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Re: LF: Winrad calibration

To: [email protected]
Subject: Re: LF: Winrad calibration
From: qrss <[email protected]>
Date: Mon, 02 May 2011 18:25:10 +0100
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Thanks for the rescue Pete

I have very little experience with Winrad. Ken uses it and understandably wanted to try with what he knows, he has Speclab and a config fie for 8.97kHz. Sounds like time for a quantum leap Ken, to start using something that is known to be ideally suitable.

Good luck.

Eddie

On 02/05/2011 17:08, M0FMT wrote:
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


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