From: MDAeroInc@aol.com
Message-ID: <81be43d1.24d67cf4@aol.com>
Date: Mon, 2 Aug 1999 00:47:48 EDT
Subject: Sandel/S-Tec Compatablility
To: lancair.list@olsusa.com
Mime-Version: 1.0

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For those of you interested in the Sandel HSI, & S-Tec Gyro's. I've recently 
found out that the incompatability was due to noisy signals from the gyro to 
the Digital HSI.  The noise isn't a concern when using an analog mechanical 
HSI, which doesn't respond fast enough to show the effects of the noise.  But 
when you couple this noise to a digital instrument it will display a 
constantly moving heading by about 1-2 degree back & forth.  Well Sandel & 
S-Tec are getting together and they are incorporating a noise filter board 
into future Gyro's & can retrofit earlier one's.  Currently they are in the 
process of certifying the change with the FAA. So those of you with the 
desire to use the Sandel/S-tec combination, take heart, it is a real 
consideration now.

I'll keep you posted as I find out more. 
Mike DeHate Jr.
M.D.Aero Inc
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