[Elecraft] Audio interface issue.

[Dick Frey]

I have blown up computer motherboard audio line inputs on three computers
and two USB audio adapter dongles trying to run RTTY or PSK.

The Line Out is set at "nor 15". There was a direct connection from Line
out to the rear sound line in.There is a large ferrite 51 mix choke on the
cable. There was a ~20dB pad in line going to the mic input on the
dongles. The antennas are >150' away 75' up, and I am running 500W.

The line output is transformer-coupled, right? It appears there is some
sort of transient that's killing the input to the audio codecs.

Does anyone have experience with this problem?

-- 
Dick - N7XU