[RTTY] K3S with AFSK

[Joe Subich, W4TV]

 > 1) Are low tones OK?

Yes, if the AFSK TX Filter is enabled.

> 2) Can/should the AFSK TX 400-Hz DSP transmit audio filter, which is
> selected in the K3's configuration?

Absolutely!

> A friend just got his K3S and turning on the filter apparently
> prevented the AFSK transmission, which leads me to conclude the filter
> is designed for high tones.

Your friend probably failed to set the FSK/AFSK "PITCH" for the tones
in use.  The AFSK TX filter is centered 85 Hz above the selected MARK
tone (915, 1275, 1445, or 2125).  Attempting to use MARK other than
one of the supported frequencies (ie., "click on the waterfall") and
failing to use the selected MARK will result in no output.

The same applies to the K3 when using an external sound card.

73,

    ... Joe, W4TV


On 4/24/2017 5:44 PM, Jim N7US wrote:
> I'm replacing my K3 with a K3S and plan to use AFSK (using the internal
> soundcard) after using only FSK for many years.
>
> I prefer listening to low tones, 1225/1445.  I understand that high tones
> are recommended for AFSK to prevent the possibility of transmitting the
> second harmonic.
>
> My questions are K3/K3S specific:
>
> 1) Are low tones OK?
>
> 2) Can/should the AFSK TX 400-Hz DSP transmit audio filter, which is
> selected in the K3's configuration?  A friend just got his K3S and turning
> on the filter apparently prevented the AFSK transmission, which leads me to
> conclude the filter is designed for high tones.
>
> I use DXLab with WinWarbler as my general logger, which can use only MMTTY
> to transmit RTTY.  I understand that it's good to set MMTTY taps to 512 to
> transmit a narrow signal, so I'll do that.  I'll also consider transmitting
> AFSK with 2Tone when using N1MM+.
>
> Any other suggestions?
>
> Thanks very much.
>
> 73, Jim N7US
>
>
>
> _______________________________________________
> RTTY mailing list
> RTTY at contesting.com
> http://lists.contesting.com/mailman/listinfo/rtty
>