Hello Vojtech and Tony, > has very low crest factor, so the effective transmitted power will be
An example, with a 100 watts HF transceiver, keeping linear: * you can transmit 10 watts of MT63, * you can transmit 76 watts of Contestia. 73 Patrick ----- Original Message ----- From: "Vojtech Bubnik" <[EMAIL PROTECTED]> To: <digitalradio@yahoogroups.com> Sent: Saturday, October 11, 2008 4:08 PM Subject: [digitalradio] Re: Contestia 1K vs MT63? > 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* >> > > > > ------------------------------------ > > Announce your digital presence via our Interactive Sked Page at > http://www.obriensweb.com/sked > > 30M digital activity at http://www.projectsandparts.com/30m > > Recommended software : DM780, Multipsk, FLDIGI, Winwarbler ,MMVARI. > Yahoo! Groups Links > > > > >
