[Elecraft] interfacing with K2

[K. Rice]

Hi Slater,

>  Question(s)
> -is anyone out there running a similar physical setup?
> -Successfully?

1. K2 with KIO2, KDSP2, KSB2, KNB2
2. Mac Mini OS X 10.4.6
3. Rigblaster Plus
4. Keyspan USB to dual serial port with Mac OS X drivers. (This is 
the one that works right. I suggest that you NOT substitute a
USB-to-serial adaptor from another company.  Be sure to get
the Mac-specific dual serial port with driver disk.  Keyspan
also makes ports for PCs.

(No affiliation with Keyspan. It's just the only I tried that works well.)

> -what program(s) do you use for digital modes?

Cocoamodem 2.0 with CocoaPTT.  I tried four of them and this one seemed
to work best at least in my hands.  Cocoamodem handles RTTY and PSK31
modes.  CocoaPTT is a little program that sits on one of the Keyspan
serial ports and asserts the DTR line whenever Cocoamodem wants to key 
the K2 (to begin ssending PSK31).  I have CocoaPTT in my startup file
so that it starts whenever the Mac is rebooted.  Note that the Mac
(mine at least) boots up with DTR asserted.  You have to use
The CocoaPTT control window to turn it off after you reboot, or
you'll key the K2. 

You need to make a cable to go from CocoaPTT's serial port (DIN-8) to the
serial jack on the RB+ (DB9S).  Connect only the DTR pin and signal
ground. Most everyone makes this cable by buying a Mac printer cable,
cutting it in half and mounting a DB9P plug (from RS) on the cut end of one of
the pieces.  You should mark this cable clearly or even key it somehow
to make certain that it is NEVER plugged into the KIO2.   

  http://homepage.mac.com/chen/cocoaModemPage/index.html

> -is a Rigblaster necessary to run Mac programs?

No, but since you've got one already it would be best to use it.  
It provides various isolation circuits that improved my PSK31 
detection by comparison with straight cables.

> -how do you handle audio in and audio out? What is your cabling setup for this?

I use a Griffin Technology iMIC USB "sound card" adapter which has bona
fide line level input and outputs (more resistant to overdriving), thus
allowing the Mac to send and receive line (1V) signals instead of mic
level signals.  Other things being equal this puts your audio signal
at a much higher level than noise that gets picked up on the cables.

The best reason for Using the iMIC is that you can give Cocoamodem it's
own set of audio lines and reserve the internal audio lines for music
or whatever.  This goes a long way toward assuring that you don't
inadvertently play Springsteen on 14.070 MHz. 

Just hook iMic audio out to RB+'s audio input and hook the K2's 
speaker jack to iMic audio input.  I use a Y cable and an external
speaker to listen to the K2's audio.

If you do SSB, set the RB+'s jumpers up for a K2.  Plug the RB+
mic plug into the K2 and plug your mic into the RB+.  The RB+
provies automatic mic muting when it's keying the K2

After you're done, you have half a serial cable and a vacant serial
port on the Keyspan adaptor that you can use to run MacLoggerDX from
Dog Park software.  It's a logging, QSL, contest, rig control, etc 
program supports the K2 and that is more than worth the $90 or so 
that it costs.

No affiliation with the companies mentioned above.

73
Ken