple of the original desired frequency is called
fundamental
parasitic
reference
harmonic
Undesired oscillations developed in a radio frequency amplifier circuit at some frequency are called
particles
neutronic
frequent
parasitic
Signal to Noise ratio : [Information]
Signal-to-noise ratio is the ratio of the strength of a signal to its background noise.
In analog and digital communications, signal-to-noise ratio, often written S/N or SNR, is a measure of signal strength relative to background noise. The ratio is usually measured in decibels (dB) using a signal-to-noise ratio formula.
When an audio component lists a signal-to-noise ratio of 100 dB, it means that the level of the audio signal is 100 dB higher than the level of the noise. A signal-to-noise ratio specification of 100 dB is considerably better than one that is 70 dB (or less).
Frequency range between two half-power points is
wavewidth
signalwidth
bandwidth
modwidth
The 2nd harmonic of the frequency of one meter ?
0.50 meter
1 meter
0.25 meter
2 meter
The sum of the carrier frequency and the sideband frequency of an amplitude modulated carrier signal
halfside bands
upperside bands
lowerside bands
fullside bands
If you decrease the percentage of modulation from 100% to 50%, by what % have you decreased the power in the sidebands?
25
30
35
40
A frequency band most suitable for groundwave propagation
HF
VHF
MF
UHF
SSB Modulation is classified as
Amplitude
Balanced
Frequency
Carrier
Polarization of a directional antenna used in high frequency (HF) propagation is normally
vertical
ground
horizontal
sky
Balanced modulator is a device used to
nulify the carrier in SSB transmitter
increase the carrier in SSB transmitter
suppress the carrier in SSB transmitter
adjust the carrier in SSB transmitter
What is the usual bandwidth of a frequency-modulated amateur signal?
Less than 5 kHz
Between 5 and 10 kHz
Between 10 and 20 kHz
Greater than 20 kHz
Another name for indirect FM
voice modulation
amplifier modulation
phase modulation
balance modulation
To avoid fading of signals especially in UHF or VHF transmission, this technique is used
Frequency modulation
Frequency diversity
Frequency reactance
Frequency amplitude
Ratio of maximum deviation allowed to the modulating frequency is a
Frequency deviation
Frequency ratio
Frequency peak
Frequency bandwith
A device used to remove one sideband from a double sideband signal
Band pass filter
Low pass filter
High pass filter
Medium pass filter
Polarization of VHF whip antenna :
Circular
Horizontal
Vertical
None of the above
Peak envelope power (PEP) : [Information]
Peak envelope power is the highest envelope power supplied to the antenna transmission line by a transmitter during any full undistorted RF cycle or series of complete radio frequency cycles
If a single-sideband phone transmitter is 100% modulate, a speech processor will increase the output PEP
For HF or SSB propagation, frequency band used is
3-30 MHz
30-300 MHz
30-300 KHz
300-400 MHz
If the radio wave is 10 meters long, the frequency is____
20 MHz
30 MHz
40 Mhz
50 MHz
Key Clicks : [Information]
Key clicks are generally undesired "clicks" or "thumps" generated by a CW transmitter as the key is put down or let up.
Key-clicks, heard from a Morse code transmitter at a distant receiver, are the result of........too sharp rise and decay times of the carrier
Key-clicks can be suppressed by.........inserting a choke and a capacitor at the key
In a Morse code transmission, local RF interference (key-clicks) is produced by.....poor shaping of the waveform
Sine, Square and Sawtooth wave forms: [Information]
Sine Wave (or “Sinusoidal wave”) is the purest wave that contains only the fundamental frequency. A sine wave can be considered the most fundamental building block of sound.
Square Wave is a waveform that quickly rises to a particular level, remains constant for some period, then instantly drops to another level and stays there, and finally, rises to its original level to complete the wave cycle. The square wave differs from the sinusoidal wave in that besides the fundamental frequency it also contains odd harmonics. This waveform has a rich and pretty “raspy” sound.
