NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Listening to WWV from 60N 30E
From: Paul Hirose
Date: 2018 Sep 28, 14:50 -0700
From: Paul Hirose
Date: 2018 Sep 28, 14:50 -0700
On 2018-09-27 13:45, Tony Oz wrote: > As a SW-listener I can confirm that WWV is not easy to listen to - from my QTH (of 60°N 30°E). Their time-ticks are quite discernible at times but their voice messages are far too weak. My guess - they use the worst modulation available: AM. If they had a properly compressed voice over SSB - the usable range of their transmissions would be much wider. Even DSB with an unmodulated carrier (for compatibility with valve/tube-radios!) is more preferable. > My rig is Sony ICF-SW100 and a 5-meter long wire "antenna". > When there is a propagation - I do hear them at 10MHz and 15 MHz, at 5MHz they are squarely under the BPM's loud transmission. There's more to WWV than time ticks and voice. It is also a frequency standard. For example, the Winradio Excalibur receiver has a feature which displays its frequency error (parts per million) with respect to the carrier. If desired, the radio will calibrate itself to the carrier. That won't work with a single sideband signal since there's no carrier. Also, audio frequencies in a demodulated SSB signal are affected by any error in the receiver tuning. Each Hz of error shifts the whole audio spectrum up or down the same amount. Thus the 440 Hz tone from a single sideband WWV would not be reliable for testing a musical instrument tuner. Canadian station CHU transmits upper sideband plus carrier. It avoids interference by operating far from the standard time frequencies. https://www.nrc-cnrc.gc.ca/eng/services/time/short_wave.html
