[WWYC] Some info please

[Fabian Kurz]

Hello,

I made such a cable by myself and it's not hard to do so. The basic circuit 
is just a transistor whose base is connected to one PIN in the Parallel or 
Serial port via a resistor. The keying-line is connected across the 
emitter-collector path of the transistor and that's it!

Here is a little example of such a circuit: 
http://www.aa5au.com/rttyinterface.html

If you prefer to have a galvanic isolation between the transmitter and the 
computer (to avoid RFI-trouble; especially usueful on fielddays etc, where 
you possibly don't have a good grounding and undefined potentials on what 
your radio thinks is ground ;), you can use a circuit with an optocoupler, 
like this:

http://www.qsl.net/ae0q/contest/opto_key.htm

It's pretty easy to build and very cheap, unlike the adapters you can buy 
which range between $10 and $25 as far as I know..

73, Fabian Dj1YFK

PS: Real CW OP's use had sent CW ;))






At 20:20 05.05.2003 +0100, you wrote:
>Hello all,
>
>I am interested in getting a link cable, so I can link my laptop to the 
>rig.  For use with CW keying in contests, dxpeditions, field days etc..
>
>I want to get one that works with programs like CT or SD etc...  I have a 
>normal laptop with the normal ports etc..
>
>What would people reccomend, and where can I buy one of these leads from????
>
>Thanks 73. Danny, M0GMT.
>
>
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