Hi Norbert. I do not want to discourage you from your experiments, but I would like to point out, that there are already two tone chat modes designed for amateur use on HF, namely Throb and ThrobX. DTMF as well as ThrobX encode each single character into two simultaneous tones. Throb has a single exception, idle character is encoded as single tone. DTMF does not shape amplitude, Throb/ThrobX does. DTMF is much wider than Throb or ThrobX.
I believe DTMF was designed for cheap inexact tone decoders and not fully harmonic encoders and transmission paths, the tones are picked so their third intermix product is not exactly aligned with other DTMF tones. If used on HF, one does not want the IMD product fall outside of the useful signal. On telephone line it does not matter and some nonlinearity may be even useful to boost SNR. On HF I don't believe big tone spacing will bring much benefit when compared with ThrobX. 73, Vojtech OK1IAK --- In digitalradio@yahoogroups.com, "Norbert Pieper" <polar_elect...@...> wrote: > > Hello Siggi and Group, > > i'm very glad to see that you were able to use MFTTy with some > success. > So far i have learned that "tune finder" is needed. > And a Hlepfile in a more readable format? > > I will add a graphical, FFT-Based, "tune finder" This might take a > week or two. I will let you know when done. > > Please send me your additional suggestions, i will collect and > considder them as my little available time allows... step by step. > > 73 > 55 > de > Norbert > > > > --- In digitalradio@yahoogroups.com, "Siegfried Jackstien" > <siegfried.jackstien@> wrote: > > > > dear norbert > > thanks for the "second edition" of your software > > i will try it out on my system and can send you my comments about > > best 73´s de dg9bfc > > sigi > > ----- Original Message ----- > > From: Norbert Pieper > > To: digitalradio@yahoogroups.com > > Sent: Saturday, December 13, 2008 3:15 PM > > Subject: [digitalradio] Re: mftty > > > > > > Hello to the Group!! > > > > I'm new here and have some goddies... > > > > I freshly released an update of MF Tele Type V 2.0.088 > > http://www.polar-electric.com/MFTT/ > > > > And yes it is possible to run MFTT under Vista > > Instructions: > > Launch program directly from it's Program folder location for > > example > > "c:\Program Files\HamRadioSoftware\MFTeleType\MFteletype.exe" > > > > In the properties table one must set: > > > > XP Servicepack2 ( right click on the MFteletype.exe file to > access > > the properties tab and select XP Service pack 2) this step need > be > > done only one time. > > > > Execute as Administrator (each time one runs the program, it is > > necessary to right click the .exe file and select to run it as > > Administrator. ) > > > > Whish you lots of fun with MFTT! > > Any feedback is welcome. > > > > 73 > > 55 > > de > > Norbert > > >
