Issue - USB powered GSM Modem's Audio Out to PC's MicI am trying to record audio from

Discussion in 'Embedded Systems and Microcontrollers' started by scurrminator, Dec 13, 2011.

  1. scurrminator

    Thread Starter New Member

    Dec 13, 2011
    I am trying to record audio from the Usb powered GSM Modem's Audio Out Pin using my PC. I have used a 2.5mm to 3.5mm audio jack feeding Modem's Audio to the PC Mic interface. But I am hearing the EMI noise that usually generated when you bring your mobile in a call to an unsheilded speaker system.
    The system works well when I attach my mobile handset to the 2.5mm end of the audio adaptor and I am able to record clear audio. The issue arises when I use the gsm modem which is powered from the same PC and feed its audio to the PC Line In or the Mic. The modem I am using is Samba 55. The last image is the adapter connected to the mobile phone, works well and i am able to record clear sound. Can any one suggest how can i remove the EMI noise?
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    I've done about everything I can think of, but cannot stop my speakers from making the buzz-click-humm (sort of like old modem sounds) on my amplifier for PC speakers. I thought it was cheap amplified speakers making the noise, so I bought a complete 5.1 system with receiver for the PC.

    I still need to move the receiver at least 4 feet away to keep the buzz away. :(