On Tue, Aug 25, 2009 at 7:29 AM, Lee A Crocker<[email protected]> wrote: > PSK31 has terrible dynamic range That is why everyone looses their minds > when you run more than 20 watts
Good point but it is not quite that bad. FWIW, I typically run my Flex5000 at 1dB down from max output. That produces about 70W peak output. It has no problem with either the PSK or the MFSK modes. Linearity is very good. As to the why, yes, there is an amplitude component to PSK31 in order to limit the sideband energy (pure BPSK has sidebands decreasing out to infinity). If you overdrive your amplifier such that it clips/compresses and eliminates the amplitude component you end up with pure BPSK then you get to see all those sidebands. (We call it IMD.) But the peak-to-average ratio is about 3dB as I recall so making sure your average signal level is 3dB below the maximum output of your radio will fix that. If you are using a peak-reading wattmeter then you just need to make sure that envelope peaks are below the max output of the PA. -- 73 de Brian, WB6RQN/J79BPL _______________________________________________ FlexRadio Systems Mailing List [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ Message delivered to [email protected]
