PSN-L Email List Message

Subject: Re: Re: WinSDR Wireless Interference?
From: dave.nelson@...............
Date: Tue, 13 Sep 2011 13:04:51 +1000


Hi Robert 
             strange problem,  I also wouldnt suspect the VERY low power from Wi Fi to cause a problem, its less than 1Watt. With all my amateur radio gear in my shack with power levels from 10W to 150W  it has never caused the A-D board to loose connection with the SDR computer. The worse that happens, particularly on frequencies less than 450MHz is that I get big spikes ( up to ~ 2000 data points) on the SDR trace as the cable from the sensor to the preamp acts as an antenna and picks up induced RF. I dont see any of those problems on the 1.2, 2.4, 5.7 or 10GHz bands.
WiFi is on 2.4GHz

  Loosing all traces infers that either the A-D card is loosing power or there is a connection problem between the A-D card and the SDR computer.
Will be interesting to see what the eventual cause and remedy is  :)

cheers
Dave N
Sydney


> Robert Thomasson  wrote:
> 
> Jerry,
> 
> Thanks for your reply.  No, there is not a totally blank screen.  The 
> WinSDR
> screen stays there but there are no seismometer wiggles (hope we're not
> losing our layman audience here)  on it.  There are no lines at all, no
> straight lines and no seismo wiggly lines.  I have to reboot WinXP to 
> get it
> up and running again and when it comes back, there are the straight 
> green
> lines for the time period that WinSDR was having it's problem.   But 
> again,
> when the problem happens there are no lines at all, just the blank 
> WinSDR
> system window as if I'd opened the program without a seismometer 
> connected.
> 
> I have checked the cable connections and all other connections literally
> dozens of times and I also don't get the same symptoms of a blank WinSDR
> screen when I disconnect a cable.
> 
> When WinSDR goes into its problem mode, I can't just close it and 
> re-open it
> to get it running again.  It will open but not connect to the seismo.  I
> have to reboot WinXP to get WinSDR running again.
> 
> I agree that it seems unlikely that it's a frequency/antenna problem but
> I've convinced myself that it only happens when the router or wireless
> computer starts transmitting data.
> 
> Thanks,
> 
> Bob
> 
> 
> 
> Now that I've gone public with this problem, I can rest assured that the
> solution will be something embarrassingly simple.
> 
> Bob
> 
> On Mon, Sep 12, 2011 at 3:40 PM,  wrote:
> 
> >   By “loosing trace”, do you mean totally blank screen or a line drawn 
> *without
> > the seismometer wiggles?*
> > **
> > I ask because I had a connection problem arise between my sensor and
> > Larry’s A/D box.  For convenience, I had added right-angle adapters at 
> the
> > box connectors.  One adapter frequently lost the connection from the 
> sensor
> > and all that was displayed on the computer was a straight green line.  
> I
> > removed the adapter and it worked fine.
> >
> > I too am using an old Dell running XP, but do have it connected to the
> > LAN.  I know that this probably does not answer your problem, but I 
> doubt
> > seriously that it is frequency / antenna problem.
> >
> > Regards,
> > Jerry Payton
> > ------------------------------
> >
> >  *From:* Robert Thomasson 
> > *Sent:* Monday, September 12, 2011 5:01 PM
> > *To:* psnlist@..............
> > *Subject:* WinSDR Wireless Interference?
> >
> >
> > I have had some trouble keeping my WinSDR up and running.  It 
> frequently
> > shows just a blank screen, with all helicord traces gone.  Just as if 
> I'd
> > just opened the software without a seismometer connected to the 
> computer.
> > The computer is an older Dell with a 2 GHz processor and 512 Mb RAM, 
> running
> > WinXP with I think service pack 3.
> >
> > What is interesting about this phenomenon is that there is a wireless
> > router in the house (the seismo server has no wireless capability and 
> is not
> > connected to the network) and WinSDR will work fine until someone sits 
> down
> > at another computer and the wireless network starts exchanging 
> traffic.
> > Then the WinSDR screen loses the displayed data and goes blank.
> >
> > Is it possible that somehow the USB cable from the seismometer to the
> > seismo server computer  is acting as an antenna and picking up enough
> > interference from the 2++GHz wireless LAN system to crash WinSDR?  
> WinSDR
> > does not actually crash, it just loses the data traces, which 
> disappear.  My
> > next step is to dig out some old books and see if I can figure out 
> what
> > length the seismo cable would have to be to resonate at the wireless 
> LAN
> > frequency.   But I think it would have to be very short?
> >
> > This is another unexpected educational aspect of this hobby!   Just
> > wondering if anyone else has experienced this issue?
> >
> > Thanks,
> >
> > Bob
> >
> >
> >
> >
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