FW: [Elecraft] Spectrogram plot interpetation

[Jim Brown]

On Sat, 3 Jan 2004 09:18:06 -0500, Dan Barker wrote:

>Is it 60 Hz hum? 

I suspect that the larger one is, and that the smaller one just to the
right of it is either 120 Hz or 180 Hz.

>Why is it even there?

It is quite common for there to be hum on the interface to a sound
card. Some causes are a pin 1 problem in the sound card, or IR drop on
the shield a difference in the ground potential between the computer
and the ham rig.

For purposes of tuning your radio, you can ignore it.

Jim K9YC

Jim Brown
Audio Systems Group, Inc.
Chicago
http://www.audiosystemsgroup.com