[Elecraft] Computer Audio Problems -- Was OT - sound cards

[Jim Brown]

On 1/9/2012 11:08 AM, Erik Basilier wrote:
> I am aware of a lot of issues that come into play when another active device
> such as a radio is connected to the computer, and I am by no means claiming
> that the digital modes setup I had was ideal an up to your standards.
> However, when a simple passive microphone capsule is connected to a simple
> unbalanced sound card microphone input, with no RF around, in what respect
> would you vary or adapt the connection? Besides impedance and level issues,
> are sound card inputs sensitive to DC resistance? What about DC offsets (the
> software offers an option to cancel such.) Could you please refer me to the
> specific tutorial, as there are so many that you have written.

The RFI tutorial has a section on Solving Problems in the Shack that 
covers this. Also the power point on Ham Interfacing.  Impedance DOES 
NOT MATTER. DC blocking is NOT required, but an electret DOES need DC 
bias to work. All that is required is the proper connection and getting 
levels right. The ham interfacing tutorial shows everything you need.

I also recently did a tutorial webinar on recording wav files for 
contesting for NCCC, our local contest club, including detailed info on 
how to set levels properly.  Problems with noisy recording are almost 
always caused by recording at levels that are far too low, or by not 
having proper bias for an electret mic.  In the webinar, I went through 
the use of simple but nice sound editing (and free) software that I 
found on the internet. I believe that there is a link to the webinar on 
the public section of the website (nccc.cc).

73, Jim K9YC