Here is what I see after XG-1 claibration. No antenna connected. Pre amp off: ~-97 dBm, RX Signal = S5 Pre amp low: ~-107 dBm, RX Signal = ~S3.25 Pre amp med: ~-121 dBm, RX Signal = S1 Pre amp high: ~-129 dBm, RX Signal = Zero (no movement)
On 8/18/06, Martin Hirsch <[EMAIL PROTECTED]> wrote: > I think the S-Meter reading should be zero if the preamp setting is 'high' > and no antenna (or a dummy) is connected to the sdr , even if 2.7kc bandwith > is selected. If it shows S2 = ~ -115dBm =~ -8dBµV =~ 0,45µV (as in your > case, Tim) it indicates a receiver sensitivity worse than 1µV for 10dB S/N > ,thats not really good. > > Martin > > ----- Original Message ----- > From: "Tim Ellison" <[EMAIL PROTECTED]> > To: "Martin Hirsch" <[EMAIL PROTECTED]> > Sent: Friday, August 18, 2006 5:12 PM > Subject: RE: [Flexradio] Signal to Noise > > > As noted below "Using Panadapter with averaging turned on." I am > reading from the Panadapter. > > > -Tim > --- > Integrated Technical Services > > "Lately it occurs to me, what a long strange trip it's been." > -Robert Hunter > > -----Original Message----- > From: Martin Hirsch [mailto:[EMAIL PROTECTED] > Sent: Friday, August 18, 2006 11:07 AM > To: Tim Ellison > Subject: Re: [Flexradio] Signal to Noise > > Hello Tim, > > your dBm readings do not match your S-meter readings and they do not > match the expected attenuation-steps, where did you read them ? > > Martin > > ----- Original Message ----- > From: "Tim Ellison" <[EMAIL PROTECTED]> > To: "Scott Gordon" <[EMAIL PROTECTED]>; <FlexRadio@flex-radio.biz> > Sent: Friday, August 18, 2006 6:17 AM > Subject: Re: [Flexradio] Signal to Noise > > > > Scott, > > > > As an experiment, I just tried your settings after calibrating with my > > XG-1. > > Selected filter on LSB 2.7 KHz @ 7.200 MHz into a dummy load. > > Firebox (upgraded with bug riddled firmware) @ 96 KHz sampling rate > > Using Panadapter with averaging turned on. > > > > I get: > > > > Pre amp off: -112 dBm, RX Signal = S6 > > Pre amp low: -120 dBm, RX Signal = almost S5 > > Pre amp med: -122 dBm, RX Signal = S4 > > Pre amp high: -132 dBm, RX Signal = S2 > > > > If I leave the preamp on high and select CWL with a 50 Hz filter: > > Pre amp high: -136 dBm, RX Signal = S meter barely moves > > > > > > -Tim > > --- > > Integrated Technical Services > > > > "Lately it occurs to me, what a long strange trip it's been." > > -Robert Hunter > > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of Scott Gordon > > Sent: Thursday, August 17, 2006 9:40 AM > > To: FlexRadio@flex-radio.biz > > Subject: Re: [Flexradio] Signal to Noise > > > > Martin, > > > > 1.) My pre-amp is set on low > > 2.) Level Meter reads S3 with -103 dbm (low) S2 -114 dbm (med) S1 > -121 > > dbm (High) > > 3.) Selected filter on LSB 2.7K 7.200 hz > > 4.) Calibrated with XG1 > > > > This is into a dummy load or with SDR unhooked. > > > > Thanks > > Scott > > > > -----Original Message----- > > From: Martin Hirsch [mailto:[EMAIL PROTECTED] > > Sent: Thursday, August 17, 2006 8:05 AM > > To: flexRadio@flex-radio.biz; Scott Gordon > > Subject: Re: [Flexradio] Signal to Noise > > > > > > Hello Scott, > > > > the indicated level depends on: > > 1.) preamp setting > > 2.) whether you are reading the Level-Meter or the > Panadapter-line-level > > 3.) the selected filter > > and of corse if you did the calibration properly. > > Slight diferences may occure on different bands. > > > > My readings with antenna disconnected on 14.250kcs and 500Hz cw are: > > > > > > on RX-Meter: on > > Panadapter: > > > > preamp high: ~ -142dBm ~ > > -153dBm > > med ~ -133dBm > ~ > > - > > 143dBm > > low ~ - 124dBm > > ~ -135dBm > > off ~ - 114dBm > > ~ -125dBm > > > > As you can see I never reach the -104dBm Level. I get 104dBm Meter- > > reading > > when the preamp is off and the filter is set > 3.3kHz. > > Hope I could help with this. > > > > 73's Martin > > > > > > > > ----- Original Message ----- > > From: "Scott Gordon" <[EMAIL PROTECTED]> > > To: <flexradio@flex-radio.biz> > > Sent: Thursday, August 17, 2006 1:16 PM > > Subject: [Flexradio] Signal to Noise > > > > > >>I am seeing on all bands into a dummy load or without a antenna > connect > > > >>to the flex a S3 to S4 noise level or -104dbm. Seems like it should > be > > > >>closer to zero unless getting some noise from somewhere else. Can > >>someone try theres and see what your reads. > >> > >> Thanks > >> Scott > >> http://www.kq8rp.us > >> -------------- next part -------------- > >> An HTML attachment was scrubbed... > >> URL: > >> > > > /pipermail/flexradio_flex-radio.biz/attachments/20060817/3c519aaa/attach > > ment.html > >> _______________________________________________ > >> FlexRadio mailing list > >> FlexRadio@flex-radio.biz > >> http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > >> Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > >> FlexRadio Homepage: http://www.flex-radio.com > > > > > > _______________________________________________ > > FlexRadio mailing list > > FlexRadio@flex-radio.biz > > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > > Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > > FlexRadio Homepage: http://www.flex-radio.com > > > > _______________________________________________ > > FlexRadio mailing list > > FlexRadio@flex-radio.biz > > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > > Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > > FlexRadio Homepage: http://www.flex-radio.com > > > _______________________________________________ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com > -- "There is nothing more uncommon than common sense." -- Frank Lloyd Wright _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
