I believe Radars and Microwave ovens operate arond 2 GHz
possibly interfereing with any electronics in the 2GHz range.

A Firecontrol Radar might transmit with a Gw of power over several nano seconds.

I see radars interfereing with cable television quite often.

It shows as a periodic loss of signal every so many seconds
and here in arizona i believe it to be Aircraft
transmitting this powerful interference.

But it is only periodic and does not go on for
hours at a time.

It is a must to use a faraday shield on all electronics.
If you use a mesh the mesh size must be smaller
than a half wavelenth of the frequencies you
are trying to keepout and all leads going
through the case must be isolated too.

Any amplifier must have a LPF keeping out RFI.

If you use a post amp with a gain of one you are possibly OK
without a lot of shielding.

I see RFI as a serious issue today in Electronics.
Especially if using sensors of any kind.

Regards,
geoff


----- Original Message ----- 
From: 
To: 
Sent: Tuesday, September 13, 2011 9:24 AM
Subject: Re: WinSDR Wireless Interference?


> Hi,
>
> I have never seen this type of issue. But I use wirless all the time close
> to my geophone. I use serial cable, not usb however.
>
> Regards,
> Jón Frímann.
>
>
>> 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
>>
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSNLIST)
>
> To leave this list email PSNLIST-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
> 

__________________________________________________________

Public Seismic Network Mailing List (PSNLIST)

To leave this list email PSNLIST-REQUEST@.............. with 
the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.