CRAC Class B (2025) — Questions 201–210
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.
U0214. The highest band allocated by our country's Radio Frequency Allocation Regulations to the amateur service is 241 GHz–250 GHz, which 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高频段 为241GHz-250GHz，属于无线电频谱的下列频段（波段）：
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241–250 GHz is in the extremely-high-frequency (极高频/EHF, 毫米 波 millimetric wave) range, 30–300 GHz (A). SHF ends at 30 GHz, UHF at 3 GHz, and THF (至高频) begins above 300 GHz, so B/C/D are wrong. 无线电通信的一般规定与业余电台操作 2 C H A P T E R General Rules of Radio Communication and Operating Practice 本章讲解国际区域划分、CQ 呼叫与联络程序、Q 简语、发射类别、数字模式以及 DX / 竞赛操作规范。This chapter covers ITU regions, CQ calls and contact procedure, Q-codes, emission classes, digital modes, and DX/contest operating conventions. 国际无线电区域划分 International Radio Region Division
U0215. To divide radio frequencies worldwide, the International Telecommunication Union (ITU) Radio Regulations prescribe the following regional division:
为在世界范围内划分无线电频率，国际电信联盟《无线电规 则》规定了如下区域划分：
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The ITU Radio Regulations divide the world into 3 Regions for frequency planning, and China (along with most of Asia and Oceania) is in Region 3 (A). The other options describe fictitious region counts.