[time-nuts] FMT on October 13

[Hal Murray]

>> Did mounting it on a block of foam help?

> That is a rather bad solution. You want much softer material to react
> to quicker things, such as silicon rubber. Also, that would only be a
> 12 dB/Oct solution. You would really like a few more poles there. The
> trick is to add weight to the calculation. So you want a very soft
> material, holding a thick block (lead) and from this base suspend the
> oscillator through a soft material again. Now you have a 24 dB/Oct
> solution. The trouble you now will have is that the wires will be
> another shock/vibration transport mechanism. They would need to be
> connected to the middle-frame such that outer forces hit the middle
> weigth and not directly on the sensitive part. They would need to be
> soft and arranged is such a way that they do not push or pull the
> inner end, but is allowed to flex alot. 

Yes, but inserting a chunk of foam is a lot easier than finding a block of 
lead.  It's likely to be good enough.  (Make that "good enough for most 
application.  This is time-nuts.  Nothing is good-enough that somebody won't 
suggest something better/nuttier.  :)

Packing bubbles might work too.  I'm thinking of the sheets of bubble wrap 
that are fun to snap rather than the foam peanuts that get all over the place 
and are really nasty if you have a slight static charge.

Does anybody have any data on the sensitivity of a crystal oscillator vs 
frequency of mechanical shock/vibration?  Does it scale with amplitude or 
acceleration or ???





-- 
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