60 kHz (2022)

Post by cycomanic » Sat, Jun 01, 2024, 8:51 AM UTC

YZF wrote: post #87

nico wrote: post #80

Earlier quoted context omitted.

I guess my usual experience is that AM transmissions sound pretty horrible, especially compared to FM So, my question is more like, can we just upgrade the equipment and keep the channels? And can AM be used more like for signal/indexing rather than full data dump? (eg. instead of transmitting the whole song, transmitting just an id of the song)

The limit is Shannon's law which depends on bandwidth and signal to noise. A more advanced modulation technique can get more "information" through up to that limit. A song for this matter can just be considered information as well. So the answer is almost certainly yes, one can get more out of existing channels by upgrading the equipment assuming the current equipment doesn't approach the theoretical limit which is a…

Post by servus45678981 » Sat, Jun 01, 2024, 8:58 AM UTC

nocoiner wrote: post #57

systemvoltage wrote: post #54

Slightly tangent: being substantively patriotic is cool. It should be cool. America has done some incredible things like this and I’m sure it’s not just Americans that find it cool.

Well said. I couldn’t agree more. I think there are a lot of countries that have done some really remarkable things. I’m American, and I’m generally very proud of my country. If I were, say, French, Swedish or Japanese, I’d feel the same way. Obviously none of those countries - or any country - is perfect, and all have some distinctly dark chapters in their past, but there’s something inspiring about a society organi…

Post by kqbx » Sat, Jun 01, 2024, 9:29 AM UTC

stkdump wrote: post #74

morpheuskafka wrote: post #55

Earlier quoted context omitted.

> a more popular idea seem to be to piggy back onto GNSS signals Don’t all GNSS systems provide a highly accurate time signal (maybe needed for computing the distance to satellite)? I know GPS does at least.

As mentioned somewhere else, these time signals also carry information about DST and adapt for leap seconds, both of which GPS doesn't do as far as I know. I remember that earlier versions of Android always set the phone clock to GPS which was then off by a number of seconds.

Post by nabla9 » Sat, Jun 01, 2024, 10:07 AM UTC

tanepiper wrote: post #97

> I’m not particularly patriotic, but this kind of thing feels particularly American. Maybe that tinge of patriotism is why Americans don't even bother to see if something isn't an American invention - https://en.wikipedia.org/wiki/Time_from_NPL_(MSF) - they'll just claim it anyways since they barely read outside their borders. Radio 4 would also like a word: https://en.wikipedia.org/wiki/Greenwich_Time_Signal

Post by quintushoratius » Sat, Jun 01, 2024, 10:39 AM UTC

lxgr wrote: post #63

V99 wrote: post #44

Earlier quoted context omitted.

They usually have an offset and a DST option. So in Arizona you'd choose -7/Off, and never touch it again. In Colorado you'll have to toggle DST twice a year manually, because it doesn't know the rules for when it starts/ends.

Oh, is there no “DST in effect” flag in the signal? As I understand it, the US switches at the same day across the country (for the states that do have it), so that should theoretically be possible.