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.
