Re: VLF: Back on 5.17 kHz / 58 km...

[Paul Nicholson <vlf0403@abelian.org>]

Yes I keep thinking about kites.  It sounds like a lot
of fun.

I've had a powersled 36TT on order from Kiteworld (UK)
since last May, for some reason they don't seem to be
able to send one.   I think that's like the one you
used in 2010 for your first series of VLF experiments.
I'll have to order one direct from Germany.

Meanwhile I have a powersled 24 which is quite big
enough.  It flies very steady.   In the UK we are
limited to only 60m height above ground. I am
surrounded by hills of over 100m so I might anchor
the kite at the top of the hill behind the house - if
the wind is right it will be 60m above the anchor and
170m above the house!

>  i tested (again) my new coil for 8270 Hz.

It is a long time since I saw a signal on the 8270Hz
band.   There was a carrier for 2 hours at 8270.002 on
1st Jan 10:20 to 12:20 approx.  Markus?  The last strong
signal was 17th Dec from DJ8WX.

I've been experimenting with changes to the sferic
blanking.  Gained about 1dB at 5170.  Your recent 24 char
daily repeats:

        Was      Now
 10th  -5.8 dB  -4.5 dB (-62.6 dB in 2500Hz)
 11th  -5.3 dB  -4.5 dB
 12th  -4.9 dB  -3.7 dB (-61.8 dB in 2500Hz)

The trick is to duplicate the VLF into 2 channels,
one channel triggers the blanker, the other channel
gets the blanking.  Different filter settings on
each channel.   3kHz b/w on the triggering channel,
1kHz b/w on the channel to be blanked.   I think
there's still more to be gained but it takes a long
time to trial all the permutations.

> i tried to install vlfrx-tools on my Raspi today!

Don't be too disappointed. The USB on RPi is rubbish.
An old laptop would do better.

--
Paul Nicholson
--