Description : A disadvantage of using a trap antenna. A. It will radiate harmonics B. It can only be used for single-bad operation C. It is too sharply directional at lower frequencies D. It must be neutralized
Last Answer : A. It will radiate harmonics
Description : What Pythagoras discovered that to create the interval of a octave by stretching out two strings you need to play the second string using a ratio of 21.?
Last Answer : Need answer
Description : What is the tonal ratio of an octave? A. 1 to 2 B. 1 to 3 C. 2 to 1 D. 3 to 1
Last Answer : C. 2 to 1
Description : What is the interval for creating a perfect octave?
Last Answer : An octave is defined as two notes, one of which is twice thefrequency (vibrations per second) as the other; also two notes withan interval between them of 8 diatonic degrees.
Description : What is the interval for a perfect octave discovered by Pythagoras?
Last Answer : It is a doubling of the frequency.
Description : Stacking antenna elements A. increases sensitivity to weak signals B. will suppress odd harmonics C. decrease signal to noise ratio D. increases selectivity
Last Answer : A. increases sensitivity to weak signals
Description : In cellular system, _____ defines the geographic distance that is required between cells using identical frequencies in order to avoid interference between the radio transmissions at these cells. A. frequency-reuse ratio B. distance-to-reuse ratio (D/R) C. reuse format plan ratio D. reuse factor
Last Answer : B. distance-to-reuse ratio (D/R)
Description : A frequency of 3000 Hz has how many octaves above 1000 Hz? A. 1.6 octaves B. 2.1 octaves C. 1 octave D. 3 octaves
Last Answer : A. 1.6 octaves
Description : What octave bands are there in the midrange? A. 1st and 2nd B. 5th, 6th and 7th C. 3rd and 4th D. 8th and 9th
Last Answer : B. 5th, 6th and 7th
Description : Not a reason for the use of an antenna coupler. A. To make the antenna look resistive B. To provide the output amplifier with the correct load impedance C. To discriminate against harmonics D. To prevent re-radiation of the local oscillator
Last Answer : D. To prevent re-radiation of the local oscillator
Description : A modulation which does not follow the sine wave pattern, it produces undesirable harmonics such as spurious emission A. 0% modulated B. Over-modulated C. Unmodulated D. 100% modulated
Last Answer : B. Over-modulated
Description : What height of an ionized layer is determined from the time interval between the transmitted signal and the ionospheric echo at vertical incidence? A. Virtual height B. Apparent height C. Actual height D. Effective height
Last Answer : A. Virtual height
Description : It is an average power of a radio transmitter supplied to the antenna transmission line taken during a long sufficient interval of time and compared with the lowest frequency encountered in the modulation ... operating conditions. A. Carrier power B. Rated power C. Mean power D. Peak envelop power
Last Answer : C. Mean power
Description : A dielectric waveguide for the propagation of electromagnetic energy at light frequencies a. Stripline b. Microstrip c. Laser beam d. Fiber optics
Last Answer : d. Fiber optics
Description : Fiber optic cables operate at frequencies near a. 20MHz b. 200MHz c. 2GHz d. 800THz
Last Answer : d. 800THz
Description : In what range of frequencies are most omnidirectional horizontally polarized antennas used? A. VHF, UHF B. VLF, LF C. SH, EHF D. MF, HF
Last Answer : A. VHF, UHF
Description : How can multiple earth stations share a satellite on the same frequencies? A. Frequency reuse B. Multiplexing C. Mixing D. Frequency hopping
Last Answer : A. Frequency reuse
Description : Which of the following low noise transistors is commonly used at microwave frequencies? A. MOSFET B. GASFET C. MESFET D. JFET
Last Answer : C. MESFET
Description : Which of the following types of noise becomes of great importance at frequencies? A. Shot noise B. Random noise C. Impulse noise D. Transit-time noise
Last Answer : D. Transit-time noise
Description : Atmospheric noise becomes less severe at frequencies A. above 30 MHz B. below 30 MHz C. above 3000 kHz D. below 3000kHz
Last Answer : A. above 30 MHz
Description : Atmospheric noise or static is not a great problem A. at frequencies below 20 MHz B. at frequencies below 5 MHz C. at frequencies above 30 MHz D. at frequencies above 1 MHz
Last Answer : C. at frequencies above 30 MHz
Description : Which of the following frequencies is normally used for distress and safety communications? A. 4209.5 kHz B. 490 kHz C. 518 kHz D. 2174.5 kHz
Last Answer : D. 2174.5 kHz
Description : What is the channel spacing for SITOR frequencies? A. 500 Hz B. 170 Hz C. 300 Hz D. 3 kHz
Last Answer : A. 500 Hz
Description : What is the channel spacing for MF-HF voice frequencies? A. 2.8 kHz B. 500 Hz C. 3.5 kHz D. 3 kHz
Last Answer : D. 3 kHz
Description : The American concert pitch A is equivalent to which if the following frequencies? A. 440 Hz B. 435 Hz C. 260 Hz D. 255 Hz
Last Answer : A. 440 Hz
Description : A porous material is far more efficient at high than low frequency absorption. How to improve sound absorption at lower frequencies using this absorber? A. Increase the thickness B. Decrease the thickness C. Mount with and airspace behind D. Both A and C above
Last Answer : D. Both A and C above
Description : What noise is observable at frequencies in the range from about 8 MHz to somewhat 1.5 GHz? A. Industrial noise B. Atmospheric noise C. Space noise D. Shot noise
Last Answer : C. Space noise
Description : What device measures the angle between two radio frequencies and also the direction of propagation of a wave? A. Densimeter B. Absorption wavemeter C. Goniometer D. Ergometer
Last Answer : C. Goniometer
Description : When no signal is being received, the loudspeaker is not entirely silent as a result of the presence of A. parasitic oscillations in some of the receiver stages. B. negative feedback in each stage. C. spurious frequencies as a result of improper neutralization. D. internal receiver noise.
