[time-nuts] New PLOTTER version / HP5065 Frequency processing part II

[Magnus Danielson]

From: "Ulrich Bangert" <df6jb at ulrich-bangert.de>
Subject: [time-nuts] New PLOTTER version / HP5065 Frequency processing part II
Date: Sat, 11 Nov 2006 18:03:50 +0100
Message-ID: <000001c705b3$62eca7f0$03b2fea9 at athlon>

> Hi folks,

Hi Ulrich,

> Now comes the strange fact: HP's 5065 is equipped with a tuneable
> synthesizer to generate the microwave frequency from the OCXO. HP states
> that this tuneable synthesizer can be used to generate a number of
> different 'time scales' as some of you also have pointed at. I
> understand this very well!
> 
> But the STRANGE thing is that HP uses DIFFERENT synthesizer settings
> albeit the intended purpose of the tuning ALSO to generate THE SAME time
> scale with two different physics packages. 
> 
> That is what we found on two different physics packages:
> 
> Physics Package 1      C-Field 7.21       Synth. 8619  -   5.31498914
> Mhz
>  
> Physics Package 2      C-Field 8.24       Synth. 8397  -   5.31503431
> Mhz
> 
> Please note that the two synthesizer setting are different by MORE THAN
> 45 Hz. This is just one example, other physics packages may perhaps even
> be more apart. We have seen above that there is reason to believe that
> all environmental influences are smaller than +/-7 Hz. So where comes
> this 45 Hz difference from?

Not sure this is going to help you, but:

With the C-field trimming you may tune the resonance frequency and the
frequency synthesizer may be set accordingly to acheive the same frequency.
You should be able to adjust your synthesizer and then trim your C-field to
acheive TAI/UTC pseudo-synchronisity. The different old rubidium
implementations use different resonance synthesis step up relations and thus
require different C-field strengths to acheive correct output frequency.

Naturally toss in the frequency pulling correction for that individual physical
package.

If you have two HP 5065 rubidiums alongside, then set one of them up the same
as the other, and then you should be able to trim it up on the C-field for
propper frequency again.

Cheers,
Magnus