Hal wrote:
Transmitting on the same frequency you are receiving on seems like asking for troubles.
Difficult perhaps, but not impossible. As /tvb notes, one solution is time domain multiplexing; and, as Alex says, phase domain multiplexing is another (although the phase discrimination of 60kHz antennas this size is problematic). There are others.
How far apart would the antennas have to be? How would you calculate that distance? Or what is the right question?
I've watched discussions of this topic for several years, and have always been surprised that nobody has ever once mentioned the potential for harmful interference extending beyond one's own property. (Tom mentioned it today, including the possibility of legal implications.) This is especially true of people, like some on this list, who reportedly run a big loop around their house ("so that all their WWVB clocks can hear it"). But really, any scheme with leakage can (and likely does) create harmful interference beyond your property.
I can say positively that if anyone who has such a system lived down the block from me, I would be most unhappy about it and would be in a very foul mood by the time I figured out what was causing the interference I was receiving. (I know whereof I speak -- I spent quite a lot of effort a few years ago chasing down a leaking 10MHz reference of very dubious quality in use by a local ham nearly a kilometer from me.)
So, please, if you are going to rebroadcast a time signal to your receivers, make sure the modulator and RF generator are in well-RF-sealed enclosures and that you use good coax (or, preferably, triax) to send the signal to each receiver individually. BTW, this applies to *any* such signal, not just LF but HF and GNSS rebroadcasters as well.
Best regards, Charles _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
