Hi Roelof, G.. and Group,

The delayed curtain up on the opera was due to VLF tinkering.
There was much excitement when a pc with a properly working
sound card was deployed. Today I resurrected the low 100m aerial
(Happy Easter to all) and fed 30 watts 200ma on 8277 and
got some lovely -60 dB readings at 1 km.  Then the coil arced.
A far field detection was almost a certainty up to this point!

OP8 on 479.477 kHz will resume at 2200 tonight. Good luck
to all and keep up the good work with the RTL Roelof and
thanks for the reports Graham.

73
Joe

On Sun, 16 Apr 2017, Roelof Bakker wrote:

Hello Graham,

Thanks again for the reception overview.

Lack of reception at the start might have been due to severe static.
See the attached Linrad overnight plot of VO1NA.

I have changed the front end filtering for the RTL SDR V3. It now
consists of a double tuned band pass filter with a -3 dB bandwidth
of about 12 kHz (loss 6 dB), followed by a tuneable pre-amplifier
with a gain of 20 dB.

I have measured the sensitivity of the RTL SDR V3 dongle. At 477 kHz
the MDS is -121 dBm in a 500 Hz bandwidth. At 100 kHz the MDS is -93
dBm.

73,
Roelof