As far as I know , only wspr and ros-mf have the ability to drive a
pic/dds vfo , with only mf-1/7 giving a tailored mf qso mode ?
mf-1 is quoted round -35 db noise floor , in tests with my 500K 35 ft
'pine needle' Ae , over a 350 mile daylight path (1200 hrs) 150 watts
carrier produced 100% decode via the Delft web-sdr , MF-7 has a 8 dB's
degrade , so apart from the odd lock, I did not have 'quite' an extra 8
dB in the pa .. , nothing was decoded , in a sequential test, wspr
stopped decoding round 2 to 3 dB's higher than mf-1
Test set up
TX>> P4 / 4 gig > Delta 4 sound card > MA1723 exciter > 10 dB 1 dB
step atten Skanti TRP8000 250 W linear > R&S URV35 / 200 watt T power
head > 150 watts carrier > 35 ft top load vert >ref power round 1 watt in
150
RX>> Delft web-sdr > second p/c via web
After a ad hock qso on 137 with myself, The first real outing of mf-1
on 137 by Gray also produced a surprise daylight decode from Paris
with 150 watts Ae feed to short top loaded vertical array ,
Cannot here it , cannot see it , but it decodes 100 % , ' Invisible
Ros' as one our elder statesman refers to it .. worth a try over the other
side ?
G .
--------------------------------------------------
From: <[email protected]>
Sent: Thursday, August 05, 2010 11:56 PM
To: <[email protected]>
Subject: Re: LF: Fwd: CMSK Beta released
Roger,
I'm expecting great things with WSPR on 137kHz in the coming months, so
hope
I'm not going to be disappointed and hope many others will join me on
WSPR
when not busy making CW QSOs.
Please don't allow my remark to kill any interest in WSPR at 137 kHz! My
results with receiving at home have been fine at 500 kHz, and not so fine
at 137 kHz. At first I suspected Loran lines, but that turned out not to
be the issue. It appears to be due to AC-related noise in my neighborhood,
probably largely from switch-mode supplies. My own home is not the
source -- I'm guessing it's from a particular neighbor who would be very
uncooperative. As she's fond of taking people to court, I'll omit the
details in a public forum!
The noise level still permits the use of weak-signal modes like QRSS,
WOLF, and so forth, but WSPR just seems to hate this stuff. W1VD has a
much quieter site, and has not experienced the problem.
So, your results may vary, and hopefully your winter season will be
WSPR-quiet.
John, W1TAG
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