Henk ten Pierick wrote: > On Apr 25, 2007, at 23:38, Dave Brown wrote: > > >> Henk >> Do any of the spurious signals show on the SA with a search antenna >> (located in your lab environment)connected instead of the PRS10? >> DaveB >> > > > No, they are not. I can see spurious if and only if the PRS10 is > powered. When I open the PRS10 and search with a loop antenna, then I > see the whole spectrum up to 600MHz. Most of the power comes from the > board with the micro which runs at 10MHz. I expect that there is a > parasitic coupling of this micro 10MHz to the PRS10 output. This can > explain why the spurious level increases with frequency to higher > than the spectrum analyzer noise level at say 500MHz. The micro slew > rate can explain why it decreases again into the noise above 700MHz. > The spurious is only there if the micro runs. It is not clear to me > why I can see this spurious and other PRS10 owners can not. May be a > different run or version of the PRS10. My PRS10 has serial 5099. > > Henk > > _______________________________________________ > time-nuts mailing list > time-nuts@febo.com > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > Henk
If indeed the micro is the source of the spurious frequencies that other PRS10's do not exhibit, then either you've got an unusually fast micro or there is something wrong/different in the micro supply decoupling and/or EMI filtering. The PCB layout could differ or different or even extra components may have been used in the other PRS10's. Bruce _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