Sawtooth Wave is a waveform that rises from a zero value to a peak value and then quickly drops to a zero value, for each cycle. The result looks like the teeth of a saw (hence the name). Sawtooth wave contains a significant amount of even harmonics, unlike many of the other waveforms, produced by common VCOs. The result is bright, loud and “brassy” sound.
Communication involving distress should not exceed ...... words per minute (wpm)
5 wpm
8 wpm
12 wpm
16 wpm
The basic single sideband demodulator is known as
metal dectector
balanced detector
amplitude detector
product detector
The FM modulation index : [Information]
The FM modulation index is equal to the ratio of the frequency deviation to the modulating frequency......Frequency deviation / (divided by) Modulation frequency
FM modulation index.... The signal has a frequency deviation of ±5kHz, and the modulating frequency is 1kHz, then the modulation index for this particular instance is 5 / 1 = 5.
Modulation index = peak deviation ÷ max audio frequency = 2.5kHz ÷ 3 kHz = 0.8
Frequency Modulation Deviation : [Information]
The amount of change in the carrier frequency produced, by the amplitude of the input modulating signal, is called frequency deviation.
FM deviation ratio can be defined as: the ratio of the maximum carrier frequency deviation to the highest audio modulating frequency.....m = maximum frequency deviation / (divided by) maximum modulation frequency....Example a broadcast station maximum frequency deviation is ±75 kHz, and the maximum audio frequency for the modulation is 15 kHz......Using the formula above, this means that the deviation ratio is 75 / 15 = 5.
What type of filter might be connected to an amateur HF transmitter to cut down on harmonic radiation?
A CW filter
A low pass filter
A high pass filter
A key-click filter
What is the usual bandwidth of a single side band amateur signal?
1 khz
2 khz
Between 2 and 3 khz
Between 3 and 6 khz
Modulation is defined as the process whereby some characteristic (line amplitude, frequency, phase of a high frequency signal wave (carrier wave) is varied in accordance with instantaneous value intensity of low frequency signal wave (modulating wave.)There a 3 types of modulation: [Information]
Amplitude modulation
Frequency modulation
Phase modulation
In a Morse code transmission, local RF interference (key-clicks) is produced by:
shift in frequency when keying the transmitter
sparking at the key contacts
sudden movement in the receiver loudspeaker
poor shaping of the waveform
What is LSB (lower side band) and USB (upper side band) ?
Most voice signals on HF are SSB, so you have to choose between USB upper sideband (USB) and lower sideband (LSB). The actual SSB signals extend in a narrow band above (USB) or below (LSB) the carrier frequency displayed on the radio.
Frequencies for LSB and USB in amateur radio voice communication.
When single-sideband is used in amateur radio voice communications, it is common practice that for frequencies below 10 MHz, lower sideband (LSB) is used and for frequencies of 10 MHz and above, upper sideband (USB) is used.
Which of the following phone emissions uses the narrowest frequency bandwidth?
Phase Modulation
Frequency modulation
Single sideband
Double sideband
Chirp : [Information]
A chirp is a signal in which the frequency increases (up-chirp) or decreases (down-chirp) with time"Chirp" is a change in frequency when the transmitter is keyed on ( by pressing the Morse key) and keyed off ( the release of the Morse key ) when the Morse characters are being formed. - thus the change in frequency would be heard on a receiver at the start and end of each keying stroke
Causes of chirp include:DC Instability caused by poor voltage regulation.....Keep the power supply voltages very steady under transmit load.
RF Feedback getting back into the frequency determining stage (oscillators)....... Greater attention to the detail of screening leads carrying RF and keeping leads as short as possible and the use of decoupling capacitors on the power lines.
A change in frequency of Morse code from the desired frequency, due to poor stability in the RF oscillator, is known as chirp and in the R-S-T system is given an appended letter 'C'.
Backwave : [Information]
Back Wave (or Spacer Wave) is the small signal often radiated during key-up condition. It is common for the back wave to be audible in the own station receiver, but this does not mean that it is radiated far..... If an appreciable spacer is radiated , it would make a signal difficult to copy......Causes are....(a)The keyed transmitter stage not being completely cutoff.....(b) Leakage of RF through the power amplifier valve capacitance.
