[pskmail] Re: Alpha Testers for fast modes
- From: Karel Fassotte <karel.fassotte@xxxxxxxxx>
- To: pskmail@xxxxxxxxxxxxx
- Date: Tue, 20 Mar 2012 10:37:10 -0500
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
>
Other related posts:
