[time-nuts] TPLL linearity and other questions

[Tom Van Baak]

David,

The 10811 linearity may not be that good rail to rail, but how linear is yours over the narrow EFC range you use during a stability measurement? I would expect it to be very good over any given interval of a few or tens of mV.

/tvb

----- Original Message ----- 
From: "David Hooke" <dhooke at gmail.com>
To: "Discussion of precise time and frequency measurement" <public-time-nuts-JSkTLETqlTM at plane.gmane.org>
Sent: Monday, July 22, 2013 5:23 AM
Subject: [time-nuts] TPLL linearity and other questions


> 
> 
> Hi All,
> 
> I've built a measurement PLL along the lines of W. Riley's and Warrens's 
> designs. It's working, but I have a hole in my understanding of them. 
> The transfer function of the OCXO (10811-60159 in my case) is decidedly 
> non-linear, implying that that the voltage output is also not 
> proportional to frequency. Where does this non-linearity get corrected 
> before analysis in either Warren's or Bill's systems?
> 
> Also, without access to a 5062C as a noise source as some lucky folk do, 
> what test modulation patterns could I use to verify and calibrate the 
> gadget? I have an HP8662A, 3325A, 33120A and 8648C which I can rig 
> together to generate various phase or frequency modulations. Simple FSK 
> gives the expected square wave output (which is where I noticed the OCXO 
> non-linearity). What other tests would you recommend?
> 
> Also, I have 24bit, 192k sound cards which work down to around 1Hz. Are 
> there any analysis packages I should look at to explore PN output, or is 
> spectrum lab the best best?
> 
> Thanks from a beginner.
> 
> david