Hi Roelof
That would appear to be the first in, taking the +2 hour from the EA
data base 'off , matches up with the 'dot on the plot' , showing round
0120
2017-04-16 03:15:13 VO1NA AA PA0RDT JO11TM 0 477 -25
Op8_||||||||||||||_~25dB 2017-04-16
03:15:13 VO1NA AA F5WK JN18HP 0 477 -37 Op8__~38dB 2017-04-16
03:15:12 VO1NA AA PA1SDB JO33KH 0 477 -27 Op8_||||||||_~28dB
Ok on the filter , as long as it helps , racal went for wide band ,
anything tuned in the Ae cct degrade's the s/n, probably why the quest
for wide dynamic range , its true , using the pre-selector on the 1778
, raises the noise floor, the published Rx specifications , where in
wide band , in fact the pre-selector on the 1771/1772 was an option fit
and totally missing from the later models .
Hopefully might see some other Op8 / op36 from across the pond , in
the time to come..
73-Graham
G0NBD
--------------------------------------------------
From: "Roelof Bakker" <[email protected]>
Sent: Sunday, April 16, 2017 4:25 PM
To: <[email protected]>
Subject: Re: LF: 2017-04-16 03:15:13 VO1NA AA PA0RDT JO11TM 0
477 -25Op8_||||||||||||||_~25dB
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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