If the S/N ratios are measuring above the noise, the numbers indicate a very good link. As I have found out the hard way, when we tested SCAMP, it was not easy to even maintain 10 dB above noise. I am not clear on the amount of data you are sending as it appeared to be used more as a chat mode? Or did you send large files too?
Did the path drop out rather suddenly? The S/N levels seemed to be holding up quite well. If you had switched to Olivia, MFSK16, etc., do you think you could have continued communicating? The 8PSK ALE modes are the same or very similar waveforms to what is used in RFSM2400 and the advantage of PC-ALE is that it now supports CAT PTT switching which is something I expect in a modern digital program. When I use the term ALE, I am mostly referring to the various modulation schemes as one thing. I personally have minimal interest in the Link Establishment part of ALE as I don't see this as being used much except for some longer distance alerting on HF for sudden emergencies. What I do see more useful is that the modulation schemes are available as a more open standard and can compete with Pactor modes. The fastest modes in RFSM are not as fast as the fastest modes in "ALE" since they can go about double that speed but do require ISB I think and that will not be used on HF amateur radio bands. Again, maybe we need to change the terminology to the appropriate MIL-STD or STANAG such as we do with Multipsk calling the slow speed 8FSK125 waveform 141A? 73, Rick, KV9U Les Keppie wrote: > Hi Rick > Yes relative S/N reports are given for each paket - but what > they relate to is any ones guess and since I have no really good test > equipment that would do this cant really answer - but yes good data can > still be passed with signal levels just above 0db according to what > we see - and the higher the S/N R the faster speeds can be acheived > as you should see from the email I sent it is adaptive in speed to the > S/N R report it gets back from the receiving station > If you study the logs I sent you can see it changing speed to adapt to > the changing S/N R reports it gets > It keeps a record of all exchanges it makes (except the actual data) > in four seperate logs > > No I havent tried the faster Ale modes - whilst I have PC-Ale running > on my computer I do not fancy it all that much > Ale may well be good at finding openings at various times on various > frequencies but mostly they are too poor and too short to pass much > useful data anyway - and to get decent thruput of data using a > comparable waveform it probably requires similar S/N R figures as RFSM8000 > > Using Amateur bandwith- (ie. the nonstandard mode in RFSM8000) the > maximum capable speed is 6666 bits per second which is quite a bit > faster than that of Ale > > I will attach all four logs to cover this mornings test transfers > between VK2DSG and TEST4 - > You can now work out if you think it works > > The tests were done on 7196 usb over a distance of 400 klm > TEST4 was using 200 watts and I using 100 watts pep > > Band faded out at end with no transfer possible > Regards > Les > >
