On 12/09/2014 12:06 AM, David Rowe wrote: > Hello Gullik, > > I agree and have been thinking along similar lines. Some sort of > station monitor to check that you are not over-driving your tx signal. > > If some one wants to try to modify FreeDV for IQ audio I am happy to > advise, the audio drivers support stereo and we already use IQ signals > internally. > > One issue is that many sound cards only have mono input. The radios are > very simple but stereo sound cards not common (e.g. my laptop or phone). Any desktop card will probably have a line input, (blue) jack.
As for priorities: I/Q *output* so we do not create unnesecary QRM. Unless there is traffic on *other* sideband, DSB RX is ok ( only 3 dB worse due to noise), so input is less important, mono OK. For a *check* RX you do not need any antenna :-) SM6FBD > A couple of other brainstorms: > > + Develop a FreeDV mode that works fine with DSB up and down converters. > For example half the energy in one sideband, half in the other, but > running at half the symbol rate so the total BW is about the same as a > SSB signal. This would make the hardware really simple. When we "own > the stack" we can play in novel ways. > > + The SM1001 (or whatever we call it) will have a SDR radio built in. A > HF (or VHF) tx/rx exciter (i.e. sans filters and PA) is a modest amount > of extra effort and cost. This could be used with a PC (via USB) or > stand alone. > > Cheers, > > David > > On 09/12/14 08:03, Gullik Webjörn wrote: >> I am experimenting with a fdmdv generator and receiver for testing purposes. >> This is just a NE602 osc / mixer. >> >> For testing, a DSB modulator or demodulator serves perfect, and you can >> generate and detect your own station. Using a simple generator / detector >> creates the possibility to "see" your own signal on the waterfall. >> >> This experiment could easily be expanded to a SSB generator / detector / >> QRP rig, >> if it was possible to configure freedv to: >> >> Optionally transmit both I and Q on L and R audio signals. >> >> Optionally receive both I and Q on L and R line input. >> >> SM6FBD / Gullik >> >> ------------------------------------------------------------------------------ >> Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server >> from Actuate! Instantly Supercharge Your Business Reports and Dashboards >> with Interactivity, Sharing, Native Excel Exports, App Integration & more >> Get technology previously reserved for billion-dollar corporations, FREE >> http://pubads.g.doubleclick.net/gampad/clk?id=164703151&iu=/4140/ostg.clktrk >> _______________________________________________ >> Freetel-codec2 mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >> > ------------------------------------------------------------------------------ > Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server > from Actuate! Instantly Supercharge Your Business Reports and Dashboards > with Interactivity, Sharing, Native Excel Exports, App Integration & more > Get technology previously reserved for billion-dollar corporations, FREE > http://pubads.g.doubleclick.net/gampad/clk?id=164703151&iu=/4140/ostg.clktrk > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=164703151&iu=/4140/ostg.clktrk _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
