Until the enhancement is coded can we use a low tech stop watch to time the rotation of the phase display and average the time over many rotations? i.e. does the phase rotation of the bin correlate closely to the rotation of the phase display?
Ted NX6C ________________________________ From: Tim Ellison <[email protected]> To: Bob McGwier <[email protected]>; Flex Edge <[email protected]> Sent: Tue, November 16, 2010 4:47:18 AM Subject: Re: [FlexEdge] FMT next time Sounds like an enhancement for the Frequency calibration routine in PowerSDR <wink>. -Tim -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Bob McGwier Sent: Tuesday, November 16, 2010 6:47 AM To: Flex Edge Subject: [FlexEdge] FMT next time 1) I want to listen to WWV with a larger FFT than we currently listen to in the the code. 2) I want to listen to contiguous blocks of these FFT results. The phase spin of the WWV carrier is DIRECTLY usable to compute the frequency offset (up to ionospheric disturbance) and should lead to mHz accuracy. Using this computed estimate of the oscillator inaccuracy in the receiver we can then apply the same process in an FMT with the calibrated receiver. If you have a carrier and apply successive FFT blocks to it, the phase rotation of the bin containing the FMT carrier gives the frequency offset from the center of the block and can be made more accurate by filtering the resulting offsets to get a more noise free version. Bob N4HY -- (Co)Author: DttSP, Quiktrak, PowerSDR, GnuRadio Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. "Be yourself, because the people who mind don't matter. And the people that matter don't mind." -Dr. Seuss Active: Facebook,Twitter,LinkedIn _______________________________________________ Flexedge mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software development and experimentalist who are using beta versions of the software. _______________________________________________ Flexedge mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software development and experimentalist who are using beta versions of the software. _______________________________________________ Flexedge mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software development and experimentalist who are using beta versions of the software.
