My last post -Re: [Elecraft] KIO2 cable question

[Don Wilhelm]

Sorry folks, I had a senior moment - pin 1 is Data Carrier Detect for the 9
pin connector, it is pin 5 that is signal ground - the connector shell is
chassis ground.

On the 25 pin connector, pin 1 IS chassis ground and pin 7 is the signal
ground.

73,
Don W3FPR

----- Original Message -----
From: "Don Wilhelm" <w3fpr@peoplepc.com>
To: "Vic Rosenthal" <rakefet@rakefet.com>; "Elecraft"
<elecraft@mailman.qth.net>
Sent: Monday, May 20, 2002 6:32 PM
Subject: Re: [Elecraft] KIO2 cable question


> Vic,
>
> As a first suggestion - run the pin 1 shield connection through the
> switchbox, but do not ground the shield AT the switchbox chassis - you can
> bypass it with a capacitor.  Do ground the case of the switchbox to your
> station ground.  That will give you the continuous 'ground' (actually
> common) that you need while preventing ground loops.
>
> This is a case where what we usually refer to as 'ground' is really a
signal
> path - In the 'old days' I worked some with large computer controllers and
> associated terminals - the same rule applied -- connect the cable shield
to
> round at the source device and nowhere else in the system (but at all
other
> places consider it as a signal wire to be connected).  Be careful that the
> devices you connect are constructed so that the isolated common connection
> is feasible - many will connect the shield to their own ground inside the
> box.  If that is the case, some rework of that box may be in order.
>
> 73,
> Don W3FPR
>
> ----- Original Message -----
>
> > The manual says that the cable from the KIO2 to the serial port should
> have the
> > ground braid connected only at the rig end.  I presume that this is to
> avoid a
> > ground loop that could result in RF pickup.
> >
> > I am intending to connect my KIO2 to a switchbox so that I can connect
> either
> > the rig or a packet TNC to the single serial port on my laptop.  If I
> don't
> > connect the ground at the switchbox, then the box itself and the cable
to
> the
> > computer will be floating with respect to the rig and the computer.
> ....snip
>