Backwave is a condition in which the signal is heard at a reduced level, even when the key is up. This occurs when the oscillator signal feeds through a keyed amplifier.
Backwave is undesirable because it makes a signal harder to copy.
Envelope:
The envelope of an oscillating signal is a smooth curve outlining its extremes...The envelope thus generalizes the concept of a constant amplitude... The figure illustrates a modulated sine wave varying between an upper and a lower envelope... The envelope function may be a function of time, space, angle, or indeed of any variable.
UHF frequency falls within the band
3-30 Mhz
30 Hz – 30 kHz
300-3000 MHz
3-30 GHz
Overmodulation: [Information]
Overmodulation is the condition that prevails in telecommunication when the instantaneous level of the modulating signal exceeds the value necessary to produce 100% modulation of the carrier.
Q : What is the effect of overmodulation? A : Excessive bandwidth
What causes splatter interference?
The transmitting antenna is the wrong length
Keying a transmitter too fast
Overmodulation of a transmitter
High swr
Waveform : [Information]
A waveform is a variable that varies with time, usually representing a voltage or current.
Waveforms are conventionally graphed with time on the horizontal axis.
In electronics, an oscilloscope can be used to visualize a waveform on a screen. A waveform can be depicted by a graph that shows the changes in a recorded signal's amplitude over the duration of recording
Bandwidth: [Information]
The bandwidth of an RF signals is the range of frequencies used to carry information. It is a range of radio frequencies transmitted or received for which the power is not zero
CW bandwidth typically 100–150 Hz. SSB bandwidth is about 3 kHz wide
AM bandwidth is about 6 kHz wide FM signal bandwidth varies from about 10 kHz to 15 kHz
Narrow-band voice modulation: [Information]
Narrowband is a telecommunication that carries voice information in a narrow band of frequencies
Narrowband signals are used in a slower form of communication where mainly voice or slow datastreams have to be transmitted
Narrowband signals usually have a far greater range of reception as narrower filters can be used and therefore cancel out unwanted wideband noise
Ideal value of signal to noise ratio ?
infinity
negative
positive
zero
Pulse Modulation : [Information]
A type of modulation in which pulses are varied in some respect, such as width or amplitude, to represent the amplitude of a signal.
Pulse modulation is a technique in which the signal is transmitted with the information by pulses. This is divided into Analog Pulse Modulation and Digital Pulse Modulation.
Pulse Width Modulation (PWM):The pulse width modulation is the modulation of signals by varying the width of pulses. The amplitude and positions of the pulses are constant in this modulation
Pulse Position Modulation (PPM):The pulse position modulation is the modulation of signals by varying the position of pulses. The amplitude and width of the pulses are constant in this modulation.
Electromagnetic (EM) radiation : [Information]
Electromagnetic (EM) radiation is a form of energy that is all around us and takes many forms, such as radio waves, microwaves, X-rays and gamma rays.
Electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space, carrying electromagnetic radiant energy.It includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays
Wave Polarization :
Polarization, also called wave polarization, is an expression of the orientation of the lines of electric flux in an electromagnetic field ( EM field ). ... Thus, a vertical antenna receives and emits vertically polarized waves, and a horizontal antenna receives or emits horizontally polarized waves.
Information rate v Bandwidth : [Information]
Information rate. A formula for measuring the amount of information received by multiplying the amount of information content for each character by the number of characters that are being transmitted every second.
Bandwidth (signal processing) or analog bandwidth, frequency bandwidth or radio bandwidth, a measure of the width of a range of frequencies, measured in hertz (Hz)
Bandwidth (computing), the rate of data transfer, bit rate or throughput, measured in bits per second (bit/s)
Megabits per second (Mbps) are a unit of measurement for bandwidth and throughput on a network.
