[Elecraft] K2 and RTTY - a few questions

[Don Wilhelm]

Andy,

It all depends on the software application are you using for RTTY? You 
are using MMTTY which displays the frequency the K2 is tuned to (without 
the audio offset considered).

With the RTTY filters, just like the SSB filters, the K2 dial indicates 
the suppressed carrier frequency, and you are sending AFSK tones 
centered around 1000 Hz.  That means your actual signal is 1000 Hz away 
from the K2 dial indication.  The cluster spots are giving the actual 
signal frequency.

If you were using a software application with a waterfall display (such 
as Fldigi or HRD/DM780) you would see the actual signal at 1000 Hz on 
the waterfall, and if you have the K2 to application set up right, the 
actual frequency would be displayed on the waterfall.

As far as having to switch to RTTYrev for 15 meters and above, I thought 
the K2 automatically compensated for th sideband switch.  It does that 
for SSB, but I don't know about RTTY, I have never checked.  The K does 
remember the mode on a per band basis, so once you are set up, it should 
be transparent for operation.  The mixing scheme changes at 15 meters, 
not 20.

73,
Don W3FPR

On 2/11/2013 11:54 PM, Andy, KU7T wrote:
> I literally worked my first RTTY QSOs ever last weekend in the WPX RTTY
> contest. Was a lot of fun.  A few question come up.  I have aligned my
> filters according to the well written document of Don, W3FPR at
> http://www.mail-archive.com/elecraft@mailman.qth.net/msg103915.html.  And I
> seemed to have done it right, because switching through the filters does not
> move the signal, just tightens the roll off.
>
>   
>
> Question 1: My frequency is 1000Hz off compared to what DX cluster spots
> show.  When I see  a spot at 14.077 it, is for at 14.078. This must have to
> do with the fact that the filters centers at 1000Hz, but is there a way to
> compensate somewhere for this? Would be nice to be able to use the band map
> of my contest program to jump to stations I would like to work.
>
>   
>
> Question 2: I noticed that 15m and up, I had to put both MTTY and the K2 in
> RTTY reverse.  Is this correct? I happen to remember that the switch to USB
> from LSB happens on 20m. Now I am wondering if this is something special for
> RTTY or not.
>
>