30th November 2010 - 9kHz Grabber. Today I have set up a 9kHz grabber for enthusiasts and experimenters to periodically view what is being received at my QTH, locator IO83qo, North West England. The Spectrum Laboratory captures can be viewed here and using the link displayed on the "Links" page. The uploads are usually at 30 minute periods. Other details are shown in the information box.
4th December 2010 - 8.970kHz Signal Received. For the first time I received a signal on 8.970kHz which was not generated locally by myself. It was transmitted by Stefan DK7FC from near Heidelberg in Germany, the distance is 889 Kms (552 miles). The receive system used was a 1100mm square, 46 turn loop & M0BMU pre-amp fed into a sound card on my personal computer, the display software in use was Spectrum Laboratory which is frequency locked to a VLF MSK transmitter. The details of the loop and pre-amp are described earlier in these pages. The transmission includes an identification message "CU" using DFCW mode, this was partially obscured by very strong interference (QRN).
Stefan's signal at 8.970kHz and table of receptions
Note : The acronym DFCW in full is Dual Frequency Carrier Wave, this employs the morse code method of communicating but instead of dots and dashes (short and long elements) all the elements are of equal length. The deciding factor is that the lower element equals a dot and the upper element a dash. This type of slow morse code takes less time to transmit, therefore making the communication period much shorter.