[Elecraft] KIO3B: Another great Elecraft upgrade

[Bruce Nourish]

Hi folks,

Last night I performed the KIO3B upgrade on my new (old) K3. As with all
Elecraft projects I've done, documentation was great, and things work as
expected. A few minor things needed some thinking:

* I forgot to upgrade the firmware before installing it, but I was able to
get the right firmware version loaded over USB by toggling the KIO3B into
RS232/legacy mode.

* A hidden end of one of the TMP cables got loose while I was putting
everything back together, which caused an easily-fixed ERR PL1.

* The lack of sound scared me for a minute, but then I found the very last
instruction, to toggle the KIO3B speaker -/+ setting, and that fixed the
sound.

This is the neatest digital-capable ham shack I've ever had, and I'm
already happy I installed it. Thanks, Elecraft folks.

Bruce