I’ve just replaced the SR620 oxco option 01 with a Morion, by simply adding a 7812 to the 15 v heater feed. Locks well with either gpsdo or cesium external source. Don’t forget to turn on the external option and set the frequency for 5 or 10 MHz. It took about 5 days for the Morion to reasonably settle down. I agree about the Rb, has to be set with Gpsdo anyway, and I’ve already had 2 of them go South.
Prescalers from RFBay. Don > On Nov 27, 2014, at 4:25 PM, Brooke Clarke <[email protected]> wrote: > > Hi David: > > For me the key benefit of the SR620 is the 16 digit display. That implies a > lot of digits in the reference (although not all 16 of them) so I always use > an external reference. > > When I turn the PRS-10 upside down the crystal changes frequency and the Rb > corrects the crystal, see: > http://www.prc68.com/I/PRS10.shtml#Accel > http://www.prc68.com/I/Images/FC_ROT.jpg > > Mail_Attachment -- > Have Fun, > > Brooke Clarke > http://www.PRC68.com > http://www.end2partygovernment.com/2012Issues.html > http://www.prc68.com/I/DietNutrition.html > Dr. David Kirkby (Kirkby Microwave Ltd) wrote: >> On 27 November 2014 at 22:15, Brooke Clarke <[email protected]> wrote: >>> Hi David: >> Hi Brooke >> >>> If you look just to the right of the SR620 you will see a separate box that >>> contains the PRS10. >> Ah, I missed that!!! >> >> I was thinking it fitted inside the SR620, but obviously not. >> >>> The PRS10 can work as either a Rb GPSDO or as a time stamping device. For >>> the SR620 any GPSDO would make a good external reference. >> It would have been nice to have a better reference inside, as >> sometimes I move equipment around, and don't always want to take more >> than necessary, so having a better reference inside would have been a >> nice thing, but I see it is not what I thought. >> >> This unit I purchased has the option 01, the ovenized VCXO, but of >> course that is not going to have the long-term stability of a Rb >> source. >> >> I see one of the SR625 add-ons on eBay, >> >> http://www.ebay.com/itm/STANFORD-RESEARCH-SYSTEMS-SR625-2GHz-PRESCALER-/281486714451?pt=US_Marine_Aircraft_Radios&hash=item4189ea6653 >> >> but it does not look in good condition, so I'm not paying $700 for it. >> >> Dave >> _______________________________________________ >> 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. > _______________________________________________ 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.
