On 05/07/17 22:46, David Tiller wrote: > If you knew you had to send an ID with a packet, could you not reduce the > amplitude of the whole data packet by a db or so and re-allocate that power > to the CW ID? It certainly doesn't have to be loud, much like repeaters do > id-under-voice. That way the FT8 signal taken by itself would still be > constant envelope, and the CW id could be sent way down at FDial+100Hz. If > the OOK nature of CW is the issue, you could always treat it as FSK using 1 > Hz and 100Hz. The 1Hz component would get chopped out in the radio, leaving > the ID and FT8 signal.
I can see a number of potential pitfalls. First, because there are two tones present, there will be intermodulation products between them. These will undoubtedly raise the noise floor. With an average rig we could expect to see 3rd order IPs in the ballpark of 20-25 dB below each tone. That's quite serious. Second, because the sum of the two tones is not constant envelope, it's going to really confuse the issue with levels and power. Third, if you reduce the data by 1 dB and reallocate the power then the CW ID will be 19 dB down on the FT8 alone. Is that enough? Fourth, if everyone is IDing on Fdial+100Hz, how does anyone listening know which CW ID belongs with which FT8 packet? 73, Richard G4DYA ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
