[time-nuts] motorola oncore descriptions

[Jack Hudler]

Ah I too wondered about the 10kHz output and wince it came.
One phase lock circuit being sold on eBay uses this by dividing it down to 1
PPS.
Perhaps he wanted to save one 74HC390. 

Still I wonder what the precision cost is?

Jack

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf
Of Didier Juges
Sent: Wednesday, December 13, 2006 7:09 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] motorola oncore descriptions

You have to be careful with the 10 kHz output. The output is only 
updated once per second (the 10,000 pulses in the 1 second period are 
equally spaced), so you still need the same filter as if you were using 
the 1 PPS output. I am not sure what the 10kHz output was intended to, 
but it's not that great of an advantage for phase locking a XO.

The only advantage I could see is if you are using a Jupiter to 
discipline a very lousy crystal oscillator, you could speed-up the lock 
by using a faster filter, then switch to a slower filter once lock is 
achieved. However, even though you will achieve lock faster, the 
precision will not be better (probably worse) than if you had a good 
OCXO to start with.

Didier KO4BB

Jason Rabel wrote:
>> Now, about the Rockwell Jupiter 8 boards...
>>
>> The TU30D140 is 5V powered (Antenna can be passive, 5V or 12V)
>> The TU30D160 is 3.3V powered (Antenna can be passive, 5V or 12V)
>>
>> Both boards have 10 KHz output. That's about it...
>>     
>
> Maybe I should clarify that one statement. I didn't mean they only have
> 10KHz outputs, I just meant that about it for your question. They also have
> a 1PPS output.
>
> With the 10KHz output you can build a poor man's GPS stabilized oscillator
> like here:
>
> http://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm
>
> I actually just got in the parts for to build one of these the other day,
> probably going to try and assemble today. I'm using a Millren 5MHz VC OCXO
> that I got a while back. The advantage to the above design is the simplicity
> (and cost).
>
>
> _______________________________________________
> time-nuts mailing list
> time-nuts at febo.com
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>
>   

_______________________________________________
time-nuts mailing list
time-nuts at febo.com
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts