The xtal causes close to zero carrier for a period of time on each phase shift. Regards Paul WB8TSL
On Thu, Sep 27, 2012 at 10:07 AM, J. Forster <j...@quikus.com> wrote: > The AM just makes the situation in low S/N areas worse. The BPSK wipes out > the possibility of any very narrow band prefiltering, because of filter > time response. > > I suspect, although have not tested, that active antennas with either > mechanical or crystal filters in their preamps will be rendered useless. > > -John > > =============== > > > > The AM characteristics have not changed. That means that there is at > least > > 10% carrier present at all times. > > The transmission format seems pretty well documented. The remaining > > mysteries are in data formatting. > > Regards, > > Dale NV8U > > > > > > -----Original Message----- > > From: Peter Monta > > Sent: Thursday, September 27, 2012 1:52 AM > > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] WWVB Response > > > > Hi John, > > > > Thank you for clarifying the openness of the transmission format. > > Could I ask whether there is any scenario under which aspects of the > > signal transmission design might be patented? If companies or > > individuals wish to patent aspects of receiver design, that's fine, > > but I'd be uncomfortable with a patent-encumbered transmission format. > > > >> ... It is an unfortunate consequence of improving the reception > >> capability of our broadcast that this segment of our loyal user base are > >> so > >> adversely affected. The decision to proceed was not taken lightly, but > >> in > >> the end it was decided that the improvement in reception capability > >> (especially along the JJY interference prone East Coast) outweighed the > >> loss > >> of use of existing PLL devices. > > > > I suppose it's a matter of balancing the value of the PLL receivers > > and the loss of BPSK signal power to the residual carrier. If the > > power loss is small, though, say 0.5 dB or below, then given the large > > process gains of the advanced receivers, it might be worth > > considering. I don't imagine that the mere presence of residual > > carrier has any effect on the advanced receivers (since it is similar > > to interference from MSF and JJY, as you say), but please correct me > > if I'm wrong. > > > > Cheers, > > Peter > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.