[Elecraft] K2 RTTY

[Don Wilhelm]

JT,

There is nothing wrong with AFSK - in fact, if the carrier balance on 
the KSB2 board is adjusted correctly, AFSK is indistinguishable from FSK.

The only 'problem' with the K2 is that the BFO range is limited, with 
the result that narrow filters cannot be set with a center frequency 
equal to the 'true RTTY' tones.  MTTY and other soundcard RTTY programs 
offer a selection of tone frequencies - so if you align your narrow RTTY 
filters to at 800 or 1000 Hz, MTTY can accommodate that center 
frequency.  When I set up RTTY filters on a K2, I set the FL1 filter the 
same as the SSB filter and then set FL2 at 1.00 kHz, FL3 at 0.70 and FL4 
at 0.400.  The narrow filters are centered at either 1000 Hz (or 800 Hz 
if the BFO range will not accommodate 1000 Hz for the 0.40 filter on 
both sidebands).  In operation, the RTTY signal is tuned to center on 
1000 Hz (or 800 Hz) and the program will decode the signal - 
transmission will occur at the same offset and noone on the receiving 
end will know whether you are using real FSK or AFSK.

So the short answer is: the K2 will operate just fine on RTTY, and yes, 
you can use narrow RTTY filters to minimize the QRM.

73,
Don W3FPR

John Tobias Croteau wrote:
> How well does the K2 work in RTTY mode?  I presume it is AFSK only?  I
> seem to recall that some do not recommend the K2 for serious RTTY
> operating but I don't remember the reasoning behind this.  I vaguely
> recall reading this about 2 years ago from somewhere.
> 
> I'm a RTTY operator first then SSB.  I've never been good with CW and
> probably never will so I focus on these two modes.  I know it's a poor
> attitude but let's just not go there, at least I am honest about it.
> Most of my RTTY operation is centered around contest weekends simply
> because I can only operate portable due to antenna limitations at the
> home QTH.  However, I am not a hardcore contester.  I merely operate
> during the contests to maximize QSO numbers although getting a good
> score never hurts.
> 
> Around August, I'm finally going to be able to upgrade to something in
> the K2 price range.  Will the K2 be acceptable for the way I operate
> RTTY or should I hold out for a K3?  I know the K3 will be a much
> better data rig.  I can't really afford a K3 but I could probably make
> it happen.
>