[time-nuts] Re: Rebroadcasting time signals [WAS: La Crosse Clocks - ]

[Alex Pummer]

it is relative problem-less to rebroadcast withe orthogonal polarization 
relative to the original vertical polarized signal and using a loop, not 
higher than one meter above ground -- magnetic coupling only...'Â  -- 
around your house, -- don't forget to  change the polarization of the 
antenna the ferrite- road which receiving the rebroadcasted signal -- 
driving with one simple amplifier like LM386, gain not much than 10B.
A few meter outside of the loop will be nothing  to receive, no 
interference, because 60kHz 's wave length is 5km and it is much larger 
that any loop which you could put around you  house. The receiving 
antenna should be set up that way, that it does not have coupling -- 
magnetic -- to the transmit antenna, high up in the attic above the 
center of the loop.
73
KJ6UHN
Alex

On 12/26/2020 10:45 PM, Charles Steinmetz wrote:
> 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
>
>
>
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