[time-nuts] Morion MV89A Repair

[Neville Michie]

Hi,
I have two of Morion MV89A, one is prominently marked (RoHS 5).
I assume that means lead-less solder. Pure tin solder is much more  
prone to
crystallised joints which break later.
Are these the dodgy units ?


cheers, Neville Michie





On 26/02/2012, at 11:02 AM, John Miles wrote:

>
>> -----Original Message-----
>> From: time-nuts-bounces at febo.com [mailto:time-nuts-
>> bounces at febo.com] On Behalf Of Bob Camp
>> Sent: Saturday, February 25, 2012 2:55 PM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] Morion MV89A Repair
>>
>> Hi
>>
>> The spectrum you show in the middle is the correct one. It shows  
>> the 10
> MHz
>> output and the sub-harmonics related to the 5 MHz crystal  
>> oscillator. The
>> other two are a bit broken. One appears to have a stage  
>> oscillating. The
>> other is more interesting. It has a stage oscillating that is  
>> injection
> locked to
>> the 5 MHz crystal oscillator. I suspect more than one capacitor  
>> went bad
> in
>> these OCXO's. Somebody may have sold Morion a bad reel of bypass  
>> caps.
>>
>> Bob
>
> Interesting.  The MV89As are very stable, but they have a lot of AM  
> noise
> and they don't meet their PN specs (about -150 dBc/Hz at 10 kHz  
> rather than
> -155).  I've tested a few and they all look the same in that respect.
> Sounds like replacing all of the SMT caps may be a good move.
>
> -- john
>
>
> _______________________________________________
> 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.