Hello Joe and Bill, Thanks for the reminding. I have read the manual and have completely forgotten about the signal strength range differences.
The recent improvements in the JT65 decoder is just remarkable. There are times that two or more signals are interlaced with one another and the decoder decodes all signals. Really impressive. 73, Edson PY2SDR --- - We humans have the capability to do amazing things if we work together. - Nós seres humanos temos a capacidade de fazer coisas incríveis se trabalharmos juntos. On Tue, Dec 22, 2015 at 3:03 PM, Joe Taylor <[email protected]> wrote: > Hi Edson, > > Signal strengths reported by JT65 have always maxed out at -1 dB. > (Indeed, they start compressing and are significantly nonlinear above > -10 dB or so.) The reason is historical: JT65 was developed for EME, > where the SNR in 2500 Hz BW is essentially never greater than 0. As > originally defined, the JT65 protocol supports signal reports from -1 to > -30 dB. > > JT9 uses (almost) the same source encoding to compress user messages > into 72 bits. But it was developed for use st MF and HF, where signals > can be much stronger. By co-opting some code ranges otherwise used for > grid squares near the North or South poles, JT9 supports signal reports > from -50 to +49 dB. > > You'll find some relevant information here in the User Guide: > > http://www.physics.princeton.edu/pulsar/K1JT/wsjtx-doc/wsjtx-main-1.7.0-devel.html#_standard_exchange > : > > "JT65 reports are constrained to lie in the range –30 to –1 dB, and > values are significantly compressed above about -10 dB. JT9 supports the > extended range –50 to +49 dB and assigns more reliable numbers to > relatively strong signals." > > -- Joe, K1JT > > On 12/22/2015 11:54 AM, Edson W. R. Pereira wrote: > > Hello everyone, > > > > I have been monitoring using wsjt-x v1.7.0 r6286 and am noticing that the > > JT65 decoder is not showing signal strengths stronger than -1 dB. Even > with > > very strong signals the decoder shows -1 dB. The JT9 decoder does show > > signal strengths above 0 dB. > > > > Has anyone noticed this? > > > > 73 and season's greetings, > > > > Edson PY2SDR > > > > --- > > - We humans have the capability to do amazing things if we work together. > > - Nós seres humanos temos a capacidade de fazer coisas incríveis se > > trabalharmos juntos. > > > > > > > > > > > ------------------------------------------------------------------------------ > > > > > > > > _______________________________________________ > > wsjt-devel mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/wsjt-devel > > > ------------------------------------------------------------------------------ > _______________________________________________ > wsjt-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/wsjt-devel >
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