[time-nuts] FMT on October 13

[Magnus Danielson]

From: Hal Murray <hmurray at megapathdsl.net>
Subject: Re: [time-nuts] FMT on October 13
Date: Tue, 25 Sep 2007 14:23:21 -0700
Message-ID: <20070925212322.607D3BE29 at ip-64-139-1-69.sjc.megapath.net>

> ); SAEximRunCond expanded to false
> Errors-To: time-nuts-bounces+magnus=rubidium.dyndns.org at febo.com RETRY
> 
> 
> > Make sure not to get near any of the equipment. Free-running
> > oscillators are sensitive to vibration or shock. You've probably heard
> > the story of my best Sulzer oscillator making small phase or jumps
> > which I eventually correlated to when the kids flushed the toilet down
> > the hall. 
> 
> 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.

It is all just as normal filtering, but in the acoustical domain.

Cheers,
Magnus