[Elecraft] Elmer Question - psk31 and the K2

[Tom Mc]

Hi all,

 This is more of an Elmer type question than anything else, so thanks in
advance for your help and also for your patience.

  I recently completed installing the KSB2 adapter to my K2 (s/n 1103).  I
now want to work psk31 and have a RigBlaster which I used for psk31 on my
other rig (FT-990) with no problem.  I was able to re-configure the
RigBlaster so that it works just fine with the K2.

  My question revolves around an article (?) posted to the Elecraft web site
by Glen Maclean WA7SPY entitled "The basic set up for your K2 to run PSK31".
Its a very good article and quite easy to follow, from my point of view,
Glen did an excellent job.  However, one comment which Glen makes I don't
follow.  He is suggesting that the user make a cable using a shielded single
wire.  Here's what he says to do:

     " Wire up one end of your cable with a 10K resistor in series with the
end of the resistor going to the audio in pin of the K2 microphone plug.
Then wire a 1K resistor from the audio in end of the 10K resistor to the K2
mic plug ground pin."

He gives a very descriptive drawing of this and it is quite clear what he is
saying and how to make the cable.  But then he goes on to say:

    "The reason for the resistors is a 100 to 1 or better voltage divider is
required so the sound card from your computer does not get overloaded and
damaged"  This is the part I don't follow.  If I'm following this correctly.
I am taking the audio OUTPUT (the speaker connection) of the computer's
sound card and feeding it to the K2's microphone input, so the data can be
transmitted.  If this is true, how could the sound card get damaged?  Isn't
the cable carrying the  audio "out of" the computer?

    In all likelihood I am missing something, as guys like Glen certainly
know a lot more about these things than I do.  If someone could set me
straight, I'd appreciate the help.

Also, of course, I read Glens write up AFTER I had already tried running my
software (Digipan, BTW), so who knows what my sound card looks like (But I
am still driving the rig, at least according to the RF indicator).

Thanks for any help you may offer,

Tom McCulloch, WB2QDG
K2 s/n 1103