On 04/06/2013 02:22 AM, EB4APL wrote:
Thank you for the info, I used to attach a magnetic mount surface
thermometer to my FRS-C to check its operating temperature after
installing it in a box. I think it is time to power it up and after some
days check it against the GPS.
Ehm. Rubidiums is tweaked by magnetic field adjustments, and you have
my-metal shields to shield of ambient fields as they go in the wrong
direction typically, change, etc.
Use the C-field EFC input and not magnets to tweak it...
Please keep magnets away!
Cheers,
Magnus
Regards,
Ignacio EB4APL
On 05/04/2013 20:59, Bob Quenelle wrote:
I found the cause of the 4 mHz frequency jump. I have an LPRO-101, an
FE-5680, power supplies and a Motorola M12T GPS board in a surplus case.
When I put the case away to work on another project I piled the hockey
puck antenna and lead in the case and it happened to land on the
FE-5680. I noticed the antenna stuck firmly to the FE-5680 case when I
got the project back out. I found I could get a 6 mHz (0.6 ppb) shift
comparing the frequency with residual magnetism from the magnet stuck on
the FE-5680 case to the frequency after demagnetizing the FE-5680 case.
Unintentional C field adjustment. Dope slap, live and learn.
Bob
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