Power, Band Edges and the 10 W Limit on a Standard Licence
Sam holds a standard amateur licence. He is testing a new HF dipole and wants to compare signal reports on 80 m, 40 m and 20 m. His amplifier can produce 400 W, and his licence class permits a maximum of 100 W for standard licensees on most bands, with some bands restricted further. He proposes to run 400 W on 3.600 MHz to 'get over the noise', then 100 W on 7.150 MHz, then 100 W on 14.150 MHz. He also plans to transmit on 7.100 MHz, which is outside the phone segment of the 40 m band plan, because a friend is listening there.
1. Evaluate Sam's proposed 400 W operation on 3.600 MHz against his licence conditions.
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It is not permitted. A standard licence carries a maximum transmitter output power, commonly 100 W for standard licensees, and 400 W exceeds that ceiling regardless of band or conditions. The desire to overcome noise does not create an exception. Sam should reduce power to within the limit, use better antenna efficiency or a lower-noise receiving setup, and consider that higher power on a crowded band increases interference risk. He should also verify the exact limit that applies to his licence class and to the band in question, because some bands are restricted further. Running 400 W would be a clear breach and could expose him to enforcement action.
2. Is Sam's plan to transmit on 7.100 MHz consistent with his obligations, even though it is within the 40 m band?
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Staying inside the band is necessary but not sufficient. Band plans allocate segments for different modes, and 7.100 MHz is outside the phone segment in the usual 40 m plan. Transmitting phone there could interfere with stations using the segment for other purposes and is contrary to the band plan. Sam should move his phone contact to the recognised phone segment, such as around 7.150 MHz, and check the current band plan for the exact limits. The reasoning is that licence conditions and band plans work together: being inside the authorised band does not authorise every mode on every frequency within it.
3. What should Sam do to compare the antenna lawfully across the three bands?
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He should keep output power within the limit for his licence class on each band, which for standard is commonly 100 W, and lower where a band is restricted further. He should choose frequencies within the correct mode segments of the band plan for 80 m, 40 m and 20 m, listen before transmitting, and identify properly. He should make comparisons under similar conditions, keep transmissions short, and avoid frequencies in use. He should also confirm that his transmitter is not producing excessive spurious emissions at the higher power he intends to use. The principle is that a valid comparison is possible within the rules by controlling power, frequency choice and operating practice.