[A-DX] {dxld} VOA Radiogram, Mar 28-29: faster and faster text

Di Mär 31 20:49:33 CEST 2015

Am 27.03.2015 um 22:53 schrieb  [dxld]:
> ......
> We will try two of the new 8PSK modes 
> <http://www.w1hkj.com/FldigiHelp-3.22/psk_page.html> with forward 
> error correction (FEC). These are available in 3.22.06. The FEC built 
> into 8PSK125F and 8PSK250F might help these modes survive the rigors 
> of shortwave, despite their fast speed.
> This weekend’s program (program 104) will transmit the same 724-word 
> news story about social media in Africa in five different modes, each 
> increasing in speed, until MFSK32 resumes to close the show …
>  .......
> It is likely that decoding errors will be seen as the modes increase 
> in speed. Nevertheless, please stay tuned until the closing 
> announcements and image in MFSK32.


  2:53 MFSK32 (120 wpm)*          no errors, not a problem
12:18 MFSK64 (250 wpm)*          no errors, not a problem
18:05 8PSK125F (317 wpm)         slower than MFSK128 and yet significant 
problems, unusable for intercontinental shortwave
20:55 MFSK128 (480 wpm)*         no errors, not a problem,    very 
robust faster mode
25:17 8PSK250F (635 wpm)         error rate high, mode not worth discussing


+ WRMI-datacast  9955 kHz