Amateur Radio Class b Element V

AMATEUR RADIO CLASS "B" EXAMINATION ELEMENT V PREPARED BY: HOMER M. ALBUFERA, 4F1KYW

1. To avoid fading of signals especially in UHF or VHF transmission, transmission, this technique is used A. B. C. D.

increase antenna height frequency diversity increase power use fixed antenna

2. Ratio of maximum deviation allowed to the modulating frequency is a A. B. C. D.

modulation ratio frequency deviation modulation deviation modulation index

3. If the 10 KHz tone is transmitted, and the maximum deviation is 75 KHz, the modulation index is A. B. C. D.

750 75 7.5 0.75

4. Phase modulation is called A. B. C. D.

pulse code direct FM indirect FM dual phase shift modulation

5. If the radiation resistance of the antenna is 50 ohms, the antenna current ampere, the radiated power is A. B. C. D.

250 W 10 W 1,250 W 1,250 KW

6. The most ideal SWR in VHF communications A. B. C. D.

infinite SWR very high SWR zero SWR unity SWR or 1:1 SWR

7. What circuit device is used to suppress the carrier in SSB transmitter A. B. C. D.

wave trap band-pass filter suppressor circuit balanced modulator

AMATEUR RADIO CLASS-B LEVEL V

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8. Device used for producing FM in a transmitter transmitter A. B. C. D.

balanced modulator frequency modulator reactance modulator lock modulator

9. Second harmonic of 500 KHz is A. B. C. D.

1,000 KHz 10,000 KHz 250 KHz 1,500 KHz

10. If the radio wave is 10 meters long, the frequency is (use formula A=300/Frequency in MHz A. B. C. D.

300 MHz 600 MHz 30 MHz 3 MHz

11. Two forms of angle modulation are frequency modulation band A. B. C. D.

pulse amplitude space phase modulation

12. F3 emission means carrier is A. B. C. D.

frequency modulated by on-off keying frequency modulated by phase shifting frequency modulated by voice frequency modulated by direct/data keying

13. For HF or SSB propagation, frequency band used is A. B. C. D.

300-3,000 KHz 3-30 MHz 30-300 MHz 3-30 GHz

14. To overcome difficulty in spelling, the A. B. C. D.

phonetic alphabet Q code ten code morse code


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15. When it is 10:00 AM in the Philippines, Philippines, what is it in UTC? A. B. C. D.

10 AM 0800 0200 0100 UTC

16. Which diodes are normally biased? A. B. C. D.

varactor bi-polar TRC zener

17. The symbol used for current amplication factor of transistors is A. B. C. D.

alpha beta gamma delta

18. A circuit element that opposes change in current A. B. C. D.

capacitor inductor resistor conductor

19. Radiation occurring on frequencies which are whole multiple of the original desired frequency is called A. B. C. D.

spurious harmonic intermode cross talk radiation

20. Undesired oscillation developed in a radio frequency amplifier circuit at some frequency higher than the normal operating frequency is called A. B. C. D.

sympathetic spurious parasitic operational oscillations

21. Polarization of VHF whip antenna A. B. C. D.

circular horizontal vertical dual polarization


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22. A device used to remove one sideband from a double sideband signal A. B. C. D.

balanced modulator reactance modulator multi-vibrator band pass filter

23. Ideal value of signal to noise ratio A. B. C. D.

unity zero infinity very small

24. Frequency range between two half-power points is A. B. C. D.

beamwidth bandwidth frequency limits beam angle

25. Root-mean-square (rms) value of a sine wave A. B. C. D.

50% 86.6% 70.7% 100%


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ANSWER KEY 1. frequency diversity 2. frequency deviation 3. 7.5 4. indirect FM 5. 1,250 W 6. unity SWR or 1:1 SWR 7. balanced modulator 8. reactance modulator 9. 1,000 KHz 10. 30 MHz 11. phase modulation 12. frequency modulated by voice 13. 3-30 MHz 14. phonetic alphabet 15. 0200 16. zener 17. beta 18. inductor 19. harmonic 20. parasitic 21. vertical 22. band pass filter 23. infinity 24. bandwidth 25. 70.7%


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Amateur Radio Class b Element V

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