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I'm looking for any timecode station (like WWV/B, CHU, etc.) with an SNR > 0 dB that I should be able to receive in Boston Mass.

WWVB at 60 kHz has a phase modulation that one can apparently receive on the east coast, but the signal is borderline to begin with and I'd like something I can see or hear without code gain.

CHU in Ottawa, Canada transmits on 3 frequencies, including 3.33 MHz at 3kW but I don't know if I should be able to receive it. I haven't managed to yet.

Of course I can receive GPS but that's not the point.

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  • $\begingroup$ maybe if you explain what your application for that signal is, you can get even better answers (though the two you got are already pretty good!) $\endgroup$ – Marcus Müller Mar 8 '18 at 9:16
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    $\begingroup$ You may just need to lengthen and/or reorient your antenna. Wire antennas have nulls along their length, so it would ideally be pointed perpendicular to the shortest path to the transmitter you want to receive. Experiment, and you may do better. Also, an outdoor antenna tends to do better than an indoor one. $\endgroup$ – Jim MacKenzie VE5EV Mar 8 '18 at 19:20
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WWVB propagation does vary in amplitude. And its BPSK phase modulation makes it a bit tricky to lock to. But if you narrow the bandwidth enough, signal is most always above the noise.
Here's an example plot of WWVB amplitude in a fringe area similar to Boston...left half is night-time while right half is day-time. Each sample is exactly one second long. Bandwidth of this receiver is about one hertz.
You see three different amplitude samples, because the integrated amplitude each second can take on three different digital codes (low, high, or sync).
The vertical amplitude scale is arbitrary, proportional to volts, not watts. Antenna was a 0.7 m loop at ground level resonated to 60 kHz. A ferrite rod antenna produces similar results.wwvb carrier amplitude

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  • $\begingroup$ I was just able to get CHU at 3.33 MHz after reducing my IF bandwidth drastically. I'm using a cheap SDR and an upconverter. My antenna is a length of wire. (I chose this answer for the bandwidth comment) $\endgroup$ – Martin Klingensmith Mar 8 '18 at 12:26
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You should be able to pick up WWVB at 60 kHz, or WWV at 2.5, 5, 10, 15, and 20 MHz. Propagation should allow you to routinely receive at 60 kHz, 2.5 MHz, and 5 MHz most nights unless the ionosphere has been disturbed by an event such as a solar flare. That would likely be your most reliable propagation.

During the day time you should be able to receive 15 MHz on most days. 10 MHz should come through best in the mornings and evenings. 20 MHz should come through during the day time when the sunspot number is reasonably high, or when propagation is otherwise favorable.

This assumes that you have a reasonably effective antenna. A typical inexpensive WWVB-synchronized clock uses a fine coil of wire around a ferrite rod.

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  • $\begingroup$ I think I need to improve my frequency reference. I see something at 2.5 MHz for example, but I'm not sure I trust that it is what I think it is. The shortwave AM signal like CHU is undeniable. I will try decoding WWVB when I have time to experiment more. Thanks for the information. $\endgroup$ – Martin Klingensmith Mar 8 '18 at 12:57
  • $\begingroup$ @MartinKlingensmith if you're getting good reception of WWV (not WWVB) you should be able to hear voice near the end of each minute, in addition to the tones and second pips. $\endgroup$ – hobbs - KC2G Mar 9 '18 at 3:45
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Apart from the American time signal stations on shortwave. There is also CHU the Canadian time signal from Ottawa on 3.330 MHz, 7.850 MHz, and 14.670 MHz using USB mode.

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