hello Rex, from what I have seen the lowest noise is available on the Z3801 with 10811. I also have a Z3815 with E1938A oscillator, but the 3801 is much less noisy and more stable. Don't have a 3816 or 3805 to test against.
Keep in mind that there is a large performance variation from unit to unit as can be seen in TVB's Z3801A performance plots.. there are a good number of Z3801As modified to be 58503As on Ebay now. Got one from Yinxh some time ago, and that unit took over one year to fully settle down! Now I am consistently getting xE-013 ADEV from 0.1s to a couple 100s out of it. PN is excellent on that unit too. bye, Said Sent From iPhone On Jun 3, 2012, at 2:21, Rex <[email protected]> wrote: > Said, > > Thanks for the info and congrats on the stats from the Jackson Labs stuff. > > You mentioned the older HP Z3801. I wonder if you (or others) happen to have > comparison numbers on the Z3816A with the MTI 260 oscillator or the Z3805 > with (I think) the same oscillator. I thought I heard the MTI 260 might be > slightly better than the 10811 but can't recall if anyone here actually made > measurements, > > Not to say that any of the HP Z---- stuff is seen for sale often these days. > But I have one of each of the above mentioned. > > Guess it may be close to the *time* where I should take the *time* to build > or set up a system where I could get trustworthy measurements of these > *timing* quality things myself. I keep reading but never seem to find the > time to actually do it. > > -Rex > > > On 6/3/2012 1:46 AM, [email protected] wrote: >> Jerry, Chris, >> >> it's all relative, while the Lpro may be a good Rb standard, it's phase >> noise is not that good really. You list: >> >> -96dBc/Hz @ 10Hz, -138dBc/Hz @ 100Hz, -152dBc/Hz @ 1KHz offsets >> >> For the Lpro. The new Jackson Labs Technologies LN CSAC GPSDO with SC-cut >> phase noise and ADEV filter achieves the following: >> >> -138dBc/Hz @ 10Hz, -148dBc/Hz @ 100Hz, -152dBc/Hz @ 1KHz offsets. >> >> At 1Hz offset we see -105dBc/Hz and better on that unit. >> >> The FEI-5680A Rubidium that we discussed here some time ago has a much >> worse phase noise plot of course, because the 10MHz is generated digitally >> through a DDS, not a 10MHz crystal oscillator.. >> >> It all depends on your requirements, and your budget.. I think the Z3801A >> (or it's brother the 58503A) is still one of the lowest phase noise and >> best ADEV GPSDO on the surplus market if you get a typical unit, and if you >> can >> locate one. >> >> bye, >> Said >> >> From: Jerry Mulchin<[email protected]_ (mailto:[email protected])> >> Date: June 2, 2012 16:44:14 PDT >> To: Discussion of precise time and frequency measurement >> <[email protected]_ (mailto:[email protected])> >> Subject: Re: [time-nuts] GPS and Rubidium frequency standards and noise >> question (newbie). >> Reply-To: Discussion of precise time and frequency measurement >> <[email protected]_ (mailto:[email protected])> >> >> >> >> >> >> Chris, >> >> To answer your question regarding using a Rubidium standard as a frequency >> reference >> for your Transverters. >> >> GPS really has nothing to do the main requirement regarding Phase Noise >> and your >> Transceivers. But the 10MHz oscillator inside the Rubidium standard is the >> item >> that will be the Phase Noise problem if you get the wrong Rubidium >> standard. There >> are cheap Rubidiums and there are good Rubidium standards to consider. >> >> An LPRO-101 is actually a very good Rubidium standard, and exhibits Phase >> Noise >> values of -96dBc/Hz @ 10Hz, -138dBc/Hz @ 100Hz, -152dBc/Hz @ 1KHz offsets >> from carrier. This is what I use for my 10GHz Transverter reference, but I >> don't lock it >> to GPS when in the field. LPRO-101's can be gotten pretty reasonably. >> >> Locking the LPRO-101 to a GPS will require more support circuitry, and >> most of the >> folks on this list can help you with that. >> >> Also, Thunderbolt GPS disciplined units are nice, but I do not know the >> Phase Noise >> numbers of a typical Thunderbolt unit. Others here probably know the >> answer to that. >> >> The important thing to remember is you don't what to use 10MHz oscillators >> that have >> poor Phase Noise performance as it will effect your weak signal capability >> if you use >> a poor Phase Noise oscillator. >> >> Jerry >> >> At 03:05 PM 6/2/2012, you wrote: >> >> If you want a frequency reference. There is nothing better than GPS. In >> >> >> fact it you bought a Rubidium you would still need the GPS so you could >> >> >> calibrate its frequency. >> >> >> >> >> >> Some GPSes might be noisy but then you can lock a good double oven crystal >> >> >> oscillator to it and have what they call a "GPS disciplined crystal >> >> >> oscillator or "GPSDO". >> >> >> >> >> >> >> >> >> >> >> >> On Sat, Jun 2, 2012 at 2:57 PM, Chris Wilson<[email protected]_ >> (mailto:[email protected])> wrote: >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> I am looking to get a frequency standard for my amateur radio shack, >> >> >> >> >> initially for verifying test gear readings, but later as a standard >> >> >> >> >> to lock receiver and transmitter oscillators to. I was going to buy >> >> >> >> >> a GPS frequency standard but a friend warned me these may have noise >> >> >> >> >> issues when I come to use it with an oscillator in RX / TX >> >> >> >> >> applications. It's not something I had considered, so what's the >> >> >> >> >> score here please? Should I not buy a GPS standard? Thanks. Any >> >> >> >> >> links to known safe suitable purchase sources from personal >> >> >> >> >> experience welcome, either here or by PM or e-mail. I am in the UK. >> >> >> >> >> >> >> >> >> >> -- >> >> >> >> >> Best regards, >> >> >> >> >> Chris Wilson _mailto:[email protected]_ (mailto:[email protected]) >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> _______________________________________________ >> >> >> >> >> time-nuts mailing list -- [email protected]_ (mailto:[email protected]) >> >> >> >> >> To unsubscribe, go to >> >> >> >> >> _https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts_ >> (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.
