And started down the dark path you have. You will not have to wait long before you completely succumb to the dark side.
Jim Palfreyman 2009/12/28 Bob Camp <[email protected]>: > Hi > > Your budget is going to make things tough. > > A Thunderbolt needs a triple supply (+12, -12, and +5) to operate. It also > needs a GPS antenna of some sort. > > The Rubidiums all need a supply and a heat sink. Some of them like the FRS-A > need unusual connectors. > > They all need to be operated continuously to get the best accuracy. That > makes powering them with a shared lab supply impractical. > > The Thunderbolt is accurate as a stand alone device because it uses GPS. The > rubidiums are all fairly accurate by design, but they would need to be > calibrated against something else to be as accurate as the Thunderbolt. > > Simple look at it: > > If you need ~ 3x10-9 accuracy, then the rubidiums are all fine. > > If you need < 2 x10-10 accuracy, then the Thunderbolt is your only choice. > > In between those two limits, it depends on a lot of details like how long > between calibrations, environment (like temperature), and sources of > calibration. Even at the limits I've mentioned, what you are calibrating > might impact the choice. > > If you have a spare triple output supply already, Then the Thunderbolt is > inside your budget. If you do not have a supply, you probably can pick up the > pieces on individual auctions with some luck and patience. If you go with a > rubidium, look for a dealer who will include the connectors for the device. > > One last point: The Thunderbolt *probably* will run for a very long time. The > rubidiums may also run for a long time, or they may die 5 or 10 years from > now due to lamp wear out. > > Lots to think about. > > Bob > > > On Dec 27, 2009, at 4:12 PM, Giuseppe Marullo wrote: > >> Hi all, >> just subscribed, I would like a quick advice on a 10MHz reference for >> calibrating my instruments and for fun. In particular, I would like to know >> if you could give me advice on EFRATOM FRS-A,FRS-C, DATUM LPRO-101, >> Thunderbolt and such. >> >> I would prefer a GPSDO (like the Thunderbolt), but budget is very tight >> (about 100EUR), so I am searching old surplus stuff on Ebay. >> >> Some examples: >> >> http://cgi.ebay.com/Thunderbolt-PRECISION-GPS-10mhz-FREQUENCY-TIME-Standard_W0QQitemZ270504461779QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3efb5285d3 >> >> http://cgi.ebay.com/EFRATOM-10MHZ-LPRO-101-Rubidium-Frequency-Standard_W0QQitemZ270504461780QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3efb5285d4 >> >> Any caveat, anything I should ask to the seller? Minimal fw version for the >> Thunderbolt (2.2 is okay)? >> >> Thanks in advance, >> >> Giuseppe >> >> PS: I am in Italy >> >> _______________________________________________ >> 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.
