3 ms·
The indicated FT8 signal to noise ratio is very misleading. The calculation is based on a noise bandwidth of 2500 Hz, yet the FT8 signal is only 50 Hz. The actu
by drmpeg 7y ago
The indicated FT8 signal to noise ratio is very misleading. The calculation is based on a noise bandwidth of 2500 Hz, yet the FT8 signal is only 50 Hz. The actual minimum signal to noise ratio of FT8 is around 1 dB in 50 Hz (-156 dBm in a gaussian channel with a perfect 0 dB noise figure receiver), which is consistent with a 1/2 rate LDPC code like the one FT8 uses.
- madengr 7y agoThank you! Was just about to point that out too. Drives me nuts when the standard SSB bandwidth is used. People transmitting 100W on HF with WJSTX modes is another pet peeve.
- paulirwin 7y ago100W FT8 bothers you? There are people pumping 1500W on FT8. I would get the sentiment on WSPR though. I run 100W, and I'm rarely picked up above -7dB. Some of us have to given our QTH, antenna, and where we're trying to reach. Not all of us are in it for QRP. Perhaps they should designate a part of the FT8 bandwidth for QRP? 73
- SamPatt 7y agoI don't get the hate for 100 Watts on FT8 either. Use the power you need to make the contact. Keep an eye on the waterfall to make sure you aren't doubling. If you're getting a +5 SNR report then obviously dial it way back but when I do DX at 100 Watts it's usually -10 or less. Of course that's for QSOs usually well over 3k miles.