[time-nuts] FE-5680B Rubidium and DDS

Bryan _ bpl521 at outlook.com
Fri Sep 25 21:45:13 EDT 2015


There is information on this thread on how you can tap into the unit at various points to get 20 and 60Mhz. Other owners have used a divider to bring it to the 10Mhz frequency desired. I have one of these units and haven't gone around to dividing it down. I purchased mine from Ebay and the seller notes that this particular version will output 10Mhz for a second or two and then disappear. I suspect you have the same version, maybe even the same seller, so the operation of these particular units appears to be normal. Mine will lock so I know it's working.
http://www.eevblog.com/forum/testgear/fe-5680b-1pps-to-10mhz/msg556800/#msg556800
I as well wish there was a quick way of converting it back to 10Mhz. I am sure it can be done, just not sure how or where to look <g>

-=Bryan=-

> From: kb8tq at n1k.org
> Date: Fri, 25 Sep 2015 17:45:08 -0400
> To: time-nuts at febo.com
> Subject: Re: [time-nuts] FE-5680B Rubidium and DDS
> 
> Hi
> 
> There is no dump of the firmware. The problem you are most likely 
> having is not firmware related.
> 
> If the VCXO i the unit drifts to far it needs to be re-tuned. Until this is done
> the device simply sits in a “search for lock” loop forever and ever.
> 
> Simple way to do it:
> 
> Monitor the VCXO and bump the trimmer until the frequency goes above the intended
> target (10 x N MHz depending on your monitor point) by at least 0.15 ppm. The sweep is
> slow enough that a counter running at a 0.1 second gate will easily show you what’s going on.
> 
> Of course it can be other things. All of them are a bit more involved to fix.  
> 
> Bob
> 
> > On Sep 25, 2015, at 11:34 AM, Clint Jay <cjaysharp at gmail.com> wrote:
> > 
> > I've recently purchased one of the PPS Only FE Rubidium standards from eBay
> > and, like many others I suspect, haven't been able to get a stable output
> > frequency that lasts longer than a few seconds from the module.
> > 
> > It appears that the 10MHz source vanishes after a few seconds but this is
> > controlled by firmware.
> > 
> > Which leads to my question, there is a dump of the firmware from the
> > FE-5680, has anyone tried to reprogram one?
> > -- 
> > Clint.
> > 
> > *No trees were harmed in the sending of this mail. However, a large number
> > of electrons were greatly inconvenienced.*
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
 		 	   		  


More information about the time-nuts mailing list