4 ms·

100W. Holy cow.

by klodolph 7y ago

100W. Holy cow.

turdnagel 7y ago
I have lightbulbs that can do 200W!
_wldu 7y ago
I got from the USA (east coast) to Tasmania on less than 10 watts once, but not on 70cm.
- jacquesm 7y ago
  CW?
  - _wldu 7y ago
    JT9
- lightlyused 7y ago
  I've done US east coast to Australia and New Zealand on 160m, with 5 watts and a vertical. Well, the vertical was 90' of tower and had 40,000 feet of wire underneath it and was feed with 1 5/8" hardline, but still.
  - lightlyused 7y ago
    BTW, wasn't my station, but a friends I help with.
- heypete 7y ago
  I got from central Switzerland to Japan on about 10W on 20m once using JT65 or JT9 (I can't remember which). The antenna was a random length of wire tied a rock and tossed out of my fourth-story apartment window into a field below.
CalChris 7y ago
GPS satellites broadcasting L1 signals are transmitting 25 bit/s at 25.6W and they're only about 12551 miles away and moving at 8700 mph.
- jacquesm 7y ago
  But they are line of sight. That's what makes this so special. Stars are many lightyears away, and radiate insane amounts of power the vast majority of which is lost. By the time it reaches here you may need a very long exposure to be able to see them at all. But it is line of sight. These waves were of the line-of-sight variety and somehow they were bent around the planet enough to register. That's a very hard to achieve thing.
- NovemberWhiskey 7y ago
  Voyager 1 is still in contact using a nominal 23W, despite being over 13 billion miles away and heading further out at over 10 miles per second.
  - varenc 7y ago
    Since it launched in 1979, have software updates improved the error correcting codes in Voyager's radio communications?
    - CalChris 7y ago
      That was done in 1989 with an update to Reed Solomon Viterbi – Version 2. https://sourceforge.isae.fr/projects/simplified-communications-schemes-of-voyager-i-probe/wiki/History_and_some_definitions_that_you_need_to_know https://sourceforge.isae.fr/projects/simplified-communicatio...
blendo 7y ago
At a wavelength of 70 centimeters (432 MHz). All via the magic of extremely effective error correcting codes (and fairly rare atmospheric conditions). Related, I'm amazed that my little $70 WSPR transmitter can push a 20m/14MHz signal from San Francisco to Georgia using only 0.2W, transmitting on a pretty lousy backyard dipole only 10 feet off the ground. True, it's only a beacon ("call sign Kxxxxx transmitting from SF at 200mW"), but still... WSPR being another Joe Taylor invention https://en.wikipedia.org/wiki/WSPR_(amateur_radio_software) https://en.wikipedia.org/wiki/WSPR_(amateur_radio_software)

100W. Holy cow.

turdnagel 7y ago

I have lightbulbs that can do 200W!

_wldu 7y ago

I got from the USA (east coast) to Tasmania on less than 10 watts once, but not on 70cm.

jacquesm 7y ago
CW?
- _wldu 7y ago
  JT9
lightlyused 7y ago
I've done US east coast to Australia and New Zealand on 160m, with 5 watts and a vertical. Well, the vertical was 90' of tower and had 40,000 feet of wire underneath it and was feed with 1 5/8" hardline, but still.
- lightlyused 7y ago
  BTW, wasn't my station, but a friends I help with.
heypete 7y ago
I got from central Switzerland to Japan on about 10W on 20m once using JT65 or JT9 (I can't remember which). The antenna was a random length of wire tied a rock and tossed out of my fourth-story apartment window into a field below.

CalChris 7y ago

GPS satellites broadcasting L1 signals are transmitting 25 bit/s at 25.6W and they're only about 12551 miles away and moving at 8700 mph.

jacquesm 7y ago
But they are line of sight. That's what makes this so special. Stars are many lightyears away, and radiate insane amounts of power the vast majority of which is lost. By the time it reaches here you may need a very long exposure to be able to see them at all. But it is line of sight. These waves were of the line-of-sight variety and somehow they were bent around the planet enough to register. That's a very hard to achieve thing.
NovemberWhiskey 7y ago
Voyager 1 is still in contact using a nominal 23W, despite being over 13 billion miles away and heading further out at over 10 miles per second.
- varenc 7y ago
  Since it launched in 1979, have software updates improved the error correcting codes in Voyager's radio communications?
  - CalChris 7y ago
    That was done in 1989 with an update to Reed Solomon Viterbi – Version 2. https://sourceforge.isae.fr/projects/simplified-communications-schemes-of-voyager-i-probe/wiki/History_and_some_definitions_that_you_need_to_know https://sourceforge.isae.fr/projects/simplified-communicatio...

blendo 7y ago

At a wavelength of 70 centimeters (432 MHz). All via the magic of extremely effective error correcting codes (and fairly rare atmospheric conditions). Related, I'm amazed that my little $70 WSPR transmitter can push a 20m/14MHz signal from San Francisco to Georgia using only 0.2W, transmitting on a pretty lousy backyard dipole only 10 feet off the ground. True, it's only a beacon ("call sign Kxxxxx transmitting from SF at 200mW"), but still... WSPR being another Joe Taylor invention https://en.wikipedia.org/wiki/WSPR_(amateur_radio_software) https://en.wikipedia.org/wiki/WSPR_(amateur_radio_software)