First of all, thanks to John and Magnus for inputs and links, makes a very good start!
On 9/18/10, Magnus Danielson <[email protected]> wrote: > On 09/18/2010 09:48 AM, francesco messineo wrote: >> Hello all, >> >> sorry for the OT, but the electronic expertise of the group is too good >> :-) >> >> I'm looking for ideas and directions (articles and so on) to realize >> very good phase noise xtal oscillator, in the range 20-50 MHz for high >> performance frequency conversion. I would like to understand what >> circuits can be realized (not requiring too much professional and >> modern equipment, test eq. from the 70s-80s is ok) and what is the >> contribution of the active oscillator device, the xtal itself and the >> following buffers. >> Another idea that came on my mind was using digital oscillator (square >> wave, cmos) and then filtering for sine output, if this makes sense >> for a low PN point of view. >> Is there any way to measure the close-in PN of oscillators with an >> amateur setup? > > First of all I think you need to quantify what you mean by "high > performance frequency conversion" and what stability measures you are > seeking as there are many degrees of excessiveness to attempt, and many > of them may be well beyond what you need. Remember, we are time-nuts... :) > Ok, let's say as good as practically and economically feasible for "single" prototype and homebuilder. I already chosed not to use a Si570 because I really need only few (2-4) fixed frequencies and I'm assuming that carefully made xtal oscillators can beat the Si570 phase noise performance. The conversion is obviously for a receiver, not for the classic HF bands, but for the lower VHF amateur bands (50-70 MHz) where IMD3 performance of the receiver has to be the best possible, as these bands are used for TV and radio broadcasts in many nearby countries around here. Of course a very good frontend BPF, amplifier and mixer are needed, but these are less of a problem for me to chose (and are simpler to evaluate with "standard" test equipment too). Unfortunately I know very few low-VHF-nuts and very few of them (if any) realize their setup performance are so far distant from what can be achieved nowadays. Thanks again Frank IZ8DWF _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
