HI For anything short of microwave multiplication, the 15 MHz output of the Z3810/11/12 is likely to be “good enough”. The 60 KHz noise hump that may be from the power brick isn’t going to make it through a PLL going to VHF, so the only benefit of pulling the brick would be some sort of SDR running directly off of 15 MHz. A crystal bandpass filter at 15 MHz could be made (or found) in that case. The brick probably does a better job rejecting the 50/60 Hz stuff you would get into with a direct supply setup.
So let’s see … Nyquist at 7.5 MHz. 1/2 band at 3.75 MHz. You could have a real good radio from maybe 4 MHz on down to DC. That might be interesting, but it’s probably not going to get a lot more people buying these up to do it. Bob > On Nov 18, 2014, at 9:22 AM, Bert Kehren via time-nuts <time-nuts@febo.com> > wrote: > > I would not mess with the power management of the unit, HP did know what > they where doing. Any clean up I would move off the unit if you want to stay > with the same OCXO you have one in the second unit. > As to phase noise before time nuts issues took up all my time low noise > signal generators where my main focus and will be again. I know of no high > quality Sig. Gen that does not include a 100 MHz XO and in some cases > higher > frequency SAW units. And that has been going on for as long as I can > remember and I am 72. > One subject no one has touched on is thermal control. I do not know but > suspect forced air cooling that would explain why all connectors on the > front. > From comments by some members we are looking at 20 W. I will include a fan > along with temperature control. > Bert Kehren > > > In a message dated 11/18/2014 12:21:32 A.M. Eastern Standard Time, > don_he...@gmx.de writes: > > Hello List, > > having not looked at the spectra yet as I am confined to mobile phone > instead of PC often, I had the idea to marry those two well-known > devices to get a nice clean reference oscillator. I remember the > spectrum of the FEI as not so nice, and the MTI sounds better. > > > My understanding is yet that I would need to emulate the REF1 unit, > basically need to look up the "lonely REF" tweak with the bridges in J5, > maybe fake valid GPS datagrams with a microcontroller and turn the 1PPS > pulse from the FEI into that 2 PPSes expected. > > Replacing the Lucent Power Brick with a linear supply and bridging the > tripler to get 5 MHz out might be tweaks to increase the output spectrum > further. This was discussed before, I think, i have to look it up too. > > (I wonder if the REF0 acts up after complete removal of the source REF1 > or keep on doing holdover which would be a nice way to take a good > frequency standard to a ham radio repeater side) > > BR > > Hendrik > > _______________________________________________ > 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.