PSN-L Email List Message
Subject: Re: WinSDR Wireless Interference?
From: Christopher Chapman chrisatupw@.......
Date: Tue, 13 Sep 2011 18:52:03 -0400 (EDT)
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 audienc=
e 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 w=
hen it comes back, there are the straight green lines for the time period t=
hat WinSDR was having it's problem. But again, when the problem happens t=
here are no lines at all, just the blank WinSDR system window as if I'd ope=
ned the program without a seismometer connected.
I have checked the cable connections and all other connections literally do=
zens of times and I also don't get the same symptoms of a blank WinSDR scre=
en when I disconnect a cable.
When WinSDR goes into its problem mode, I can't just close it and re-open i=
t to get it running again. It will open but not connect to the seismo. I =
have to reboot WinXP to get WinSDR running again. =20
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 comput=
er starts transmitting data.
From: Robert Thomasson=20
=20
I have had some trouble keeping my WinSDR up and running. It frequently sh=
ows just a blank screen, with all helicord traces gone. Just as if I'd jus=
t 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 W=
inXP with I think service pack 3.
What is interesting about this phenomenon is that there is a wireless route=
r in the house (the seismo server has no wireless capability and is not con=
nected 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 seism=
o server computer is acting as an antenna and picking up enough interferen=
ce from the 2++GHz wireless LAN system to crash WinSDR? WinSDR does not ac=
tually 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 s=
eismo cable would have to be to resonate at the wireless LAN frequency. B=
ut I think it would have to be very short?
Hi Bob,=20
Can you tell us what electronics are connected to the various computers=
, including modems, please?
Are all the computers properly earthed, please? =20
The velocity of light is about 300 million metres / sec, so the wavelen=
gth is likely to be 12.5 cm. Put a ferrite ring on the SDR data cable and s=
ee 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 prio=
rity program were on the same port / channel and the reception of the radio=
signal, or one from a modem, just switched the data source.=20
Regards,
Chris Chapman=20
=20
=
Subject: Re: WinSDR Wireless Interference?
No, there is not a totally blank screen. The WinSDR screen stays ther=
e but there are no seismometer wiggles (hope we're not losing our layman au=
dience here) on it. There are no lines at all, no straight line=
s 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 f=
or the time period that WinSDR was having it's problem. But aga=
in, when the problem happens there are no lines at all, just the blank WinS=
DR system window as if I'd opened the program without a seismometer connect=
ed.
I have checked the cable connections and all other connections literally do=
zens of times and I also don't get the same symptoms of a blank WinSDR scre=
en when I disconnect a cable.
When WinSDR goes into its problem mode, I can't just close it and re-open i=
t 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 comput=
er starts transmitting data.
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 wit=
hout a seismometer connected to the computer. The computer is an olde=
r Dell with a 2 GHz processor and 512 Mb RAM, running WinXP with I think se=
rvice pack 3.
What is interesting about this phenomenon is that there is a wireless route=
r in the house (the seismo server has no wireless capability and is not con=
nected 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 seism=
o server computer is acting as an antenna and picking up enough inter=
ference from the 2++GHz wireless LAN system to crash WinSDR? WinSDR d=
oes not actually crash, it just loses the data traces, which disappear.&nbs=
p; My next step is to dig out some old books and see if I can figure out wh=
at 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 electronic=
s 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 t=
he seismometer computer does NOT have a radio module fitted, please?
The effects you describe might be explained if WinSDR an=
d a higher priority program were on the same port / channel and the recepti=
on of the radio signal, or one from a modem, just switched the data so=
urce.
Regards,
Chris Chapman
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