It's fairly clean - there is a bit of harmonic distortion since its being generated from a 10MHz square wave via a simple LC filter but it seems otherwuse quite nice. The RF architecture of these new units is quite different from the old ones and the VCXO now runs at 60MHz this is divided down in a Xilimx PLD and the output comes from that - the RF for the snap diode drive is generated by mixing the 60MHz with the output of a DDS chip and it seems that the FM needed to interrogate the Rb cell is applied in this loop rather than directly to the VCXO.
Overall, I think the output is quite a bit nicer than the old units. On Nov 11, 2011 6:32 AM, "WB6BNQ" <wb6...@cox.net> wrote: > > Peter, > > Is the 10 MHz output a clean sinewave or does it look kind of trashy ? > > thanks, > > Bill....WB6BNQ > > > Peter Bell wrote: > > > Assuming it's the same as the units I have (two labels, with "FEI P/N > > 217400-30352-1" on the upper label and two barcodes on the lower > > label) then the +5V supply runs all the logic in the unit. There are > > no special power sequencing requirements, but you need both supplies > > for the unit to operate. The current drain on the 5V line is fairly > > low - about 90mA - the 15V will pull about 2A when the unit is cold > > and then drops to 500-600mA once everything is warmed up. Pin 3 is > > the lock indicator - driven low when locked. The output (10MHz sine) > > is present on pin 6, and appears immediately after power up - although > > the frequency is not accurate until the lock pin is asserted. > > > > The 4 digit prefix on the lower barcode is a date code - so "S/N > > 0416-77234" would indicate a unit made in week 16 of 2004. > > > > Regards, > > > > Pete Bell > > > > On Fri, Nov 11, 2011 at 12:30 AM, <ewkeh...@aol.com> wrote: > > > I did purchase one of the "New" FE-5680A Rb's. Looking at packaging and > > > the housing it does look new. I have not powered it up because of +5 Volt on > > > pin 4. Does any one know its purpose and is there a power up sequence. Any > > > help will be appreciated. > > > Bert Kehren Miami > > > _______________________________________________ > > > time-nuts mailing list -- time-nuts@febo.com > > > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > and follow the instructions there. > > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.