(no title)
cactacea | 3 months ago
Tx power: 1 W per antenna
Yeah... so free space path loss at legal frequencies for hams this thing can transmit on is ~283dB. Neat idea but consider me skeptical. Having said that I can see some interesting applications for this kind of gear, EME seems overly optimistic though.
dbcurtis|3 months ago
A few years ago I was experimenting with 900 MHz LoRa for a work project -- we had need to communicate a very small data payload from inside elevator cabs, with forgiving latency requirements. So we took a LoRa board to a hotel building 2 city blocks away from our lab and cranked the coding gain up to the max, which gave us about a 1 byte payload every second. Perfectly sufficient for our application. Astoundingly, we had great copy in our lab even when the doors of the elevator cab were closed, inside a building 2 blocks away. I can't remember the power level, 500mW I think, but I may be wrong.
mystraline|3 months ago
https://gitlab.com/crankylinuxuser/meshtastic_sdr
firesteelrain|3 months ago
Neywiny|3 months ago
drmpeg|3 months ago
63.1 dbW = 93.1 dBm (240 watts + 39.3 dB gain)
path loss at 5760 MHz = 283.2 dB (at perigee)
RX gain = 39.3 dB
93.1 - 283.2 + 39.3 = -150.8 dBm
Noise floor at 1.2 dB noise figure and 500 Hz bandwidth = -151.9 dBm
SNR = +1.1 dB (easily detectable by ear with CW).
jacquesm|3 months ago
cactacea|3 months ago