I'm building myself an Excel Cheat Sheet.
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1$\begingroup$ I presume that you're talking about regulations in the US, and I have edited the tags of your question accordingly. $\endgroup$– rclocher3Commented Aug 5, 2020 at 21:59
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2 Answers
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The ARRL's band chart (PDF) includes the maximum allowed power for stations in the United States and its territories. Sometimes the power limit depends on the license class of the operator and/or the band; in that case, the power limit is adjacent to the graphic for that license class and/or band. If no power limit is listed there, then the power limit is 1.5 kW, unless other restrictions apply. All power limits are measured as Peak Envelope Power (PEP) unless noted; the exceptions are the 2,200m and 630m bands, which specify Equivalent Isotropic Radiated Power (EIRP), and the 60m band, which specifies Effective Radiated Power (ERP). According to the chart, "Geographical and power restrictions may apply to all bands above 420 MHz."
According to Wikipedia, "PEP is normally considered the occasional or continuously repeating crest of the modulation envelope under normal operating conditions."
Wikipedia's definition of EIRP is, "the hypothetical power that would have to be radiated by an isotropic antenna to give the same ('equivalent') signal strength as the actual source antenna in the direction of the antenna's strongest beam." In other words, the EIRP is the PEP multiplied by the maximum gain of the antenna, where the gain is measured compared to an ideal isotropic antenna.
Wikipedia's definition of ERP is, "the total power in watts that would have to be radiated by a half-wave dipole antenna to give the same radiation intensity (signal strength or power flux density in watts per square meter) as the actual source antenna at a distant receiver located in the direction of the antenna's strongest beam (main lobe)." In other words, the ERP is the PEP multiplied by the maximum gain of the antenna, where the gain is measured relative to the maximum gain of a half-wave dipole, presumably in free space. I seem to recall that the maximum gain of a dipole in free space compared to an ideal isotropic antenna is +2.15 dB.
It should be mentioned that 47 CFR § 97.313 (a) says, "An amateur station must use the minimum transmitter power necessary to carry out the desired communications."
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$\begingroup$ It's one of the worst charts I've ever seen which is why I'm making my own. I guess I have to make one for each license class. $\endgroup$ Commented Aug 6, 2020 at 21:56
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1$\begingroup$ It's a good band chart, but not the best maximum power chart. I'd say you should post your chart here as an answer when you finish it, but this flavor of markup doesn't allow tables for some reason. $\endgroup$ Commented Aug 6, 2020 at 22:05
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In Part 97, of course. Specifically, section 97.313, "Transmitter Power Standards".
But of course it's not just per band... there are several limits that only apply to Novice license holders (none of those have been issued since 2000, but existing holders can still have them), one limit only applies to US territories outside of IARU Region 2 (i.e. places like Hawaii and Guam), a few apply within proximity to certain military bases, and one applies to... Arizona, New Mexico, Florida, half of California, the bottom piece of Nevada, and the western bit of Texas. Really.
So a universal table doesn't really work, but if you read through the actual requirements and pick out the ones that apply to you at your home QTH, then you'll end up with something nice and simple with a number per band.
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$\begingroup$ And don't forget the Canadian border proximity restrictions for 440MHz, and the National Radio Quiet Zone that includes a chunk of WV and VA (and the teeniest little parcel from MD). $\endgroup$– webmarcCommented Aug 19, 2020 at 19:48