It might be a bit of an over-simplification to split oscillators in
those two camps, "fixed" and "agile". There are often many trade-offs in
performance that you have to deal with. Moreover if you are getting your
oscillators from eBay, or especially parts from China, you may also have
to assume that original factory specs are no longer valid.
This is one reason why the time nuts list is so preoccupied with making
accurate measurements of frequency standards. You only know what you
have if 1) you buy it new from a reputable company, or 2) when you buy
it cheap and measure it yourself with reputable test equipment, or 3)
you get it from a friend who has measured it for you.
If you're asking specifically about Rb, I think the data shows that hp
5065A has best performance, followed by PRS10, followed by all the cheap
telecom Rb. Sorry, I don't have plots or URL's handy at the moment to
support this with real data. My main take-away is to start with your
requirements, see which products / specs meet that, and if you're buying
dirt cheap surplus, make your own measurements to validate your
requirements.
/tvb
On 9/25/2019 3:45 PM, Taka Kamiya via time-nuts wrote:
This is a cross post from EEVBLOG. I'm hoping there is someone who's familiar
with this subject would help me out here.
I am hoping someone can help me understand this. I've seen similar discussions
take place both for GPSDO with Crystal Oscillators and Rubidium modules. It
appears there are two types of each.
1) fixed frequency type (less jitter)
2) frequency agile type (more jitter)
I've read frequency agile Rb modules (ones you can change output frequency) is
one kind of Rb (sa.22c and fe5650, etc), and there is another one that you
cannot change frequency. (ie. T-bolt, PRS10, etc). Words like phase noise and
PLL are thrown out often in discussions. I vaguely remember frequency agile
types are less suitable if ultimate in stability is needed such as multiplying
the output into GHz range. This discussion was about 10GHz transverter.
Is this because frequency agile type has the ultimate output from PLL (subject
to jitter) and fixed frequency type is from OCXO? If this is the case, why
frequency agile type even exist? It's not like it can be used as a VFO (on
radio).....
I'm sorry this is SO vague but that's the reason for this post. I need to
understand this. There was a wiki page on this, but it doesn't go into this
discussion deep enough.
Would someone help me gain knowledge in this?
---------------------------------------
(Mr.) Taka Kamiya
KB4EMF / ex JF2DKG
_______________________________________________
time-nuts mailing list [email protected]
To unsubscribe, go
tohttp://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
