I think it is not wise to use a wireless
connection for anything critical.

It would be best if all connections
were optronics in nature.

Sounds to me like a hardware or software issue.

You can never rule out human interference
when doing general things which can come from
anywhere at all.

regards,
geoff
----- Original Message ----- 
From: "Christopher Chapman" 
To: 
Sent: Tuesday, September 13, 2011 3:52 PM
Subject: Re: WinSDR Wireless Interference?






Subject: Re: WinSDR Wireless Interference?


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.






From: Robert Thomasson





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?

Hi Bob,
    Can you tell us what electronics are connected to the various computers, including modems, please?
    Are all the computers properly earthed, please?
    The velocity of light is about 300 million metres / sec, so the wavelength is likely to be 12.5 cm. Put a ferrite ring on the 
SDR data cable and see if this has any effect?
    Can you physically check that the seismometer computer does NOT have a radio module fitted, please?
    The effects you describe might be explained if WinSDR and a higher priority program were on the same port / channel and the 
reception of the radio signal, or one from a modem, just switched the data source.
    Regards,
    Chris Chapman












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