Hi Larry, Thank you for the feedback. Keep us informed of the results please. 73, John On 21/03/2012 10:12 PM, "Larry Levesque" <ka1vgm@xxxxxxxxx> wrote: > Thanks for the tips. > > It is running fine on my Ubuntu 10.04 machines. > > I will be doing some testing over VHF simplex in the next week or so. > > I just sent a 30k file in under 2 minutes. Wow!! > > > > On Wed, Mar 21, 2012 at 09:59:00PM +1100, John Douyere wrote: > > Some extra information regarding the usage of the new modes in FM. > > > > In my test I have noticed that it is easy to overload the TX audio and > > start loosing decoding accuracy on the other side. > > > > Since the ALC level is not related to the audio level in FM, the > indicator > > I use is the Modulation level (FT-8x7 series). > > > > As an example I found that having the modulation indication at about 1/3 > of > > the maximum for a single carrier PSK is about right, giving a reasonable > > audio level but no visible distortion. > > > > The multi-carrier modes can be a trap since the average level is lower > than > > a single PSK carrier modulation but the peaks are the same. So it sound > > lower but the level must not be increased to compensate, otherwise the > > peaks get truncated and the decoding suffer too. > > > > In SSB, the multi carrier PSK modulations will result in an average power > > well below that of the single carrier PSK, but again we should not try to > > compensate for it. > > > > Under these modulations, if you push the TX audio level ALC too high you > > actually may well be getting only 20% of the max RIG power at the output, > > with the ALC way up. > > > > Hope this helps, > > > > 73, John > > -- > Larry Levesque > www.surrycomputerservices.com > >