Re: VLF: DK7FC's 11th VLF kite experiment

[Roger Lapthorn <rogerlapthorn@gmail.com>]

Good copy here of Stefan on 8.970kHz earlier, but for some reason SL has frozen so I have lost the last couple of hours as the display failed to scroll and update. This is SO annoying as with 424uHz setting it takes ages to start it again. 

Attached is the 424uHz capture which shows a bit of the continuous carrier transmission before SL stopped moving (why does it do this?).

Well done Eddie and others on more successful reception.

73s
Roger G3XBM

2011/6/16 Stefan Schäfer <schaefer@iup.uni-heidelberg.de>

Dear VLF group,

Since more than 4 months the wind and rain situation looks promising for the weekend on my /p QTH in JN49IS36VH. So i plan to do my 11th VLF kite experiment this weekend, either on Sat 18th or Sun 19th June 2011, will be announced on friday. I already announced it at the German air traffic control and just got a phone call were the permission was granted.

The plan is to come on air at about 6 UTC.

The antenna will be the 300m vertical kite antenna. I'll plan to serve the bands 33km and 46km, i.e. 8970 Hz and 6470 Hz. Since i made a new tap on the TX coil i can now resonate the 300m antenna on 6470 Hz too. This should give a about 4 dB stronger signal on 46km.

Since the gap of low QRN is much smaller now, the experiment will not take many hours, maybe just 4 or 5.

Maybe i can get the 4 kVA generator and will produce a 6 dB stronger signal but this is not clear so far. Otherwise i am limited to 550 W TX power. I will limit my antenna current to 2 A in order to prevent a HV breakdown on the coil and due to thermal losses. At 2 A antenna current i should have up to 250 mW ERP!

The program is to start a longer dash, about 40 minutes, GPS locked on 8970.00000 Hz, then a message in DFCW-600. Depending on the feedback of receiving stations i will try to send DFCW-60 or DFCW-10 or DFCW-3 and CW.
Then i'll move to 6470 Hz, transmitting a 40 minutes dash and a "K" in DFCW-600 or so.

As usual the signals will be visible on my grabber in 40 km distance:
http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber.html for 8970 Hz and
http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html for 6470 Hz (spectrogram still not available)

but surely visible on many other grabbers too ( see https://sites.google.com/site/sub9khz/vlf-grabbers for a list of available Dreamer Band grabbers).

Some new VLF receivers appeared since my last experiment. Two of them are:
http://qsl.net/4x1rf/yo/vlfgrabber.htm  (1435 km)
http://www.ok2bvg.cz/vlfgrabber/    (598 km)
Leaving a trace on these and all other new and old VLF stations is the goal! Despite high QRN and the longest days in the year (here in EU) i am optimistic.

Maybe Markus/DF6NM or Marco/DD7PC or someone else in DL wants to be available on the phone for QSP to the reflector?

Looking forward to the weekend and hope all works well and we'll have much activity.

Best 73, Stefan/DK7FC

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