Hi Brett, Please refer to my comments in your email below. Best 73s, John On Wed, Jun 30, 2010 at 3:27 PM, <pskmail@xxxxxxxxx> wrote: > On 30/Jun/2010 00:32 Steven Heimann <steven@xxxxxxxxxxx> wrote .. >> Hi John >> >> It would be nice if the modes used by PSKMail were configurable rather >> than being hard coded in. In cases like this where FM will be used the >> server could limit the modes to ones useful for FM. Also, as the >> channel bandwidth is fixed modes wider the 500Hz could be selected which >> could increase speed. >> >> Just a thought. I think there are two parts to your question: A. As mentioned in my email to Steven, I struggle with the benefits on HF, but again I may be missing something. B. For FM applications there would be a case for a separate list of modes, which again could be hard coded if we take the simple coding route. Alternatively, as you mentioned, we could limit the current list to the appropriate modes for that application, but in reality the system should be quite capable of adjusting itself as it continuously measured the signal quality both ways and makes decisions to change modes based on this. I haven't performed new tests using FM since we developed the adaptative mode feature, so if you were to do some tests we would be glad to hear back from you. With particular interest in the way the mode adaptation works in that case. >> >> Regards >> Steven > > Greeting- > > Is there no way to tell the server to use a wider bandwidth & higher speed > mode? As mentioned above and in previous email the issue I have is that there are no higher speed mode available at present in Fldigi that we don't already use. For information, we tried PSK1000 but the results were not conclusive. > I would think one could get an easy 9600 baud in a standard FM channel. This would be an issue of mode available in Fldigi rather than Pskmail per say. The issue that become apparent quickly when pushing the speed envelop towards the theoretical limit is that while if is possible to have a lab version of a protocol working at higher throughput that what we have now, the issue is when you get in the field, the hardware variations (PC sound card, radio, interfaces) is so large that it is easy to end up with a system that is not reliable and therefore does not get used or distracts from the objective. For example getting 9600 bauds on an FM channel required very good TX deviation accuracy and from what I have read is not a plug and play exercise. The other example was the PSK1000 test we did. In the current mode list we use you can have uncalibrated sound cards (off by thousands of PPMs) with non linear interfaces and far from linear rigs (in terms of frequency response) and still get through. So like life, this is full of compromises. But again we are open to new ideas. > > 73 > > -Brett > wa3yre > >