OK Tom Some things for me to look at. The Zeeman freq method never worked for me. I tried high and low drive and several generators that are very accurate. But will take a look. Thanks
On Sat, Dec 6, 2014 at 1:18 PM, Tom Van Baak <[email protected]> wrote: > > Now if the device was on one of those side peaks what would that make > the offset at 5 MHz be?. > > I think something like 1 Khz divided by 9192631770. I am sure 5 MHz > comes into the calculation. > > Pretty small. But may guess thats what I see. Its 44ns slow over 27 > minutes as of yesterday. > > The systems been on 4 days. > > Paul, > > 40 kHz / 9192 MHz is 4e-6, so you're obviously not locked to one of the 6 > wrong peaks. > > 1 kHz / 9192 MHz is 1e-7, or 100 ns per second, so I don't think you're > locked to one of the 2 side peaks either. A 1e-7 error translates to 0.5 Hz > out of 5 MHz. > > 44 ns / 27 minutes time drift = 2.7e-11 frequency offset. Maybe all you > need to do is adjust the C-field dial. As a quick test measure the 5061A > output frequency at min C-field and max C-field to get an idea of your > tuning range. HP used two different ranges on the 5061A. Or measure at each > turn of the dial, as I did here: > http://www.leapsecond.com/pages/hp-5065a-cfield/ > > If you want, perform the Zeeman calibration as described in the 5061A > manual. It says "an error of 1% in the Zeeman frequency causes an error of > 3.6 parts in 10^12 in the 5 MHz output". > > /tvb > > ----- Original Message ----- > From: "Tom Van Baak" <[email protected]> > To: "Discussion of precise time and frequency measurement" < > [email protected]> > Sent: Saturday, December 06, 2014 9:04 AM > Subject: Re: [time-nuts] HP 5061Cs reference question > > > Paul, > > There are 7 peaks total, about 40 kHz apart (on my 5061A). If you're > talking about just the central peak, there are two smaller peaks on either > side, about 1 kHz apart. The exact value depends on internal magnetic > field, which is specific to each beam tube design. > > For some measurements of all the peaks, have a look at: > http://leapsecond.com/pages/cspeak/ > > You can play with the C-field in addition to playing with peaks: > http://leapsecond.com/images/cfield.gif (578 x 4610 pixels) > > For more details search the archives for the word Zeeman. For example: > https://www.febo.com/pipermail/time-nuts/2005-April/018171.html > > A nice description from hp how a cesium beam standard works: > http://leapsecond.com/museum/hp5062c/theory.htm > > /tvb > > > ----- Original Message ----- > From: "paul swed" <[email protected]> > To: "Time-nuts" <[email protected]> > Sent: Saturday, December 06, 2014 6:11 AM > Subject: [time-nuts] HP 5061Cs reference question > > > >I have a curious question that really applies to all Cs references. > > Its possible to set them on to the wrong peak. > > Typically in the literature it will speak to at least 3 peaks and you > want > > to select the highest central peak. > > However if you select the wrong peak, how much would the output frequency > > be off? > > I had read a tech note for the airforce that seems to indicate its pretty > > easy to get on to the wrong peak. > > Regards > > Paul > > WB8TSL > > > _______________________________________________ > 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. > _______________________________________________ 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.
