[time-nuts] FE5680A square-wave output

[bob grant]

I'm not that fond of the way in which 10MHz is made available on a DB9.
But there's a vacant site for an AC161 on the FE5680 PCB to perform a /6 
operation from the 60MHz crystal. To good an opportunity to miss up....

Here is some pics of the mod.

http://s1090.photobucket.com/albums/i370/bobgrant1/TimeNutz/?albumview=slideshow

There is scant decoupling here, and it shows up as 6 blips in 
high/low signal levels whenever there is a signal transition.

I needed to add a tantalum, X7R, C0G and a small piece of FR4 with Cu
tape.
The output is on a RG178 SMA pigtail. 

Series termination worked best with 47R and 330R in parallel delivering
a reasonably nice 5V signal.


Earlier you may recall the "Why a 10MHz sinewave?" thread, and for those 
there are component sites for 390p and 1uH which make a wide bandpass
filter.


Have fun










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