Welcome, Guest

Author Topic: Noise only on the first channel of the SMT?  (Read 13689 times)

Kris

  • Newbie
  • *
  • Posts: 9
  • Karma: +0/-0
Re: Noise only on the first channel of the SMT?
« Reply #15 on: November 23, 2012, 12:20:20 PM »
Hi Ruben, I can give some advice after spending some time with the hardware.

1. Use a portable PC on battery (NOT connected to anything)
2. Skin preping is paramount: use some nu-prep (or alcohol and a bit of water on the area) THEN use some paste to "glue" the electrodes to the skin (I'm using my DIY electrodes because the Olimex are just too big, your head quickly becomes goo-land and they don't even stay in place). THIS STEP IS CRITICAL for the final result
3. Disconnect as many electrical devices in the vicinity (and switch off lights if it's possible)
4. Travel around the room with all the hardware connected on your head  and litteraly find the best spot where you're not getting those damn 50Hz!


Good luck! It works but it's not that easy.

Ruben

  • Newbie
  • *
  • Posts: 7
  • Karma: +0/-0
Re: Noise only on the first channel of the SMT?
« Reply #16 on: November 25, 2012, 01:34:09 AM »
Hi Kris,

Thank you for your help. I´ve visited a engineer and he has tested with his equipment. He has found that there was problems with usb plug and the eeg-smt was recording noise from electric network. He has installed a special ground and the signal is now better.
I m going to follow your recommendations too and I´ll tell you later.

Thank you very much

regards

Rubén

LubOlimex

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 1968
  • Karma: +50/-3
Re: Noise only on the first channel of the SMT?
« Reply #17 on: November 26, 2012, 08:14:51 AM »
Hello Kris and Ruben,

Thank you for the well-written suggestion list Kris, if you don't mind I might include it in the next revision of the manual/quickstart guide.

Ruben, please feel free to post the workaround for the noise! We would be interested in your solution and if we find it reliable we might include it in the next revision of the EEG-SMT.

Regards,
Lub/OLIMEX
Technical support and documentation manager at Olimex

Kris

  • Newbie
  • *
  • Posts: 9
  • Karma: +0/-0
Re: Noise only on the first channel of the SMT?
« Reply #18 on: November 26, 2012, 01:16:35 PM »
Hello Kris and Ruben,

Thank you for the well-written suggestion list Kris, if you don't mind I might include it in the next revision of the manual/quickstart guide.

Ruben, please feel free to post the workaround for the noise! We would be interested in your solution and if we find it reliable we might include it in the next revision of the EEG-SMT.

Regards,
Lub/OLIMEX

I don't know if my suggestion list works for anyone else but me but thanks anyway ;D

I'd be interested in hearing about that "ground mod" too

A wireless EEG-SMT powered with a pair of batteries would definitely fix this (and make life a lot easier  :) ) but it would be much more expensive I guess
« Last Edit: November 26, 2012, 01:42:53 PM by Kris »