Time Signals

On long- and shortwave there still are a number of time signals. Not as many as there  used to be, since the smaller stations have mostly signed off. On longwave here in Taiwan I can hear time signals from JJY (60 kHz 24/7, 40 kHz at night) and BPC (68.5 kHz 24/7). There is also a station on 77.5 kHz, 24 hours a day, weaker than JJY on 60 kHz but stronger than JJY on 40 kHz. The only TS listed on 77.5 kHz is DCF77 in Germany, but it seems improbable that I can receive that 24 hours a day.

On January 13th at 0045 UTC I made a recording to compare what I hear on 77.5 kHz with the DCF77 signal which I received via the VLF webSDR at the Technical University Eindhoven. For 77.5 kHz I used an IC-7200 with Jackson Harbor Press LF converter and a 12 meter vertical antenna. I deliberately tuned 50 Hz below the frequency to create a tone difference between the two signal. Both were then fed into a Behringer UCA202 USB soundcard with one signal into the left and the other into the right channel. This was recorded using Audacity, then split and time shifted, as the DCF77 signal had some 300 ms latency because of the internet.

The screenshot of Audacity, clearly showing a difference between DCF77 and the signal received here in Taiwan.

Original unshifted recording. The left channel is 77.5 kHz, the right channel DCF77.

The DCF77 signal from the TUE webSDR.

The 77.5 kHz signal as received in Taiwan.

The main difference between DCF77 and the TS I receive is the various dots and dashes in the second half of the minute.

To be continued.