On Sep 15, 2010, at 10:15 AM, Alan Bloom wrote:
> If you turn on averaging in the waterfall you can see farther down into the noise. It works best on steady carriers. With CW signals you have to keep the averaging time less than a dit.
I have found that per-bin averaging of the power spectrum works rather well even with low duty cycle, keyed carriers. Take a look at the two waterfalls in the "Weak Signal Button" section that is almost at the end of this page:
http://homepage.mac.com/chen/w7ay/cocoaModem/UsersManual/mfskManual/mfskManual/dominoex.htmlThe signal that you see there is DominoEX, where each carrier is present on average for only one out of 18 chip periods. Moreover, with DominoEX, if a carrier is on for one chip, it is always off during the next chip, so there is never a "dah," as in CW, but only very short "dits."
73
Chen, W7AY
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