[Elecraft] K2 auto-detect feature

[W3FPR - Don Wilhelm]

Lou,

It is likely that you can simply parallel the devices (connect to the K2 DOT 
input) and set the K2 for 'INP Hand', as long as one device does not 
interfere with any of the others.

Before attempting it, do check for the presence of voltage from each device 
to be connected.  If you have any voltage present, you may have to make some 
alterations.  Ideally you should have an open collector transistor (or relay 
points) driving the output line (this is the case on most keyers or computer 
interfaces, but it is worthwhile checking to be certain).  You should be 
able to connect from 4 to 10 open collector devices in parallel without a 
problem - the actual number will depend on the driving transistor in each 
device and just how much leakage current they have (collectively).

73,
Don W3FPR


----- Original Message ----- 
From: "Lou Roux" <laroux at bak.rr.com>
To: "Bob Tellefsen" <n6wg at comcast.net>
Cc: "Elecraft Reflector" <elecraft at mailman.qth.net>
Sent: Thursday, October 21, 2004 12:38 PM
Subject: Re: [Elecraft] K2 auto-detect feature


> Hi guys,
>
> This discussion reminds me of something I've been wanting to for a while. 
> I don't use the internal keyer in the K2 but prefer my
> own keyer and I'd like to parallel my computer/cw keyboard with it. What 
> kind of circuit would this require or could I just parallel
> the lines together?
>
> Thanks,
>
> Lou - W6UR
> K2/100 #3578
>
>
>
> Bob Tellefsen wrote:
>
>>Vic
>>I built a little keying adapter in a small can to do this.
>>It has two jacks, one for my paddles and one for the
>>keying lead from my TR Log laptop.  The laptop jack in mono, and the 
>>paddles jack is stereo.  The output is
>>a three wire lead to the key jack in the K2.
>>
>>Inside the can are the two diodes that steer the single
>>keyline from the laptop to both the dit and dah lines
>>to the K2.  The paddles connect direct to the dit and dah
>>lines.  It's been working just fine at any speed I can handle.
>>
>>
>
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