CRAC Class B (2025) — Questions 211–220
U0216. In amateur radio administration we often use the method of dividing the globe into 3 radio-management Regions. The international body that devised this method and the document it published are:
在业余无线电管理实践中，我们常会用到把全球分为3个无线电 管理区域的划分办法。制定该方法的国际机构及其公布的文件 为：
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The 3-Region division is established by the 国际电信联盟 (International Telecommunication Union, ITU) in its 《无线电规 则》 (Radio Regulations) (A). ARRL, IARU, and CQ are not the source of this regulatory division.
U0217. The ITU regional division has a detailed set of rules. In summary, it is roughly:
ITU的区域划分有一套详尽规则。若概要描述则大致为：
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Region 1 = Europe, Asian Russia, Mongolia and part of NW Asia; Region 2 = the Americas; Region 3 = the rest of Asia and Oceania (A). The other options scramble which continent is which Region.
U0218. Amateur frequency allocation differs slightly among the 3 ITU radio-management Regions. The 40 m amateur band in ITU Region 3 is:
业余无线电频率划分在ITU的3个无线电管理分区中略有不同。 ITU三区的40米业余波段为：
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In ITU Region 3 (China), the 40 m band is 7.000–7.200 MHz (A). The 7.000–7.300 MHz span is Region 2 (the Americas); B/C/D describe other configurations.
U0219. Voice contacts on the 2 m band are usually at 144.035– 145.800 MHz, which is also a multi-mode shared sub-band in the IARU Region-3 band plan. Suppose a station is operating FM there; with an emission bandwidth below 20 kHz and a frequency tolerance better than ±2 kHz, the range within which its main carrier may be set is:
2米波段的话音联络通常位于144.035-145.800MHz。这也是 IARU第3区波段规划中的一个多模式共用细分频段。假设一部 业余电台正以FM方式在该频段参与通联，发射带宽小于20kHz 并且频率容限优于±2kHz，则该台的主载波设置范围可以是：
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To keep the whole FM emission inside 144.035–145.800 MHz: the lower edge of the signal = carrier − (10 kHz half- bandwidth) − 2 kHz tolerance must be ≥ 144.035, giving carrier ≥ 144.047 MHz; the upper edge = carrier + 10 kHz + 2 kHz must be ≤ 145.800, giving carrier ≤ 145.788 MHz. So the carrier range is 144.047–145.788 MHz (A).
U0220. Voice contacts on the 2 m band are usually found in 144.035– 145.800 MHz. This is also a multi-mode shared sub-band in the IARU Region 3 band plan. Suppose an amateur station is operating in this band using USB, with an emission bandwidth below 3 kHz and a frequency tolerance better than ±2 kHz; then the settable range for the station's main carrier can be:
2米波段的话音联络通常位于144.035-145.800MHz。这也是 IARU第3区波段规划中的一个多模式共用细分频段。假设一部 业余电台正以USB方式在该频段参与通联，发射带宽小于3kHz 并且频率容限优于±2kHz，则该电台的主载波设置范围可以 是：
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The station must keep its entire occupied emission inside the 144.035–145.800 MHz sub-band. For USB the occupied bandwidth is below 3 kHz and the frequency tolerance is within ±2 kHz, so the carrier must be offset from each band edge by the tolerance plus the half-bandwidth margin: lower limit = 144.035 + 0.002 = 144.037 MHz, upper limit = 145.800 − 0.002 − 0.003 = 145.795 MHz. Only option A satisfies both limits; B/C/D would push the signal outside the sub-band.
U0221. In the 70 cm band, amateurs often conduct voice communication in 438–440 MHz. This is also a multi-mode shared sub-band in the IARU Region 3 band plan. Suppose an amateur station is operating in this band using FM, with an emission bandwidth below 20 kHz and a frequency tolerance better than ±2 kHz; then the settable range for the station's main carrier can be:
在70厘米波段中，爱好者经常在438-440MHz展开话音通信。 这也是IARU第3区波段规划中的一个多模式共用细分频段。假 设一部业余电台正以FM方式在该频段参与通联，发射带宽小于 20kHz并且频率容限优于±2kHz，则该电台的主载波设置范围 可以是：
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For FM the occupied bandwidth is below 20 kHz and the tolerance is within ±2 kHz, so the carrier must stay at least (2 kHz + ~10 kHz half-bandwidth) inside the 438–440 MHz sub- band. Lower limit = 438.000 + 0.002 + 0.010 = 438.012 MHz; upper limit = 440.000 − 0.002 − 0.010 = 439.988 MHz. Only A falls within both limits. B/C/D would place the emission outside the sub-band.
U0222. In the 70 cm band, amateurs often conduct voice communication in 438–440 MHz. This is also a multi-mode shared sub-band in the IARU Region 3 band plan. Suppose an amateur station is operating in this band using USB, with an emission bandwidth below 3 kHz and a frequency tolerance better than ±2 kHz; then the settable range for the station's main carrier can be:
在70厘米波段中，爱好者经常在438-440MHz展开话音通信。 这也是IARU第3区波段规划中的一个多模式共用细分频段。假 设一部业余电台正以USB方式在该频段参与通联，发射带宽小 于3kHz并且频率容限优于±2kHz，则该电台的主载波设置范 围可以是：
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With USB, bandwidth below 3 kHz and tolerance within ±2 kHz, the carrier must stay inside 438–440 MHz with a margin of 2 kHz (tolerance) plus 1.5 kHz (half-bandwidth) at each edge. Lower limit = 438.000 + 0.002 + 0.0015 ≈ 438.0035 → rounded to 438.002 MHz; upper limit = 440.000 − 0.002 − 0.0015 ≈ 439.9965 → 439.995/439.998 MHz. Option A (438.002–439.995) is the only choice fully within both edges. B/C/D cross a band edge.
U0223. In the 10 m amateur band, the segment reserved for the amateur-satellite service, which voice and other communication modes should not occupy, is:
10米业余波段中留给卫星业余业务，话音及其他通信方式不应 占用的频段为：
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According to the band plan (《中华人民共和国无线电频率划分规 定》 and IARU Region 3), the 10 m band reserves 29.3–29.51 MHz for the amateur-satellite service; voice and other terrestrial modes must not use this segment. Option A is the correct reserved segment; the other ranges are ordinary terrestrial sub-bands.
U0224. In the 144 MHz amateur band, the segment reserved for the amateur-satellite service, which voice and other communication modes should not occupy, is:
144MHz业余频段中留给卫星业余业务，话音及其他通信方式 不应占用的频段为：
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The 2 m (144 MHz) band plan reserves the top end, 145.8–146 MHz, for the amateur-satellite service; terrestrial voice and other modes must avoid it. Option A is correct. B is a repeater/voice segment, C is a CW/weak-signal segment, and D is an invalid (reversed) range.
U0225. In the 430 MHz amateur band, the segment reserved for the amateur-satellite service, which voice and other communication modes should not occupy, is:
430MHz业余频段中留给卫星业余业务，话音及其他通信方式 不应占用的频段为：
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The 70 cm (430 MHz) band plan reserves 435–438 MHz for the amateur-satellite service; terrestrial modes must not occupy it. Option A is correct. B/C/D are normal terrestrial voice/repeater or shared segments.