CRAC Class C (2025) — Questions 161–170
U0204. The principles for amateur stations using amateur-service frequencies are: (Choose all that apply.)
业余无线电台使用业余业务频率使用原则：
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When using amateur-service frequencies, an amateur station needs no radio-frequency use license and is exempt from frequency occupancy fees (A, B). C and D are the opposite of the preferential treatment granted to amateur radio.
U0205. The lowest band allocated by our country's Radio Frequency Allocation Regulations to the amateur service is 135.7–137.8 kHz; this belongs to the following radio-spectrum band (waveband):
我国《无线电频率划分规定》划分给业余业务使用的最低频段 为135.7-137.8kHz，属于无线电频谱的下列频段（波段）：
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135.7–137.8 kHz lies in the low-frequency (低频/LF, also called 长波 long wave) band, 30–300 kHz (A). VLF is 3–30 kHz, so B is wrong; C/D are not standard amateur-designated bands here.
U0206. The 1,800 kHz–2,000 kHz allocated by our country's Radio Frequency Allocation Regulations to the amateur service belongs to the following radio-spectrum band (waveband):
我国《无线电频率划分规定》划分给业余业务使用的 1,800kHz-2,000kHz属于无线电频谱的下列频段（波段）：
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1800–2000 kHz (the 160 m band) is in the medium-frequency (中 频/MF, 中波 medium wave) range, 300 kHz–3 MHz (A). LF is below 300 kHz and HF starts at 3 MHz, so C/D are wrong; B is VHF which is far higher.
U0207. The 28 MHz–29.7 MHz allocated by our country's Radio Frequency Allocation Regulations to the amateur service belongs to the following radio-spectrum band (waveband):
我国《无线电频率划分规定》划分给业余业务使用的28MHz- 29.7MHz属于无线电频谱的下列频段（波段）：
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28–29.7 MHz (the 10 m band) is in the high-frequency (高频/HF, 短 波 short wave) range, 3–30 MHz (A). MF is below 3 MHz and VHF starts at 30 MHz, so B/C/D are wrong.
U0208. The 50 MHz–54 MHz allocated by our country's Radio Frequency Allocation Regulations to the amateur service belongs to the following radio-spectrum band (waveband):
我国《无线电频率划分规定》划分给业余业务使用的50MHz- 54MHz属于无线电频谱的下列频段（波段）：
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50–54 MHz (the 6 m band) is in the very-high-frequency (甚高 频/VHF, 米波 metric wave) range, 30–300 MHz (A). HF is below 30 MHz; UHF/SHF are above 300 MHz, so B/C/D are wrong.
U0209. The band allocated by our country's Radio Frequency Allocation Regulations to the amateur service that is closest to the wireless broadband WiFi frequency, 2,300–2,450 MHz, belongs to the following radio-spectrum band (waveband):
我国《无线电频率划分规定》划分给业余业务使用的最接近无 线宽带WiFi 频率的频段为2,300-2,450MHz，属于无线电频谱 的下列频段（波段）：
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2300–2450 MHz (the 2.3 GHz / 13 cm amateur band, near WiFi/ISM) is in the ultra-high-frequency (特高频/UHF, 分米波 decimetric wave) range, 300 MHz–3 GHz (A). VHF is below 300 MHz and SHF (厘米波) starts at 3 GHz, so B/D are wrong; C is HF.
U0210. The 430–440 MHz amateur band is closest to the operating frequencies of public walkie-talkies (citizen-band radios). If an amateur wishes to modify the amateur station configuration to "extend" it and communicate with public walkie-talkie users, they should note:
430-440MHz业余频段与公众对讲机的工作频率最为接近。如 果业余无线电爱好者希望通过改变业余电台的配置，将之"扩 频"并与公众对讲机持有者通信，则需注意：
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An amateur station may only communicate within the amateur service; communicating with public walkie-talkie (citizen-band) users is outside the amateur service and is prohibited (A). B/C/D all wrongly assume such cross-service communication is permissible under some power limit.
U0211. The band allocated by our country's Radio Frequency Allocation Regulations to the amateur service that is closest to the WiFi LAN frequency, 2,300–2,450 MHz, belongs to the following radio- spectrum band:
我国《无线电频率划分规定》划分给业余业务使用的最接近Wi- Fi局域网频率的频段为2,300-2,450MHz，属于无线电频谱的下 列频段（波段）：
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2300–2450 MHz is UHF (ultra high frequency, 300 MHz–3 GHz) (A). VHF is below 300 MHz, HF below 30 MHz, and SHF starts at 3 GHz.
U0212. The band allocated by our country's Radio Frequency Allocation Regulations to the amateur service that is closest to the C-band satellite TV broadcast frequency, 5.650–5.850 GHz, belongs to the following radio-spectrum band (waveband):
我国《无线电频率划分规定》划分给业余业务使用的最接近C波 段卫星电视广播频率的频段是5.650-5.850GHz，属于无线电频 谱的下列频段（波段）：
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5.65–5.85 GHz (the 5 cm amateur band) is in the super-high- frequency (超高频/SHF, 厘米波 centimetric wave) range, 3–30 GHz (A). UHF ends at 3 GHz and EHF starts at 30 GHz, so B/C/D are wrong.
U0213. The band allocated by our country's Radio Frequency Allocation Regulations to the amateur service that is closest to the Ku-band satellite TV broadcast frequency, 10–10.5 GHz, belongs to the following radio-spectrum band (waveband):
我国《无线电频率划分规定》划分给业余业务使用的最接近Ku 波段卫星电视广播频率的频段10-10.5GHz，属于无线电频谱的 下列频段（波段）：
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10–10.5 GHz (the 3 cm amateur band) is SHF (超高频/厘米波, 3–30 GHz) (A). UHF ends at 3 GHz and EHF begins at 30 GHz, so B/C/D are wrong.