Folks,
I have just completed the KIO2 option for my second personal K2, and during
the process I pondered the problem of accidently connecting the KIO2 to a
regular computer serial cable (it does produce BAD THINGS for the health of
a K2).
I believe I have come up with a 'cure'. -- a 'dongle' for my KIO2..
I made up a short cable (6 inches long) - with connections just like
pictured in the manual, EXCEPT that I connected the shield to pin 1 on both
ends, and used slightly different backshells for the connectors. On the K2
end, I used a backshell from my junque box with screwdriver fasteners rather
than the more easily removed thumbscrews, and at the other (free) end, I
fastened two short 4-40 threaded male/female standoffs to the DB9 plug with
small nuts so I could fasten another (longer) cable. I had to cut out a
small bit of the plastic shell to allow clearance for the nuts, but it
worked. Any Elecraft external devices (in my case an externally mounted
KPA100) should be wired in the connector at the K2 end of this 'dongle'.
This 'dongle' is permanantly attached to my K2 (at least it takes another
tool to remove it), and the normally wired K2 KIO2 cable connects to the
computer. In case a standard computer cable is plugged into the end of this
'dongle', no harm will come to the K2 because the only RS232 level signals
that will reach the K2 are TXD, RXD, signal ground and frame ground. Since
the K2 does expect these signals to be RS-232 levels, they will be piped
through, but all other standard RS232 signals are blocked because there is
no connection.
The only drawback to using a standard RS232 cable with this 'dongle' is the
frame ground connection - some cables are not shielded and have no
continuity for pin 1, while others use only a wire connection between the
ends for pin 1. For RF pickup reduction the cable should be shielded and to
prevent ground loops, pin 1 should only be connected at the K2 end. The
normal K2 to computer cable detailed in the KIO2 and KPA100 manuals
accomplish this shielding without inducing ground loops.
73,
Don W3FPR
Life is what happens when you are making other plans
_______________________________________________
Elecraft mailing list
Post to:
[hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
http://mailman.qth.net/mailman/listinfo/elecraft
Help:
http://mailman.qth.net/subscribers.htmElecraft web page:
http://www.elecraft.com
Locked
