Paul and Bob are my valuable mentors, and I trust their opinion. I do have an old working Cs but my go-to are GPSDO. For most part, it's more than sufficient. I also have ex-telecom Rb. There aren't too many things one of them can't do, except for measuring themselves. In my lab, the "lab standard" is GPSDO and backup is Rb. At a hobby level, one of the big issue (at least to me) is power consumption, and the heat they generate. My lab gets significantly warm. Plus, instant availability of GPSDO and Rb (because they are always on) is hard to beat. To save Cs, I only turn on mine when needed, then wait for 2 days. To be honest, I'd love to have an HP5071A with warranty. But it's far beyond affordable range for me. Also, a "standard" I can't trust isn't a standard. I am not good enough to properly care for Cs and I don't have good enough measuring system. It takes a lot to keep Cs happy and usable in many ways. Signed, on laziest ham.
--------------------------------------- (Mr.) Taka Kamiya KB4EMF / ex JF2DKG On Saturday, March 14, 2020, 12:14:43 PM EDT, paul swed <paulsw...@gmail.com> wrote: I will chime in here also. It is indeed great to say you have a cesium. HP 5061s are just good fun to play with. It teaches you that as much as you think you know you actually don't. But they do honestly take care and feeding especially in the tail-end market that i can afford. So to Bobs comment if you want a good reference for time-nuttery the GPSDO is a really effortless way to go. Hard to say if RB or Xtal is better it depends on what you might get at a flea market. But there is a lot to be said for turn it on and be happy. I actually run a GPSD-TCXO as a instant on sort of right there for my ham stuff. Power consumption sub 10 Watts. Then flip to a HP3801 or any number of alternates including Cesium for serious stuff like D-PSK-R development. Signed one lazy ham. Regards Paul WB8TSL On Sat, Mar 14, 2020 at 8:31 AM Bob kb8tq <kb...@n1k.org> wrote: > Hi > > Backing off a bit, as long as GPS is doing it’s part ( or your GNSS system > of > choice …) an OCXO based setup may do as well as / better than your typical > “almost dead” used Cs standard. > > It is very easy to find a used Cs with a dead tube. It is quite hard to > find one > with a tube that is fully up to original specs / runs for years. Finding > replacement > tubes is ( and always has been) a very involved process. There are way > more > used / dead tubes out there than used / working. > > Buying a new tube is in the “forget about it” price range. There also is > no practical > way to rebuild one. You can do this or that trick to maybe get a bit more > time out > of this or that tube … but maybe not. > > Thus the pair of dead 5061’s sitting in the basement. > > Bob > > > On Mar 14, 2020, at 12:06 AM, Peter Membrey <pe...@membrey.hk> wrote: > > > > Hi guys, > > > > Potentially a bit of a loaded topic, but I'm really curious as to what > the consensus is on this. For the research I've been doing over the past > few years, I've been predominantly using an SRS FS-725 (which uses the > PRS-10) disciplined by a Microsemi S650 (with the Rb option, though it > never went into holdover). > > > > Modern Caesium references are expensive compared to the FS-725, but now > and then more classic Caesium references become available such as the HP > 5061A. These still aren't cheap (actually, not far off a brand new PRS-10) > so I was wondering how do they generally compare with a modern Rb? > > > > If I have a PRS-10 that's being disciplined by a good GPS source, would > I see any benefit if I replaced the PRS-10 with an HP5061A (particularly in > terms of stability)? > > > > Thanks in advance! > > > > Kind Regards, > > > > > > Peter Membrey > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.