Barry, thanks for remembering the other small Radio Shack 1:1 transformer for 600/ 900 ohm isolation. I was thinking of the speaker output side of sound cards being around 8 ohms, and the other side
Author: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Date: Fri, 21 Dec 2007 22:55:21 -0800
Most Virtually ALL audio circuits have low impedance outputs and high impedance inputs. They are INTENDED to be used without any form of "impedance matching" or loading. The concept of "impedance mat
The xfmr isn't for impedance matching, it's for ground isolation. 73, Barry N1EU _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/
And why does one need a transformer for ground isolation?. All of the inputs and outputs, computer and radio, are unbalanced to ground. Perhaps it is due to the systems having two different grounds,
Even when all systems are properly connected to the same ground buss, there can be slight potential differences caused by magnetic fields from transformers, and in RF transmitting systems by electrom
Author: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Date: Sat, 22 Dec 2007 12:08:03 -0800
Right. And tranformers should not be necessary if you follow the simple and inexpensive techniques in my RFI tutorial -- bond all the gear together with big copper, plug everything into the same outl
Ground issues should not be a problem. I'd say in 99% of the instances, the output of the computer sound card is unbalanced to ground. Maybe 1% are unbalanced above ground and there is a difference.