[A-DX] Shortwave Radiogram, 17-19 March

[Roger]

Am 16.03.2018 um 20:57 schrieb kd9xb:
> Shortwave Radiogram this weekend is all in MFSK32.
> It includes the simultaneous transmission of text (centered on 1500 
> Hz) and an image (on 2200 Hz).
> Details and schedule:
> http://swradiogram.net/post/171935841637/shortwave-radiogram-17-18-march-2018-text-and


The reception was damn good again. It was difficult to see a difference. 
Only with a zoom you can realize a bit more noise in the 2200Hz picture.

http://www.rhci-online.net/radiogram/SW_Radiogram_2018-03-17.htm#2200Hz


However, in the spectrum display, it becomes clear: The second 
concurrent image track drains modulation-power from the 1500 Hz-main track:

http://www.rhci-online.net/radiogram/SW_Radiogram_2018-03-17.htm#SWRG


In case of difficult propagation conditions a significant reduction of 
the decoding quality is to be expected, when using a two-tracked 
encoding, so I think.
This is the usual balancing act between signal ruggedness and 
information density.


roger