Amateur Frequency Bands : [Information]
ITU : Amateur radio frequency allocation is done by national telecommunication authorities. Globally, the International Telecommunication Union (ITU) oversees how much radio spectrum is set aside for amateur radio transmissions. Individual (licensed) amateur stations are free to use any frequency within authorized frequency ranges; authorized bands may vary by the class of the station license.
The International Amateur Radio Union (IARU) is an international confederation of national amateur radio organisations that allows a forum for common matters of concern and collectively represents matters to the International Telecommunication Union (ITU).
Philippines is in IARU Region 3 (R3)
Signal Information : [Information]
The signals carry the information through the system from one point to another. The signals are either digital or analog, depending on their location within the system.
The Signals, Information and Data area concerns the representation, processing, analysis, and communication of information embedded in signals and datasets arising in a wide range of application areas, including audio, video, images, communications, and biology.
Digital Signals :
A digital signal refers to an electrical signal that is converted into a pattern of bits. Unlike an analog signal, which is a continuous signal that contains time-varying quantities, a digital signal has a discrete value at each sampling point.
How can you prevent key-clicks ?
By increasing power
By using a key-click filter
By sending CW more slowly
By using a better power supply
Superimposed Hum : [Information]
Modulation Hum : Something close to your radio's antenna is picking up the strong short wave signal and rebroadcasting it with power-line frequency hum superimposed.
Ground loops will cause hum, buzzes,and other noises, especially when connected to computerized gear or lighting equipment.
If a 10 kHz tone is transmitted and the modulation index is 7.5, what is value of maximum deviation?
65 khz
70 khz
75 khz
80 khz
Intermediate frequency (IF) amplifier and Radio Frequency (RF) amplifier. [Information]
IF amplifier is a linear fixed-frequency tuned amplifier, found in the IF stage of a super-heterodyne radio receiver
The intermediate frequency is the difference between the incoming carrier frequency and the oscillator frequency.
A radio frequency power amplifier (RF power amplifier) is a type of electronic amplifier that converts a low-power radio-frequency signal into a higher power signal. Typically, RF power amplifiers drive the antenna of a transmitter.
Root Mean Square : [Information]
RMS value. RMS value of an AC voltage/current is equivalent to the DC voltage/current that produces the same heating effect when applied across an identical resistor. For example, a lamp connected to a 6V RMS AC supply will shine with the same brightness when connected to a steady 6V DC supply.
The r.m.s. voltage of an a.c. signal is always less than peak voltage because the peak voltage only occurs twice in the cycle (one positive one negative, during the rest of the cycle). At other times it is less.
The rms value is 0.707 times the peak value, and the peak value is 1.41 times the value the voltmeter shows (see D).
The peak value for 230 V AC mains supply is 325 V that is 230v x 1.41 = 324.3 V (325 V)
The RMS value for 325 V is 229.7 V that is 325 V x 0.707 = 229.7 V (230 V)
Most multi-meters, either voltmeters or ammeters, measure RMS value assuming a pure sinusoidal waveform.
Frequency Modulation (FM : F3E) [Information]
Frequency Modulation : Deviation of carrier output frequency is proportional to amplitude of modulating signal. Amplitude of carrier constant.
Narrow band FM, NBFM, is used for signals where the deviation is small enough that the terms in the Bessel function is small and the sidebands are negligible. For this the FM modulation index must be less than 0.5, although a figure of 0.2 is often used. For NBFM the audio or data bandwidth is small, but this is acceptable for this type of communication.
Wideband FM is typical used for signals where the FM modulation index is above 0.5. For these signals the sidebands beyond the first two terms are not insignificant. Broadcast FM stations use wideband FM which enables them to transmit high quality audio, as well as other facilities like stereo, and other facilities like RDS, etc..
