Note that there are parameters on the Setup Form that will allow you to tweak the waterfall thresholds. This should allow you to find optimum settings with the preamp on or off.
Eric On Fri, Jun 26, 2009 at 2:31 PM, Tim Ellison <[email protected]> wrote: > The waterfall colors equate to the signal. > > When you engage the PREAMP, you notice that the noise floor on the > panadapter drops to a lower dB value, because the preamp is increasing the > signal to noise ratio. Remember that when you engage the preamp, you have > not changed the signal level at the antenna terminal, it stays constant. You > have, however; improved the signal to noise ratio with the preamp and > therefore the noise will go down in reference to a fixed signal level, which > in effect raises the S/N ratio. The previous statement holds true in all > cases except one. That is if the radio is antenna noise limited. > > In the above mentioned exception, atmospheric noise is a real signal just > as the desired information carrying signal is. The only way to improve the > S/N ratio in this case is by narrowing the bandwidth, match the filtering to > the characteristics of the desired signal or adjusting the AGC-T gain to > provide maximum S/N ratio. > > Since the noise has decreased with the preamp on, the intensity of the > waterfall also decreases appropriately or gets less intense. > > > -Tim > > -----Original Message----- > From: [email protected] [mailto: > [email protected]] On Behalf Of Mark Lunday > Sent: Friday, June 26, 2009 2:54 PM > To: 'FlexRadio List' > Subject: [Flexradio] Question about SDR 1.8, waterfall, and RX PRE/ATTN > settings > > I am listening on 6, and I want to look at "Panafall" which helps me > separate beacons/stations from carriers. When I turn the RX setting to PRE, > the waterfall view gets LESS intense. When I set the RX setting to ATTN, > the setting on the waterfall section gets brighter. Seems > counter-intuitive. The audio certainly behaves accordingly. As I can really > hear the 6 meter signals quite well with the RX set to PRE. > > > > Thoughts? > > > > > > Mark Lunday > > WD4ELG > > <mailto:[email protected]> [email protected] > > <http://wd4elg.net> http://wd4elg.net > > > > _______________________________________________ > 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/ > > _______________________________________________ > 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/ > _______________________________________________ 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/
