Hi Tony. Even though the simulation results look promising for MT63, they do not take real HAM SSB transceiver into account. SSB PA of an average HAM TRX is usually not very linear and the many carriers of MT63 will mix with each other, which will show up as an added noise. Also MT63 has very low crest factor, so the effective transmitted power will be much lower than of Contestia if you do not overdrive the TX. I bet you will be better of to use Contestia on the air using let's say an average 100W YaeComWood.
73, Vojtech --- In digitalradio@yahoogroups.com, Tony <[EMAIL PROTECTED]> wrote: > > All, > > I was playing with the Contestia mode in an attempt to duplicate the wpm rate of MT63. I configured Contestia with 16 tones and a bandwidth of 1K. The sensitivity of the two seemed to be the same and the wpm rate appeared to be close. > > I then tested both modes with the HF path simulator dialed-in for selective fading with the SNR set a few db above the minimum decode threshold. As you can see below, print was better with MT63. > > The deep fades caused garbled characters with Contestia and it would appear the better copy with MT63 is a result of the redundancy built into the mode. > > I'm not sure if that's an accurate assessment as to why there is a difference, but it would seem so. Wonder if anyone can shed some light on this. > > Tony, K2MO > > > Path Simulation : Selective Fading > SNR : -3db / -6db > > > Contestia 1K / 16 tone > > SNR -3db > > THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG > THE QUICK BROWN FOS OVER TH- >G > THE BROWN FOXMPS OVER THE LAZY DOG > THE QUICRO,N FOX JUMPS OVELAZY DOG > > SNR -6db > > TE QUCK BROW FOX JUMPS OVER THE LAZY DOG > THE QUG2NOWNS YVER THOEG > THE BROWN FO#UBR OVER TE LAZY DOG > THE QUIC^_^N FOX JUMPS OVELAZY DOG > > > MT63 1K > > SNR -3db > > *DE K2MO* > THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG > THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG > THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG > THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG > *EOT* > > SNR -6db > > *DE K2M > TH QUICK &AOWN FOX JUOP; OVrR THE LAZY ROG > THE Q%ICK BROWN FOX JUMPS OVER THE LAZY DOG > THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG > THE QUICK BROWNFOX JUMPS OVER THE LAZY DOG > *EOT* >