Transmission duty cycle 100%
Single Side Band (SSB - J3E) [Information]
Single Side Band (Amplitude Modulation) :Carrier is suppressed, generally by a balanced modulator
Information in both sidebands of an AM wave is identical so one sideband is suppressed, generally by a filter......Bandwidth equals that for speech – about 2.6kHz
Suppressed carrier, all power in sideband so more efficient, and no “beats” or heterodyne whistles
Transmission duty cycle 20% rising to 40% with speech processing
Amplitude Modulation Index [Information]
Amplitude Modulation Index is the ratio m=Vm/Vc....Where Vm is the amplitude voltage of modulating (Information) signal and Vc is the amplitude voltage of carrier signal....Multiplying the ratio of modulation index by 100 gives the percentage modulation m=Vm/Vc*100......For example, if the carrier voltage is 8 V and the modulating (information) signal voltage is 6.5 V, then the modulation index will be Vm/Vc = 6.5/8 = 0.8125 x 100 gives a modulation percentage of 81.25%
A Modulation Index of 0.90 means that the signal will increase by a factor of 0.90 and also decrease to 0.10 of its original level. The modulation index is a ratio and hence the modulation index should be a number between 0 and 1.......If the amplitude of the information signal voltage is higher than the carrier voltage, m will be greater than 1, causing distortion in AM wave.
If the carrier signal amplitude is 5 volts then the message signal amplitude must be less than 5 volts....... If modulation index is higher than 1, then it is called overmodulation. In overmodulation, the data loss will occur. When modulation index is expressed in percentage, it is also called percentage modulation.
Modulation is the process of encoding information from a message source in a way that is suitable for transmission. This is achieved by altering the characteristics of a (Carrier) wave. By superimposing a message on to a high frequency signal known as a carrier wave (or sinusoidal signal), video, voice and other data can be transmitted.
Bandwidth : Throughput : Date Rate : Bits per Second : [Information]
Bandwidth is the measurement of the ability of an electronic communications device or system to send and receive information and is the amount of data that can be transferred at one time....Typically, bandwidth is expressed as a bitrate and measured in bits per second (bps).
Throughput is the amount of data moved successfully from one place to another in a given time period, and typically measured in bits per second (bps), as in megabits per second (Mbps) or gigabits per second (Gbps)....Throughput also refers to the actual number of data packets that get transmitted.
Data rate is the speed at which data is transferred between two devices, measured in mega bits per second (Mbps or mbps) while.....Data Rate Transfer : The speed with which data can be transmitted from one device to another. Data rates are often measured in megabits (million bits) or megabytes (million bytes) per second. These are usually abbreviated as Mbps and MBps,respectively.
Bits per second....bps Kilobits per second....kbps Megabits per second....Mbps Gigabits per second....Gbps To convert say 10 Megabytes to Megabits......Since there is 1 byte for every 8 bits.....multiply by 8......10 x 8 = 80...there are 80 Megabits in 10 Megabytes.
Speech Processor [Information]
Speech processing (or speech compression) ....... is a method of boosting the average output power when operating SSB....... A speech processor takes a normal voice signal, which varies constantly as you speak, and processes the signal to minimize fluctuating power levels..... The result is an SSB signal that has consistent power at the highest level possible......Speech processing is good when you are operating at low power or with a poor antenna.
Speech processing can distort the signal.....An incorrectly adjusted speech processor can result in 1) Distorted speech....2) Splatter....3) Excessive background pickup.
If your transmitter sends signals outside the band where it is transmitting, what is this called?
Transmitter chirp
Off-frequency emissions
Spurious emissions
Side tones
All amateur stations, regardless of the mode of transmission used, must be equipped with:
a dc power meter
dummy antenna
a reliable means for determining the operating radio frequency
an overmodulation indicating device
Parasitic oscillations in a RF power amplifier can be suppressed by:
pulsing the supply voltage
placing suitable chokes, ferrite beads or resistors within the amplifier
screening all input leads
using split-stator tuning capacitors
An interfering signal from a transmitter has a frequency of 57 MHz. This signal could be the:
seventh harmonic of an 80 meter transmission
third harmonic of a 15 metre transmission
second harmonic of a 10 metre transmission
crystal oscillator operating on its fundamental
The output power rating of a linear amplifier in a SSB transmitter is specified by the: