> Rick wrote: > Wouldn't the variability be due to not knowing the conditions we operate > when on the air vs. the controlled and known conditions during the test?
Yes, that's the problem Rick. It's difficult to mimic on-air conditions with a simulator and I doubt there's one capable of duplicating the variability of the real ionosphere. My gut feeling is that the mode prints closer to the noise floor than my pathsim sensitivity tests indicate. There's always some degree of ionospheric distortion on a real HF channel and seeing the mode print at what appeared to be a lower on-air signal-to-noise ratio vs. the simulators direct-path tests (no HF channel distortion) was impressive. This is all speculation on my part so we'll have to test some more. It probably won't prove anything, but it might be interesting to compare on-air recordings to the minimum signal-to-noise performance obtained from the simulator. Tony -K2MO --- Original Message ----- From: "Rick W" <mrf...@frontiernet.net> To: <digitalradio@yahoogroups.com> Sent: Tuesday, June 02, 2009 5:34 PM Subject: Re: [digitalradio] PSK-ARQ versus ALE-400 > Wouldn't the variability be due to not knowing the conditions we operate > when on the air vs. the controlled and known conditions during the test? > > There are times that a given mode just can not work in a real world > environment, even though you might be able to hear the signal just find. > It just can not print well, and yet another mode that can handle the > conditions of Doppler and ISI multipath can work FB. > > 73, > > Rick, KV9U > > > > > Tony wrote: >> >> >> Jose, >> >> > maybe Tony could devise some measurements to compare them. >> >> I'm not sure why, but on-air tests with ALE-400 seem to be a bit >> more robust than my path simulations indicate. Need to test this mode >> more. >> >> Tony -K2MO >> > >
