5 ms·

1500W! Wow, that’s a lot, especially compared with the limits of lower frequencies like 1W or 5W. On the 630 metres frequencies: > 5 W EIRP maximum, except in

1500W! Wow, that’s a lot, especially compared with the limits of lower frequencies like 1W or 5W. On the 630 metres frequencies: > 5 W EIRP maximum, except in Alaska within 496 miles of Russia where the power limit is 1 W EIRP. Wonder where that weird distance came from. 496 miles ≈ 798.2km, so it’s just below what I’d expect to be chosen as a round number, whether defined in miles or kilometres.

csunbird 5y ago
It is probably 800km and they rounded the miles to 496 instead
- chrismorgan 5y ago
  800km ≈ 497.1km. You’re not likely to round that to 496.
  - rpeden 5y ago
    Lots of people learned in school (in my part of Canada, at least) that 1km = 0.62 miles. If you use that value, you get 800km = 496 miles. Seems like that's what happened here.
    - chrismorgan 5y ago
      Hmm, so the statute is probably in metric and this particular site made this error in conversion? Still feels a weird error to make, I’d expect to (a) use metric, (b) use a more correct conversion, or (c) round up to 500. From the metric perspective, most people go with 1 mile = 1.6km, which is a bit less accurate (about −0.58%, rather than about +0.22%), but definitely easier to work with.
      - rpeden 5y ago
        It's in FCC §97.313 (l) and you're right, it's metric: https://www.law.cornell.edu/cfr/text/47/97.313 https://www.law.cornell.edu/cfr/text/47/97.313
      - rpeden 5y ago
        Anther follow-up in case someone stumbles upon this in the future and wants more information. The 800km limit applies to quite a few countries. Many of them (but not all) were members of Soviet Union. You can find a list here: https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10759.html https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10759.html (search for "800 km".) It looks like these come from the ITU table of frequency allocations so there's likely some history behind the 800km limit. I haven't found any great information yet, but will add it if I do.

csunbird 5y ago

It is probably 800km and they rounded the miles to 496 instead

chrismorgan 5y ago
800km ≈ 497.1km. You’re not likely to round that to 496.
- rpeden 5y ago
  Lots of people learned in school (in my part of Canada, at least) that 1km = 0.62 miles. If you use that value, you get 800km = 496 miles. Seems like that's what happened here.
  - chrismorgan 5y ago
    Hmm, so the statute is probably in metric and this particular site made this error in conversion? Still feels a weird error to make, I’d expect to (a) use metric, (b) use a more correct conversion, or (c) round up to 500. From the metric perspective, most people go with 1 mile = 1.6km, which is a bit less accurate (about −0.58%, rather than about +0.22%), but definitely easier to work with.
    - rpeden 5y ago
      It's in FCC §97.313 (l) and you're right, it's metric: https://www.law.cornell.edu/cfr/text/47/97.313 https://www.law.cornell.edu/cfr/text/47/97.313
    - rpeden 5y ago
      Anther follow-up in case someone stumbles upon this in the future and wants more information. The 800km limit applies to quite a few countries. Many of them (but not all) were members of Soviet Union. You can find a list here: https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10759.html https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10759.html (search for "800 km".) It looks like these come from the ITU table of frequency allocations so there's likely some history behind the 800km limit. I haven't found any great information yet, but will add it if I do.