[time-nuts] Darn you people....

[paul swed]

I built up the ZAZ GPSDO and like Bert have very very good performance.
Whats crazy interesting is the oven I am using is a Lucent one from the cel
towers.
All of the stuff combined the thing draws very low power. Its been a while
but I want to say 7 watts compared to may of the GPSDOs in the 30-50 watt
range.
Just another dimension to the timenuttieness "The green effect".
Regards
Paul.
WB8TSL

On Tue, May 3, 2011 at 4:42 PM, Bert, VE2ZAZ <ve2zaz at yahoo.ca> wrote:

> Luis,
>
> You said: <<Furthermore the frequency counting resolution is 16 seconds, so
> the ZAZ gpsdo won't lock better than 0.0625Hz.>>
>
>
> On my GPSDO design, a single 16-second frequency sample does have a
> resolution of 0.0625Hz. But the FLL firmware does averaging over as many
> samples as you want before adjusting the OCXO. So I don't agree with your
> statement that the ZAZ gpsdo won't lock better than 0.0625Hz. In fact, I
> have never seen my design go worse than 1x10E-9. It usually sit below
> 5x10E-10. This concurs with the many reports I got from other users.
>
>
> Please elaborate.
>
> Thanks,
>
> Bert, VE2ZAZ
>
>
>
>
> Message: 3
> >Date: Tue, 03 May 2011 18:14:30 +0100
> >From: Luis Cupido <cupido at mail.ua.pt>
> >To: Discussion of precise time and frequency measurement
> >    <time-nuts at febo.com>
> >Subject: Re: [time-nuts] Darn you people....
> >Message-ID: <4DC037F6.5090206 at mail.ua.pt>
> >Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> >
> >Bob,
> >
> >You must be aware that the VE2ZAZ GPSDO does not lock the 10MHz phase to
> >the phase of the 1pps. It is a frequency counter which uses the
> >frequency error to correct the 10MHz VCXO. So it is a frequency locked
> >loop FLL.
> >
> >By definition on a PLL you will have the phase error being used to
> >compensate the 10MHz VCXO
> >On a FLL a frequency error is required to compensate the 10MHzVCXO
> >
> >While having a permanent very very slow OCXO trend (drift or aging)
> >a PLL(order 2) will exhibit a constant phase error while the frequency
> >is right. With an FLL it will have a constant frequency error.
> >
> >Furthermore the frequency counting resolution is 16 seconds, so
> >the ZAZ gpsdo won't lock better than 0.0625Hz.
> >A PLL scheme, thunderbolt, the old Brook Shera's, the 10KHz James
> >Miller's, or my reflock (I or II) will get you always on the ballpark.
> >
> >
> >This PLL/FLL aspect is a subtle difference that has absolutely no
> >expression whatsoever for radio-ham applications both TX and RX on HF to
> >microwaves etc. application to which it was targeted and serve very well.
> >
> >
> >But you will surely start to see these small aspects when you step into
> >the next level of timenutness !!!
> >Apparently you have both feet there... looking at sub Hz you're infected
> >that's a fact ;-)
> >
> >
> >Luis Cupido.
> >ct1dmk.
> >
> >
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