|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
73.229.29.71
In Reply to: RE: Possible to split a 10Mhz clock output? posted by eduardoo on December 15, 2016 at 19:42:19
As knewton already mentioned, you might get by with a simple BNC T adapter depending on the loads and how they are terminated at the receiving ends, and the cable lengths. Another option is to use something called a distribution amplifier.
Personally, I'm not convinced that the 'accuracy' of a Rubidium clock is of any benefit in a home audio setup. The output of a Rubidium clock actually comes off an ovenized voltage controlled crystal oscillator that is locked to the hyperfine transition state of the Rubidium atom (~6.834 GHz). The phase noise of the crystal oscillator is probably more important than the clock's absolute long term accuracy.I worked for a company called Efratom in the 1980s on crystal oscillators, Rubidium clocks, and hydrogen masers in a past life. And I stayed at a Holiday Inn Express a few weeks ago. ;-)
Didn't we talk about this almost 4 years ago? What 'custom made' Rubidium clock do you have?
Edits: 12/17/16Follow Ups:
Yes, that was me.
Got one made with an fe5680a with a nice linear PS in a decent box for a few hundred dollars. As said, despite the likely limitations, it does seem to sound better with it in the system, so I just left it there.
Very cool! But how do you know that it's output is precisely 10.00000000 MHz as shown on the HP frequency counter?
Is the reference clock in your HP frequency counter more accurate than your Rubidium oscillator? ;-)
We used a reference Rubidium oscillator that was calibrated and traceable to the National Bureau of Standards (now called NIST). The signal from the reference Rb oscillator was input into a Tracor frequency difference meter and compared against new Rb oscillators that we produced. The reference Rb oscillator would be sent back to a calibration lab periodically to ensure that it's accuracy was certified and traceable to NIST.
It's interesting to note that the freq diff meter needle would swing in one direction and then the other as the crystal in the Rb oscillator would be swept in each direction (with an error voltage applied to a varactor diode which changes it's junction capacitance which would of course alter the frequency of a tuned circuit) until the physics package warmed up and disciplined the crystal output and locked it to the hyperfine transition state of the Rb atom.
Here's an old Tracor Frequency Difference meter similar to the one I used to use. Fun stuff back in the day. Enjoy your Rb oscillator.
That frequency counter belongs to the guy who made the thing for me. I actually asked him the same question. He said that his counter had been calibrated with some reference facility (can't remember the name now, but it sounded credible to me when I heard it), so I guess I'll just have faith in it. :P
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: