[digitalradio] MFTTY Path Simulaitons
All, It's good to see the enthusiasm about MFTTY. It has a nifty GUI and its easy to use. A few have mentioned a lack of lack of sensitivity and that does seem to be the case. But I think it's safe to say that we don't always need to bring an elephant gun to a turkey shoot ; ). For what it's worth, and with all due respect to the author, I've tested MFTTY with an HF path simulator and it is less sensitive and less robust than say PSK31. On air tests seem to show that the mode performs well with low power under quiet conditions. Many thanks to Norbert and those like him who give us the opportunity to experiment and play with new modes. If it wasn't for them, we'd still be lugging those heavy RTTY machines into the shack ; ). Tony -K2MO
Re: [digitalradio] MFTTY Path Simulaitons
dear tony what speed did you use for the path simulation? when you take a slower mode the s7n will be higher cause the filter are narrower that´s why i asked about used speed for the test greetz dg9bfc sigi - Original Message - From: Tony To: digitalradio@yahoogroups.com Sent: Friday, January 16, 2009 1:49 AM Subject: [digitalradio] MFTTY Path Simulaitons All, It's good to see the enthusiasm about MFTTY. It has a nifty GUI and its easy to use. A few have mentioned a lack of lack of sensitivity and that does seem to be the case. But I think it's safe to say that we don't always need to bring an elephant gun to a turkey shoot ; ). For what it's worth, and with all due respect to the author, I've tested MFTTY with an HF path simulator and it is less sensitive and less robust than say PSK31. On air tests seem to show that the mode performs well with low power under quiet conditions. Many thanks to Norbert and those like him who give us the opportunity to experiment and play with new modes. If it wasn't for them, we'd still be lugging those heavy RTTY machines into the shack ; ). Tony -K2MO
Re: [digitalradio] MFTTY Path Simulaitons
Sigi, > what speed did you use for the path simulation? I used half-speed. I'll test the mode at different speeds and will post the results. Tony -K2MO
Re: [digitalradio] MFTTY Path Simulaitons
Hi Tony Have you done a path simulations test of the FEC version of the MFTTY mode? 73 de LA5VNA Steinar Tony wrote: > > All, > > It's good to see the enthusiasm about MFTTY. It has a nifty GUI and > its easy to use. A few have mentioned a lack of lack of sensitivity > and that does seem to be the case. But I think it's safe to say that > we don't always need to bring an elephant gun to a turkey shoot ; ). > > For what it's worth, and with all due respect to the author, I've > tested MFTTY with an HF path simulator and it is less sensitive and > less robust than say PSK31. On air tests seem to show that the mode > performs well with low power under quiet conditions. > > Many thanks to Norbert and those like him who give us the opportunity > to experiment and play with new modes. If it wasn't for them, we'd > still be lugging those heavy RTTY machines into the shack ; ). > > Tony -K2MO > > _
Re: [digitalradio] MFTTY Path Simulaitons
Steinar, I did test the FEC mode at half speed using the "canned" simulations from Moe Wheatley's PathSim and there doesn't appear to be any difference in performance. The half-speed mode seems to be quite a bit less sensitive than other keyboard modes and I would imagine throughput would suffer when signals are weak. The 1/4 and 1/8 speed modes have better sensitivity, but they are slow. It does appear to have better stability than say PSK31 when signals are severely distorted; at least that seems to be the case with polar path simulations (see below). Tony - K2MO Minimum Sensitivity MFTTY (1/2 Speed).. -6db MFSK16...-14db Olivia 16/500-13db PSK31..-10db Simulation: High Latitude Disturbed Path delay: 7ms Frequency spread: 30Hz SNR: -3db (weak signal) Mode Throughput MFTTY (1/2 Speed). <10% MFSK16...75% Olivia 16/500..100% PSK31.no copy SNR: +10db (moderate signal) Mode Throughput MFTTY (1/2 Speed). <10% PSK31.no copy Simulation: Mid-Latitude Disturbed Path delay: 2ms Frequency spread: 1Hz SNR: -8db SNR (weak signal) Mode Throughput MFTTY (1/2 Speed). <25% MFSK16.100% Olivia 16/500..100% PSK31...70% SNR: +10db SNR (moderate signal) Mode Throughput MFTTY (1/2 Speed)... 80% MFSK16.100% Olivia 16/500..100% PSK31..90% Simulation: Low-Latitude Disturbed Path Delay: 6ms Frequency Spread: 10Hz SNR: -8db SNR (weak signal) Mode Throughput MFTTY (1/2 Speed)... 25% MFSK16.100% Olivia 16/500..100% PSK31.no copy SNR: +10db SNR (moderate signal) Mode Throughput MFTTY (1/2 Speed)... 80% MFSK16.100% Olivia 16/500..100% PSK31.no copy > Have you done a path simulations test of the FEC version of the MFTTY mode? > 73 de > LA5VNA Steinar
Re: [digitalradio] MFTTY Path Simulaitons
Great! Thanks Tony 73 de la5vna Steinar Tony wrote: > > Steinar, > > I did test the FEC mode at half speed using the "canned" simulations > from Moe Wheatley's PathSim and there doesn't appear to be any > difference in performance. > > The half-speed mode s eems to be quite a bit less sensitive than other > keyboard modes and I would imagine throughput would suffer when > signals are weak. The 1/4 and 1/8 speed modes have better sensitivity, > but they are slow. > > It does appear to have better stability than say PSK31 when signals > are severely distorted; at least that seems to be the case with polar > path simulations (see below). > > Tony - K2MO > > > > > Minimum Sensitivity > > MFTTY (1/2 Speed).. . ... -6db > MFSK16.. . . . ..-14db > Olivia 16/500.. . . -13db > PSK31... . . . -10db > > > Simulation: High Latitude Disturbed > > Path delay: 7ms > > Frequency spread: 30Hz > > *SNR: -3db (weak signal)* > > Mode Throughput > > MFTTY (1/2 Speed).. . . . <10% > MFSK16.. . . . . .75% > Olivia 16/500.. . . . .100% > PSK31... . . . . ..no copy > > > > *SNR: +10db (moderate signal)* > > Mode Throughput > > MFTTY (1/2 Speed).. . . . <10% > PSK31... . . . . ..no copy > > > > > > Simulation: Mid-Latitude Disturbed > > Path delay: 2ms > > Frequency spread: 1Hz > > *SNR: -8db SNR (weak signal)* > > Mode Throughput > > MFTTY (1/2 Speed).. . . . <25% > MFSK16.. . . . . ...100% > Olivia 16/500.. . . . .100% > PSK31... . . . . 70% > > > > *SNR: +10db SNR (moderate signal)* > > Mode Throughput > > MFTTY (1/2 Speed).. . . ... 80% > MFSK16.. . . . . ...100% > Olivia 16/500.. . . . .100% > PSK31... . . . . ...90% > > > > Simulation: Low-Latitude Disturbed > > Path Delay: 6ms > > Frequency Spread: 10Hz > > *SNR: -8db SNR (weak signal)* > > Mode Throughput > > MFTTY (1/2 Speed).. . . ... 25% > MFSK16.. . . . . ...100% > Olivia 16/500.. . . . .100% > PSK31... . . . . ..no copy > > > * SNR: +10db SNR (moderate signal) * > > Mode Throughput > > MFTTY (1/2 Speed).. . . ... 80% > MFSK16.. . . . . ...100% > Olivia 16/500.. . . . .100% > PSK31... . . . . ..no copy > >
