[Elecraft] RTTY via FSK-D

[Ed Muns]

> First off how do people usually drive this signal?  I assume 
> its usually taken off of a serial port...  I've tried a few 
> RTTY apps and I've gotten them all to work via AFSK and all 
> seem to have their pros/cons.

The most common way, and compatible with most loggers and RTTY software, is
to drive the K3 FSK and PTT lines on the AUX connecter from a serial COM
port on the PC.  All that's needed is a level shifter from the PC RS-232 to
the K3 TTL.  Use a 1-2Kohm base resistor and an NPN switching transistor in
the FSK and PTT lines.  A diagram of this (except for the K3 AUX connector
pins which is in the K3 manual) can be found many places, including
www.rttycontesting.com.

> I have a feeling in the end that I'll probably most use MMTTY 
> being that it has a very nice interface into N1MM (unless 
> there is another application that has a nice interface into 
> N1MM that I should be aware of). 

In the recent RTTY Contesting Survey just completed, 75% of the respondents
use MMTTY.  Look no further.  It is beautifully integrated with N1MM Logger.

> Finally my last question is that if this comes off of a UART 
> how has the timing been for people?  I remember a while back 
> I used a UART to to CW keying in N1MM.  I remember being 
> embarrassed by the CW that was sent and I've since bought a 
> K1EL WKUSB kit and put that together...  Very happy with that 
> little box.  Would I have these same timing issues in this 
> FSK_IN setup?  If there was ever a stupid thing is trying to 
> use Windows as an RTOS. ;)

Timing is perfect.  I've never heard of a problem, especially because of the
UART in the PC.

Ed - W0YK
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Ed Muns
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