Re: [wsjt-devel] Impact of multi stream on SNR
Thnaks to Joe K1JT that directed me to the right answer https://wsjt.sourceforge.io/FT8_DXpedition_Mode.pdf page9 If you are using N Slots signals, your average transmitted power will be P0/(N Slots) and the power in each signal will be P0/(N Slots) 2. Thus, for N Slots = 1, 2, 3, 4, and 5 the average power per signal will be down from P0 by about 0, 6, 9.5, 12, and 14 dB, respectively. On Sat, Jan 7, 2023 at 2:28 PM José Nunes CT1BOH wrote: > I wonder if anyone can confirm this?! > > In FT8 if I copy a DX station TX, with only one stream, at -10dB: > >- If the station goes F/H with two streams, then the signal of each of >the two streams goes down to -13,01 dB because the energy of one stream is >split by half >- If the station goes F/H with three streams, then the signal of each >of the three streams goes down to -14.77 dB because the energy of one >stream is split by three > > Are the two sentences above correct? > > -- > José Nunes > CONTEST CT1BOH - http://www.qsl.net/ct1boh > -- José Nunes CONTEST CT1BOH - http://www.qsl.net/ct1boh ___ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
Re: [wsjt-devel] Impact of multi stream on SNR
On 1/7/2023 9:28 AM, José Nunes CT1BOH via wsjt-devel wrote: I wonder if anyone can confirm this?! In FT8 if I copy a DX station TX, with only one stream, at -10dB: * If the station goes F/H with two streams, then the signal of each of the two streams goes down to -13,01 dB because the energy of one stream is split by half * If the station goes F/H with three streams, then the signal of each of the three streams goes down to -14.77 dB because the energy of one stream is split by three Are the two sentences above correct? No, this is not correct. With two streams, each stream will be weaker than the one-stream case by 6 dB. See "Important Note for Fox Operators" on page 9 of the "FT8 DXpedition Mode User Guide": https://wsjt.sourceforge.io/FT8_DXpedition_Mode.pdf https://wsjt.sourceforge.io/FT8_DXpedition_Mode_Portuguese.pdf -- 73, Joe, K1JT ___ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
[wsjt-devel] Impact of multi stream on SNR
I wonder if anyone can confirm this?! In FT8 if I copy a DX station TX, with only one stream, at -10dB: - If the station goes F/H with two streams, then the signal of each of the two streams goes down to -13,01 dB because the energy of one stream is split by half - If the station goes F/H with three streams, then the signal of each of the three streams goes down to -14.77 dB because the energy of one stream is split by three Are the two sentences above correct? -- José Nunes CONTEST CT1BOH - http://www.qsl.net/ct1boh ___ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
