Hello Tony, >Thanks for that information. Is it safe to say that the SNR difference between >Contestia and Olivia stays the same as long as the tone >and bandwidth >configurations are the same? Yes it is always about 1.5 dB as long as the tone and bandwidth configurations are the same.
>Can you also tell us what the approximate peak-to-average output is for MT63? >I understand it's near 10db? I measured also 10 dB (Pmean/Ppeak: 0.1 for MT63 versus Pmean/Ppeak: 0.76 for Olivia and "clones" as Contestia). 73 Patrick ----- Original Message ----- From: Tony To: [email protected] Sent: Thursday, March 26, 2009 12:03 AM Subject: Re: [digitalradio] Contestia / MT63 Skeds pse Patrick, Thanks for that information. Is it safe to say that the SNR difference between Contestia and Olivia stays the same as long as the tone and bandwidth configurations are the same? Can you also tell us what the approximate peak-to-average output is for MT63? I understand it's near 10db? Tony -K2MO ----- Original Message ----- From: "Patrick Lindecker" <[email protected]> To: <[email protected]> Sent: Wednesday, March 25, 2009 6:27 PM Subject: Re: [digitalradio] Contestia / MT63 Skeds pse > Hello to all, > > Here is what I noted on my help file. In fact I found Contestia is a very good compromise (a small loss in S/N compared to Olivia with a double speed, but without small letters). > > However, I don't like RTTYM due to the fact that you have the same problem as in RTTY: you can swich randomly from characters to figures or reversely. That's a problem. > > 73 > Patrick > SUMMARY OF THE CHARACTERISTICS OF CONTESTIA AND RTTYM COMPARED TO OLIVIA > > * CONTESTIA is a bit less sensitive than Olivia (+1.5 dB on minimum S/N). It is a also a bit less robust (due to a smaller block size) but it is twice more rapid (with a reduce set of characters). > > This mode is an excellent chat mode (because sensitive and rapid). > > * RTTYM is a less sensitive than Olivia (+ 3 dB on minimum S/N). It is also less robust (due to a small block size and due to the RTTY problem of random shift from letters to figures or reversely, on an error) but it is almost four times more rapid (with the RTTY set of characters). > > This mode is interesting for very quick QSO. > > > > ----- Original Message ----- > From: kh6ty > To: [email protected] > Sent: Wednesday, March 25, 2009 10:27 PM > Subject: Re: [digitalradio] Contestia / MT63 Skeds pse > > > Tony, > > Glad you are doing this! I have been thinking about using Contestia for MARS in conjunction with MT63 for messaging. > > Unfortunately, I have one net to call tonight and one to checkin to, so will have to wait to see the results of your tests. > > Unless Conestia is especially good in other parameters, MFSK16 still holds a 1.5 dB edge in minimum S/N, and seems to work very well in heavy static, so it may turn out to be the best overall, but let's see. > > I used MultiPSk for my comparisons. > > Anxious to see what you find out! > > 73, Skip KH6TY > http://kh6ty.home.comcast.net > > > ----- Original Message ----- > From: Tony > To: [email protected] > Sent: Wednesday, March 25, 2009 4:14 PM > Subject: [digitalradio] Contestia / MT63 Skeds pse > > > > All, > > Would like to run a few tests with Contestia (16/1K) and MT63 (1K) this evening. The goal is to see if sensitivity simulations compare well with on-air testing. Contestia should have an advantage since the peak-to-average output is much better. Not sure about it's QRM resistance. > > The MT63 mode is somewhat faster in terms of characters-per-minute, but it also has quite a bit of latency that adds to the total TX/RX turn around time. > > I tested both using a 100 word Pangram and found that MT63-1K (long interleave) took 50 seconds to finish the text and 61 seconds to complete. Contestia-16/1K took 64 seconds. The 8/1K Constestia mode took 43 seconds. > > Should be interesting to see how these modes compare. Not exactly lighting speed and not much call for this other than those who prefer high-speed chatting, but I think it's useful information nonetheless. I'll be QRV this evening - March 25/26. Skeds welcome.... > > Tony -K2MO > > > > > > > >
