CRAC Class B (2025) — Questions 161–170
U0166. The correct statement about the use of amateur frequencies is:
关于业余频率的使用，正确的叙述是：
Exam tips · 考试提示
Within the bands that the radio management authority has approved for a station's use, all amateur stations enjoy equal frequency-use rights (A). B is too broad (not "any band"); C wrongly implies class-based priority; D wrongly implies association/club priority. No amateur station outranks another on an amateur frequency.
U0167. In the Table of Frequency Allocations, when a band is allocated to the amateur service or amateur-satellite service together with several other services, and the amateur service and amateur- satellite service are secondary services, the rule an amateur radio station must follow is:
在频率划分表中，当一个频段划分给业余业务或卫星业余业务 和多个其他业务，并且业余业务和卫星业余业务作为次要业务 时，业余无线电台应该遵循的规则是：
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The fundamental secondary-service obligation is that the amateur station must not cause harmful interference to primary-service stations (A). B is wrong — a secondary service may not claim protection from primary users. C is also wrong here: a secondary service may claim protection from other secondary/same-service stations, so the statement "may not claim protection" is false. D is plainly prohibited — no interference is ever permitted.
U0168. In the Table of Frequency Allocations, when a band is allocated to the amateur service or amateur-satellite service together with several other services, and the amateur service and amateur- satellite service are secondary services, the rule an amateur radio station follows is:
在频率划分表中，当一个频段划分给业余业务或卫星业余业务 和多个其他业务，并且业余业务和卫星业余业务作为次要业务 时，业余无线电台遵循的规则是：
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This is the other half of the secondary-service rule: a secondary service must not claim protection from harmful interference by primary-service stations (A). B is the negation and is wrong. C is wrong because a secondary service may claim protection from other secondary/same-service stations. D is always prohibited.
U0169. The frequency bands allocated by our country exclusively to the amateur service and amateur-satellite service are:
我国分配给业余业务和卫星业余业务专用的频段有：
Exam tips · 考试提示
The bands China allocates exclusively (专用) to the amateur service are 7 MHz, 14 MHz, 21 MHz, 28 MHz, and 47 GHz (A). 144 MHz and 430 MHz are shared (not exclusive), so B and D are wrong; 3.5 MHz is a shared primary band and 10 GHz is not in this exclusive list, so C is wrong.
U0170. The bands below 30 MHz that our country allocates for shared use between the amateur service (and amateur-satellite service) and other services, with the amateur service as one of the primary services, are:
我国分配给业余业务和卫星业余业务与其他业务共用、并且业 余业务和卫星业余业务作为主要业务之一的30MHz以下频段 有：
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Below 30 MHz, the shared bands where amateur is one of the primary services include 1.8 MHz, 3.5 MHz, 14.25 MHz, 18.068 MHz, and 24.89 MHz (A). B wrongly includes 7 MHz (exclusive) and 21 MHz (exclusive); C/D include 10.1 MHz which is a WARC band allocated as a secondary/shared category, not a shared-primary band in this listing.
U0171. In the VHF and UHF range, our country allocates the amateur service (and amateur-satellite service) for shared use with other services under both primary and secondary categories. Which of the following frequencies are allocated for shared use with other services where the amateur service is a primary service:
我国在VHF和UHF范围内分配给业余业务和卫星业余业务与其 他业务共用并设业务类别为主要业务与次要业务，以下那些频 率分配给业余业务和卫星业余业务与其他业务共用并且业余业 务和卫星业余业务作为主要业务：
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In VHF/UHF, 50 MHz and 144 MHz are allocated to amateur as a primary service sharing with others (A). 430 MHz is a secondary service, so any option containing 430 MHz (B, C, D) is wrong.
U0172. The number of bands our country allocates for shared use with other services where the amateur service is the sole primary service, and such a band below 3 GHz, are respectively:
我国分配给业余业务和卫星业余业务与其他业务共用、并且业 余业务和卫星业余业务作为唯一主要业务的频段的个数以及在 3GHz以下的该类频段分别为：
Exam tips · 考试提示
There are 3 bands where amateur is the sole primary among shared allocations; below 3 GHz one such band is 144–146 MHz (A). 7.0– 7.2 MHz and 50–54 MHz are exclusively amateur, and 28–29.7 MHz is exclusive, so B/C/D are wrong.
U0173. The bands below 1200 MHz that our country allocates for shared use where the amateur service is a secondary service are:
我国分配给业余业务和卫星业余业务与其他业务共用、并且业 余业务和卫星业余业务作为次要业务的1200MHz以下频段有：
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Below 1200 MHz, the secondary amateur allocations include 135.7 kHz, 5351.5 kHz, 10.1 MHz, and 430 MHz (A). 3.5 MHz and 7 MHz are primary/exclusive, 50 MHz and 144 MHz are primary, and 18.068 MHz / 24.89 MHz are shared-primary WARC bands — so B, C, and D are wrong.
U0174. The highest frequency band allocated by our country to the amateur service and amateur-satellite service, and its sharing category, are:
我国分配给业余业务和卫星业余业务的频率最高的频段及其共 用类别是：
Exam tips · 考试提示
The highest amateur allocation in China is 248–250 GHz, as the sole primary service (A). The other listed bands are lower in frequency, so B/C/D are wrong.
U0175. The international amateur community colloquially calls the three HF bands added to the amateur (and amateur-satellite) service by WARC-76 the "WARC bands"; their frequency ranges are:
国际业余无线电界把WARC-76增加分配给业余业务和卫星业余 业务的三个HF频段俗称为WARC频段，它们的频率范围是：
Exam tips · 考试提示
The three WARC-76 HF bands are 10.1–10.15 MHz, 18.068–18.168 MHz, and 24.89–24.99 MHz (A). The other options scramble the boundaries or swap digits.