Happy Easter too , Joe
Thought there was a delay , )
Well tonight , your being spotted by LA3EQ , first off at 22:45 ,
just about at the limit of the op8 range , may be 1 dB short , but
after that , every tx ? , definite positive trend in the s/n , conditions
seem to change quite quickly , just spotted by pa0rdt at 00:00 @ -30 dB
, no dynamic spots before this ..
Now 'we can see how narrow the window is , for TA on 502 , luck to
make the CW contacts with gb4fpr !!
73-Graham
G0NBD
00:00 477 VO1NA de PA0RDT Op8 -30 dB F:12% in Middelburg 1482,4 Hz
00:00 477 VO1NA de LA3EQ Op8 -30 dB F:8% in Egersund 1479.0 Hz
23:45 477 VO1NA de LA3EQ Op8 -29 dB F:2% in Egersund 1479.0 Hz
23:30 477 VO1NA de LA3EQ Op8 -32 dB F:5% in Egersund 1479.0 Hz
23:15 477 VO1NA de LA3EQ Op8 Deep Search -35 dB in Egersund 1479.0 Hz
22:45 477 VO1NA de LA3EQ Op8 Deep Search -38 dB in Egersund 1479.0 Hz
--------------------------------------------------
From: <[email protected]>
Sent: Sunday, April 16, 2017 10:55 PM
To: <[email protected]>
Subject: Re: LF: 2017-04-16 03:15:13 VO1NA AA PA0RDT JO11TM 0
477 -25Op8_||||||||||||||_~25dB
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
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