I forgot to mention that if you go and do the math of programing the Si570 you will see that even the excel sheet provided by the company is giving valid register combinations for output frequency of 3.5MHz. This means if you divide it by 4 gives you a LO of ~0.86MHz. Now if you divide it by 8 since this is a functionality of the Softrock flipflops, then you can even go down to ~450KHz...
--- In [email protected], "Christos Nikolaou" <[EMAIL PROTECTED]> wrote: > > Hi Alan, > > I do use the Si570 from 1.8MHz up to 30MHz in my multiband Softrock setup. > I use it daily for my local 160m ragchew. > > My Si570 is the LVDS type with the addition of a FIN1002 to get a good > TTL signal for the 74AC74's. > > It is definitively a wonder chip compared to my AD9834,AD9851 and even > AD9954 that I already tested... > > 73 > Christos SV1EIA > > > --- In [email protected], "Alan" <g4zfq@> wrote: > > > > Has anyone confirmed if it is safe to run the Si570 out of spec? > > > > The reason I ask is that this morning I switched one that had been > running > > continuosly for several days to 7.2MHx output for 160m. > > It changed frequency, then did not respond. Removing power and > restarting it > > gave an output at 56.32MHz but it still did not respond to PIC or LPT > > control. I think it may have overheated, it seems OK now but I am > reluctant > > to test it for long at 7MHz out. > > This may just be coincidence but has Si Labs told us why the spec > stops at > > 10MHz when they all seem to work down to around 3.5MHz out? > > > > 73 Alan G4ZFQ > > >
