[Elecraft] How do you get N1MM to send CW to the K2?

[Vic K2VCO]

It's not that bad! The ALC line coming from the DB9 connects to nothing until it gets to 
the control board. There is one trace to cut there, and then the four additional 
components can be placed against the board. You can connect to the key inputs right there. 
It is very neat, all on the control board.  All you give up is the ALC input. You don't 
mess with any of the other lines.

Yes, you need to use a cable with an additional wire.  And yes, it might be bad if you 
don't cut the trace (or if you cut the wrong one!)

I deliberately gave sketchy instructions, but if I can find the photos I took of the 
board, I'll write it up and put it on my website.

On 11/15/2011 8:36 PM, Don Wilhelm wrote:
> I would like to point out that Vic's solution will require an extra wire
> in the "special cable" that is constructed for the K2 to com port.  The
> normal cable carries only the RXD and TXD signals (plus signal ground) -
> there is no wire for DTR (or alternately RTS).  While Vic's solution can
> work (and work as well as any DTR keying from a computer), it is not
> something to be attempted by those unfamiliar with the internal K2
> signals present at the DB-9 connector nor those unfamiliar with RS-232
> signal lines and the "one transistor keying interface".
>
> If you understood and followed all of that, yes, you can do it too - but
> if you did not understand those skimpy instructions, be aware that you
> can damage you K2 if you do not understand the signals involved.  This
> is not a modification that can be installed "willy-nilly", it must be
> done with care to divorce the normal K2 signals to the DB-9 connector
> and add the keying circuit.
>
> 73,
> Don W3FPR
>
> On 11/15/2011 11:01 PM, Vic K2VCO wrote:
>> What I did with my K2 was disconnect the ALC input line to the DB9 and use that for DTR,
>> since even if I did operate SSB I would not use ALC!
>>
>> I connected this pin through a 1k resistor to a the base of an NPN transistor, grounded
>> the emitter and connected the collector to a pair of diodes which go to the dit and dah
>> lines of the K2's key input.  Then I turned the autodetect feature ON in the K2, and set
>> N1MM for DTR keying.
>>
>> The radio works normally with either a paddle or a straight key as well as the computer,
>> and no extra wires or keying interfaces to the computer are required. It was very easy to
>> hook up, and it was possible to route DTR through the same connectors from the KIO2 to the
>> Control board and onto the RF board.
>>
>>
>> On 11/15/2011 7:45 PM, Guy Olinger K2AV wrote:
>>> You will have to use a different com port on the computer which goes to a
>>> level converter circuit.  That in turn will need to go to the K2's key
>>> jack.  There is no way with a K2 to use RTS or DTR for PTT and CW keying as
>>> on the K3. DTR and RTS are not recognized on the K2, with those pins in the
>>> DB9 jack used for proprietary purposes, including the K2's internal bus.
>>>
>>> There are also issues with direct keying from a PC, usually irregular
>>> spacing or what some call "jumpy" CW.  This is caused by a PC's
>>> multitasking.  A lot of us, including myself, have gotten around all of
>>> this by using a Winkey box, or a utility box that embeds the Winkey chip.
>>>     Microham devices embed the Winkey chip.  N1MM can be told to look for a
>>> winkey device on the end of a com port, and will properly drive it.  The
>>> box in turn provides the correct interfacing to key the K2's key jack,
>>> including for some of these boxes a pair of transceivers in SO2R.
>>>
>>> 73, Guy.
>>>
-- Vic, K2VCO Fresno CA http://www.qsl.net/k2vco/