[Elecraft] RTTY Questions

[Fred Jensen]

In an SDR radio such as the K3, the SSB signal is "perfect", in that 
there is no suppressed carrier leakage because there never was a carrier 
in the first place.  Properly adjusted, the audio distortion in the SSB 
signal is negligible.  As a result, there is essentially NO difference 
between AFSK and FSK in terms of transmitted signal.  No one listening 
to your signal can tell that you are AFSK or FSK and "good enough" is 
meaningless.

There are some possible local advantages to AFSK if your hearing 
resembles mine.  I use a pair of stereo cables from Radio Shack [$3.99 
each if I remember right] between the line in/out on the K3 and line 
out/in on my laptop, K3 in AFSK mode.  I run N1MM in contests with 
MMTTY, but other loggers interface to the MMTTY engine fine.  I can't 
hear anything at all around 2 KHz even though my digital hearing aids 
are running at afterburner-roar at those frequencies.  The K3 lets me 
choose from four pitch frequencies, I use the lowest at 915 Hz, and just 
have to make sure that's where MMTTY is set.  People who can hear 2 KHz 
tell me that it's really tiring and they prefer lower tones as well.

With the P3, I've found I *almost* don't have to listen to any tones. :-)

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2012 Cal QSO Party 6-7 Oct 2012
- www.cqp.org

On 4/18/2012 12:03 PM, Dave wrote:

>I am using AFSK, but plan to
> switch to FSK if I decide to do very much RTTY.  Many friends tell me
> FSK is best, a few say AFSK is "good enough".