Email: kc9sgv AT gmail dott com On Tue, Mar 20, 2012 at 11:16 AM, Bernard Dekok <kc9sgv@xxxxxxxxx> wrote: > Hi John, > > As a daily user of ACARS in the aeronautical VHF band, I have a certain > expectancy of what should be achieved with data over VHF. > > Please email me a copy too, and I will test via my two VHF stations into > dummy loads. > > Best 73, > And please keep up your excellent work. > > Bernie, > KC9SGV > Chicago. > > > On Tue, Mar 20, 2012 at 10:37 AM, Karel Fassotte <karel.fassotte@xxxxxxxxx > > wrote: > >> Hello John I was realy waiting for this possibility. >> Ik will find some stations overhere to do the testing. >> HR-PE2KFA/HC1AKP >> 73 Karel >> >> >> 2012/3/20 John Douyere <vk2eta@xxxxxxxxx> >> >>> Hello Pskmail operators, >>> >>> I am ready to send, off list, a few copies of a special alpha Fldigi >>> with new modes for testing. >>> >>> This first batch of new modes is targeted specifically at the fast FM >>> (normally VHF/UHF) links as they require a clean bandwidth of up to 2400Hz >>> and will suffer badly in the standard SSB passband. So please do not use >>> the wider ones on HF. >>> >>> Also note that their baud rate is above the Amateur HF bands Baud limit >>> in the USA for all but two of the PSK modes. >>> >>> Note that I am separately preparing a USA HF Amateur version with only >>> modes below 300Baud and one for HF outside of the USA with faster Baud >>> rates. >>> >>> In this version, the top speed provides 3200 words per minute or 19200 >>> characters per minute (using the Fldigi definition). In tests I got a 17124 >>> characters text file to be downloaded in just under one minute in >>> compressed format, including repeats and ARQ overheads, so I think this >>> could be interesting. >>> >>> Unfortunately as this point I have not been able to get my existing >>> version of the Windows cross-compile to work, so it is for Linux only until >>> I get this to work. >>> >>> Instead of creating new mode designations I have simply re-mapped the >>> existing list of modes we use for Pskmail into a new set. >>> >>> That has the advantage of making the tests simple by just using the >>> temporary Fldigi program on both sides without any change in Pskmail. All >>> features will be the same including the configurable mode list. The only >>> drawback is that the timeouts are still related to slower modes so will be >>> in some cases way too long (like 30 seconds for the PSK63 -> PSK1000R >>> mode). But the objective is to review the modes not the Pskmail performance >>> itself. >>> >>> Of course these modes are usable with FLARQ of the NBEMS suite. >>> >>> I expect to have about 5 to 6 new modes from the list below retained in >>> the final "FM implementation". They will then get their new designation and >>> RSIDs. >>> >>> All these final modes will also be integrated in the Pskmail V2 >>> (integrated Java modems) and in the Android version of Pskmail (they >>> already run on my HTC Desire). >>> >>> I have arranged these test modes in a similar order of robustness as the >>> ones they replace. >>> >>> Here is the mapping: >>> >>> Original mode New Temporary Mode >>> Speed Bandwidth (-3dB) >>> >>> PSK63 1 Carrier PSK1000R >>> 880WPM 1000Hz >>> >>> PSK125 1 Carrier PSK1000 >>> 1600WPM 1000Hz >>> >>> PSK250 6 Carriers PSK250 >>> 2400WPM 2000Hz >>> >>> PSK500 2 Carriers PSK1000 >>> 3200WPM 2400Hz >>> >>> PSK125R 2 Carriers PSK500 >>> 1600WPM 1200Hz >>> >>> PSK250R 2 Carriers PSK1000R >>> 1760WPM 2400Hz >>> >>> PSK500R 14 Carriers PSK125 >>> 1540WPM 2400Hz >>> >>> I have also re-mapped the MFSK and THOR modes the following way: >>> >>> Original mode New Temporary Mode >>> Speed Bandwidth (-3dB) >>> >>> MFSK16 MFSK64 >>> 240WPM 960Hz >>> >>> MFSK32 MFSK128 >>> 480WPM 1920Hz >>> >>> THOR8 THOR44-Double spaced >>> 156WPM 1600Hz >>> >>> THOR11 THOR44 >>> 156WPM 800Hz >>> >>> THOR22 THOR88 >>> 312WPM 1600Hz >>> >>> The MFSK64 mode is the same as the current one but that way we get to >>> have an RSID associated with it for our tests (the MFSK16 RSID). >>> >>> The double spaced THOR44 is targeted mostly at NVIS conditions (4 dBs >>> better than the single spaced one) so I don't think it will provide a >>> benefit for FM paths. >>> >>> The MFSK/THOR modes should be of most interest for poor FM links (where >>> the noise is high). >>> >>> In some Pskmail tests I did over VHF, the THOR modes were virtually as >>> sensitive in FM as in SSB (I think Skip Teller - KH6TY - has an article >>> in QST about this). >>> >>> Due to the required bandwidth I would suggest a waterfall audio centre >>> frequency of 1750 or 1800Hz for FM transmissions. >>> >>> These preliminary modes specifications are published in the Pskmail wiki >>> to respect the regulation. See http://pskmail.wikispaces.com/newmodes >>> >>> I have not made the source code available yet as it is preliminary but >>> of course it will be released under GPL in due course and I hope integrated >>> in the mainstream Fldigi. >>> >>> Could you please feedback the following information which is of most >>> interest to me: >>> >>> 1. Any issue with the software itself. >>> >>> 2. CPU load of the different modes on your computer (approximate average >>> and peak value - use the "top" command in a terminal). >>> >>> 3. The modes that Pskmail mostly settle on, the ones it has problems >>> with and what were the conditions of the test (signal strength, quieting >>> etc...). >>> >>> 4. More advanced: when frames are damaged, does it tend to be in >>> the beginning, the middle or at the end? >>> >>> From my Pathsim tests and initial field trials I would bet on the >>> following set: PSK1000R, 2 x PSK1000R and 2 x PSK1000 as a useful mode list >>> for FM transmissions, plus a couple of FSK modes, but let's see what you >>> find out in the field. >>> >>> To get a copy, email me off list at <my callsign> at gmail dot com >>> >>> Have fun, >>> >>> All the best, >>> >>> 73, John >>> >> >> >