[Elecraft] RS232 DEVICES VIA KIO3B BOARD

[KENT TRIMBLE]

The RS-232 thread comes coincidentally at a time when I have just 
experienced an RS-232 "gotcha."

If you own a Palstar AT-AUTO you need to remember that the RS-232 cable 
(null modem) originally supplied with the tuner is cross-wired (pin 2 to 
pin 3, and pin 3 to pin 2).  This is the correct wiring that allows the 
tuner to follow frequency excursions by the K3.

Recently I returned my K3 (sn 21) to Watsonville for hardware upgrades 
that included replacing the KIO3A board with the new KIO3B board (now 
standard on the K3S).  However, this new board no longer utilizes a DB-9 
connector for RS-232 functions, but instead uses a female RJ-45 socket 
for RS-232 functions.  This now renders obsolete the original 
DB9-equipped cable that came with the AT-AUTO.  Fortunately, Elecraft 
includes with the upgraded KIO3B board a pre-wired 30-inch RS-232 
cable.  This cable has an RJ-45 plug on one end and a DE9S plug on the 
other end.  Unfortunately, this cable is wired straight-through . . . no 
cross-wiring . . . which means no QSY following by the Palstar.

After spending more time than I care to admit in testing cable 
continuity, serial baud settings, and configuration menus in both the K3 
and the Palstar, I suddenly tumbled to the fact that the Palstar cable 
is cross-wired while the Elecraft cable is not.

Home-brewing a new cable with the proper wiring now permits the AT-AUTO 
to follow band and frequency changes in the K3. Unfortunately, the 
Elecraft cable uses molded connectors which prevented an easy and quick fix.

Just a tip for those who own either the original Palstar AT-AUTO or the 
newer HF-AUTO (which I presume is wired the same), or for anyone using 
RS-232 peripheral devices who want to upgrade to the new KIO3B board.  
Those pin-outs in the manuals are there for a reason!

73,

Kent Trimble, K9ZTV
Jefferson City, Missouri