[Elecraft] RTTY Interface for the K2

[sheajohnw at aol.com]

I have made about 9,000 RTTY QSOs with my K2/100.

I use an MFJ -1275 interface.  The audio output is fed from the MFJ-1275 into the K2 microphone jack.  I use an IBM clone running MS Windows XP with an iMic attached to a serial DB-9 jack RS-232 port.  The iMic replaces the sound card.  The iMic has audio in and out jacks that are connected to the MFJ-1275 using audio cables.  The speaker output jack next to the K2/100 fan is connected to the MFJ-1275.  

I use a USB adapter to connect my computer to the MFJ-1275 which serves to trigger the PTT.  The K2/100 is controlled by the computer through a second USB adapter.  It is important to remember that the control cable for the K2/100 is a custon pinout, a standard serial cable will damage the K2 if connected to what looks like standard serial ports.

I have tried HRD and it works, but I mostly use Mixw 2.20.

I set "rttY On" and use RTTY mode, the small "r" with the bar over the "r".

I set the disolay to ALC and try to allow only 1 flickering bar in the display.

I set the AGC off and control volume with the RF Gain knob.  I use the AFil rather than XFil to avoid the slight frequency shift that occurs when engaging the XFil.  AFil and XFil are normally set to 1, but I will narrow down AFil when needed.  I keep the fan set on high when operating RTTY, but do not challenge heat control a lot because I mostly operate S&P rather than Run.  My antenna is a fan dipole up about 25 feet, so I do not often have the power to operate run and attract much notice.

I had to place ferrites on all leads to prevent RFI from impacting my computer.

HTH de KB1IKD.