Last Answer : D. internal receiver noise.
Description : A 1 Mhz carrier is amplitude modulated by a pure 200-Hz audio test tone. Which of the following combinations of frequencies represent the total content of the AM signal? A. 1 MHz and 200 Hz B. 1 MHz and 1000.2 kHz C. 999.8 kHz, 1000 kHz, and 1000.2 kHz D. 999.8 kHz and 1000.2 kHz
Last Answer : C. 999.8 kHz, 1000 kHz, and 1000.2 kHz
Description : The band of frequencies least susceptible to atmospheric noise and interference is: A. 30 – 300 kHz B. 300 – 3000 kHz C. 3 – 30 MHz D. 300 – 3000 MHz
Last Answer : D. 300 – 3000 MHz
Description : What band of frequencies do these satellites operate? A. L band B. Ka band C. C band D. Ku band
Last Answer : A. L band
Description : Which band of frequencies used by military for its satellites and radar? A. C band B. X band C. L band D. P band
Last Answer : B. X band
Description : Frequencies above ______ kHz, are referred to as the radio frequencies. A. 20 B. 2 C. 10 D. 200
Last Answer : A. 20
Description : Electromagnetic waves of frequencies arbitrarily lower than 3,000 GHz, propagated in space without artificial guide. A. Space waves B. Terrestrial waves C. Mobile D. Hertzian waves
Last Answer : D. Hertzian waves
Description : Refers to a continuous tone generated in a local exchange terminal through a combination of two frequencies 350 Hz, and 440 Hz. A. Busy tone B. Call waiting tone C. Dial tone D. Standard tone
Last Answer : B. Call waiting tone
Description : What is the mixing process? A. Distortion caused by auroral propagation B. The combination of two signals to produce sum and difference frequencies. C. The elimination of noise in wideband receiver by phase differentiation D. The elimination of noise in a wideband receiver by phase comparison
Last Answer : B. The combination of two signals to produce sum and difference frequencies.
Description : Which of the following is designated as the international distress, safety and calling frequency for radio telephony for stations of the maritime mobile service when using frequencies in the authorized bands between 156 and 174 MHz? A. 165.8 MHz B. 156.8 MHz C. 158.6 MHz D. 168.5 MHz
Last Answer : B. 156.8 MHz
Description : Space diversity transmission means transmitting and receiving on _______. A. Two or more antennas operating on two different frequencies B. Two or more identical frequencies C. Two or more antennas operating on the same frequency D. Two or more different frequency
Last Answer : C. Two or more antennas operating on the same frequency
Description : Atmospheric noise is less at severe frequencies above A. Audio level B. 30 MHz C. 10 GHz D. 1 GHz
Last Answer : B. 30 MHz
Description : Emission on a frequency or frequencies immediately outside the necessary bandwidth which result from the modulation process except spurious emission. A. Radiation B. Noise C. Out of the band D. Interference
Last Answer : C. Out of the band
Description : Extra-terrestrial noise is observable at frequencies from A. 0 to 20 KHz B. Above 2 GHz C. 8 to 1.43 GHz D. 5 to 8 GHz
Last Answer : C. 8 to 1.43 GHz
Description : Fiber optic cable operates near _______ frequencies. A. 800 THz B. 20 MHz C. 200 MHz D. 2 GHz
Last Answer : A. 800 THz
Description : Space diversity transmission means transmitting and receiving on A. two or more antennas operating on two different frequencies B. two or more identical frequencies C. two or more different frequencies D. two or more antennas operating on the same frequencies
Last Answer : D. two or more antennas operating on the same frequencies
Description : Troposheric scatter uses the frequencies in the ________ band. A. VLF B. UHF C. VHF D. UF
Last Answer : B. UHF
Description : What is the method of diversity reception where the signal is transmitted on 2 different frequencies over the same path? A. Quadruple B. Frequency C. Polarization D. Space
Last Answer : B. Frequency
Description : One of the reasons why FDM is being replaced by TDM is A. noise is amplified with voice when an FDM system is used B. it is difficult to place channels side by side C. there is more time than frequency D. Most available frequencies has been used
Last Answer : A. noise is amplified with voice when an FDM system is used
Description : The ___________ filter attenuates signals but passes frequencies below and above that band. A. low pass B. band pass C. band stop D. high pass
Last Answer : C. band stop
Description : What does the noise weighting curve shows? A. Noise signals measured with a 144 handset B. Power levels of noise found in carrier systems C. The interfering effect of other frequencies in a voice ... a reference frequency of one kilohertz D. Interfering effects of signals compared with a 3-kHz tone
Last Answer : C. The interfering effect of other frequencies in a voice channel compared with a reference frequency of one kilohertz
Description : ECE Board Exam March 1996 Passive crossover components cause some frequencies to be delayed with respect to the other frequencies at the crossover point. A. Phase shift B. Phase correction C. Phase-error correction D. Time alignment
Last Answer : A. Phase shift