Hi Ken and LF
From my experience Winrad is not suitable for VLF
reception. The fact that Dennis M0JXM can receive Chris
(G3XIZ) on Winrad is that their aerials nearly touch (an
exaggeration) but its about 1.5km separation. Dennis can read
Chris real time. I have looked at the 9kc/s spectrum using
Winrad but I could not get the band spread or the level of FFT
iterations to resolve a signal as weak as Chris'. (I am sure
some one tell me I am wrong). However all is not lost, Spec
Lab is a free down load and runs on most Win OS. With Spec lab
you can get down to mHz BW and have a 1 or 2Hz total display
where the doubt and uncertainty are removed as to what signal
you are getting. Not only that the frequency calibration can
be automatically locked to one of the Mil stns further up the
band.
I have spent ages trying to get a good signal from the low
power VLF signals and I don't think it is easy, as Eddie and
Stefan and Marcus will tell you because I have bothered them
about it.
Where I live there are signals many many times stronger
than Chris barely 1/2Hz away. When observe at the resolution
required they appear very unstable whereas Chris' signal does
not. It becomes obvious what you are looking at. By the
stability standards required those very strong traces you are
looking at are very unstable. They emanating from only a few
yards away unless they can be identified as say a Mil stn or
Line time base they are likely to be SMPSU or the like..
The beauty of Spec Lab is that you can use some one elses
settings to get pretty well there. Stefan and Eddie have
done a lot on this, they have hepled me no end. So if you
haven't started with Spec lab I think it would be worth your
while and drop Winrad for this application. IMHO Winrad is a
great SDR application and I recommend it to any one who is
starting using SDR but I really don't think it can cut the
mustard on VLF. It's Horse for Courses Ken.
73 es GL Pete M0FMT IO91UX
From: Ken
<[email protected]>
To:
[email protected]
Sent: Mon,
2 May, 2011 11:22:49
Subject:
LF: Winrad calibration
VLF.
How can I calibrate Winrad 1.6? I am
seeing a trace at 8.99kHz, not sure if it is Chris with
Winrad requiring calibration or something else. Still
seeing the trace at 9.96 kHz, it is coming down the
antenna I can see it on the doublet with the E-probe psu
switched off so must be a high level being just a single
trace unlikely to be an SMPU?
73.
Ken
M0KHW
