[Elecraft] K2 and Digi Modes

[Don Wilhelm]

The link I provided below for Jim Brown's HamInterfacing document is 
incomplete (Blame Jim, I copied it from one of his posts :-) ).
Use http://audiosystemsgroup.com/HamInterfacing.pdf instead.

73,
Don W3FPR

Don Wilhelm wrote:
> Rudi,
>
> Take a look at the W3FPR Fixed Audio Output that can be found on Tom 
> Hammond's website www.n0ss.net.
> Unfortunately, Tom no longer offers the boards but has offered to 
> provide the PC board data to anyone who wants it.  You could easily wire 
> the circuit on a piece of perfboard.  That takes care of the output 
> (without isolation transformers), but you are on your own for the input 
> side.  If you have no need for switching between digital input and a 
> microphone, there is nothing wrong with putting a resistive attenuator 
> on the Mic AF line inside the K2 - you can easily break the line at the 
> microphone configuration header and add a couple resistors at that point.
>
> If you use RTS or DTR from the serial port for PTT, you will certainly 
> have to place the one transistor interface (or optoisolator) for that 
> outside the K2.  I guess one could butcher the KIO2 or AUX I/O internal 
> K2 signal lines on the KPA100, but that would make it unusable fo 
> connecting an external Elecraft device like the KAT100, the XV series 
> transverters or the KRC2, and I would not recommend doing that.
>
> Any isolation transformers may have to live outside the K2 if it is a 
> K2/100 - there is just not room inside.  In the K2/10 you might find 
> room for the transformers, but that depends on the particular options 
> you have installed.
>
> You may not need the transformers if you follow the guidelines offered 
> by Jim Brown W9YC - see http://haminterfacing.pdf for more information.
>
> 73,
>   
>