VLF test Saturday June 18th (DK7FC/P)

Tomorrow morning Stefan DK7FC/P will be testing for the first time in many months using his kite supported VLF antenna. He will be transmitting from mid Germany on 8.9700000kHz (precisely GPS locked) from around 0600z Saturday. His ERP will be in the 50-250mW region.

If you have Spectrum Laboratory (free software) and a suitable E-field probe or loop antenna then this is a great chance to see if you can detect his signals. The last time he tested he was quite a good signal in the UK and was received by several suitably equipped stations.

It is unlikely his signal will be audible, but he should be a clear trace on the SL screen with a suitably narrow bandwidth setting (4.52mHz or less). Frequency accuracy is paramount and you will need a Spectum Lab config file that "locks" onto GBZ or similar to ensure you know precisely where to look. Initial tests will be with a long carrier followed by characters in very slow DFCW or QRSS.

You do NOT need a VLF communications receiver: just a loop or E-field probe and a small audio preamp feeding the sound card of a PC. This is amateur radio "at the edge" in the same way that optical comms is .....but at the other end of the spectrum. Great fun and a nice challenge.

I shall be looking and streaming the received signals to my VLF grabber visible at https://sites.google.com/site/sub9khz/vlf-grabbers/xbm-grabber . It is also possible that G3ZJO will have his (better) VLF grabber on too at http://g3zjo.bplaced.net/ . The RSGB LF-reflector will carry updates in the event of the kite blowing away, going QRT for storms etc..