That should be I/Q modulator. Too much of a computer head, I guess... On 02/08/2015 01:37 PM, Bruce Perens wrote: > OK, I should explain a bit more about the amplifiers. 50-1000 MHz is an > amplifier with a 950 MHz band width, and we may indeed be able to make > the device work on the 1200 MHz band so it could be even more. Now, > notice how much work is put into making your HF amplifier work legally > on just 1-30 MHz. Lots of filters, etc. We need spurious emissions to be > greater than 60 dB down across much of that range to satisfy U.S. > regulations for Amateurs. We need it to be free of parasitic > oscillation. We need it to have low-pass filters for the selected bands. > > So, this is down as "the next project" and is a really non-trivial one, > and we have to make both a handheld and mobile/base version. To make the > current device is hard enough and we're not going to make it wait for > this since single-band amplifiers like the ones from Down East Microwave > are easily available. > > To give you an idea of what is involved in making the transceiver legal, > the I/O modulator is self-balancing. To do this there are two DACs which > provide a + or - offset to the I/O inputs, and there is a logarithm > detector that can be switched in instead of the 100 mW amplifier to > measure carrier or sideband suppression. There are four plug-in bandpass > filters for your selected bands, used on both receive and low-power > transmit, or they can be switched out and external filtering can be used. > > All of this is necessary to give us that greater than 60 dB down > spurious at just 100 mW. > > Thanks > > Bruce > > > > ------------------------------------------------------------------------------ > Dive into the World of Parallel Programming. The Go Parallel Website, > sponsored by Intel and developed in partnership with Slashdot Media, is your > hub for all things parallel software development, from weekly thought > leadership blogs to news, videos, case studies, tutorials and more. Take a > look and join the conversation now. http://goparallel.sourceforge.net/ > _______________________________________________ > Freetel-codec2 mailing list > Freetel-codec2@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freetel-codec2
------------------------------------------------------------------------------ Dive into the World of Parallel Programming. The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2
