1995-07-12 - Re: EMI (was: Re: Don’t trust the net too much)

Header Data

From: “Ed Carp [khijol Sysadmin]” <erc@khijol.intele.net>
To: perobich@ingr.com
Message Hash: d22884cf1caa730aea2a422825c45bccd1df57fcc544de452492f803a887fb7a
Message ID: <Pine.3.89.9507121207.B3180-0100000@khijol>
Reply To: <199507121749.AA12206@poboy.b17c.ingr.com>
UTC Datetime: 1995-07-12 18:14:57 UTC
Raw Date: Wed, 12 Jul 95 11:14:57 PDT

Raw message

From: "Ed Carp [khijol Sysadmin]" <erc@khijol.intele.net>
Date: Wed, 12 Jul 95 11:14:57 PDT
To: perobich@ingr.com
Subject: Re: EMI (was: Re: Don't trust the net too much)
In-Reply-To: <199507121749.AA12206@poboy.b17c.ingr.com>
Message-ID: <Pine.3.89.9507121207.B3180-0100000@khijol>
MIME-Version: 1.0
Content-Type: text/plain


On Wed, 12 Jul 1995, Paul Robichaux wrote:

> -----BEGIN PGP SIGNED MESSAGE-----
> 
> Ed Carp said:
> 
> > This sounds like absolute propoganda.  If you do the calculations, you'll 
> > see that a 1 watt transmitter sitting 100 feet away from your target will 
> > generate an EMF less than that 1000kW ERP TV transmitter array you just 
> > flew over.  If aircraft avionics were *that* sensitive, we'd have planes 
> > falling out of the sky, and we don't. 
> 
> Oh, yes-- we do. The Army lost a small number (two or three) of of
> UH-60 Black Hawks in crashes where the flight control system suddenly
> commanded extreme pitch or attitude changes. Why? In all the crash
> cases, EMI from nearby TV or FM transmitters was found to be the
> proximate cause. The Army, and Sikorsky, immediately went to work to
> better shield the FCS from EMI.
> 
> It's interesting to note that the Navy's SH-60, a UH-60 variant, was
> designed from the start to be EMI-immune. Ships' radars operate in the
> 10-100kW range, and that's a lot of EMI when you're landing 15-20m
> away from the radar mast.

Well, I was speaking of commercial aircraft, not military, but the point 
is taken.  I haven't had occasion to use my packet radio lashup on a 
UH-60 -- yet ;)
--
Ed Carp, N7EKG    			Ed.Carp@linux.org, ecarp@netcom.com
801/534-8857 voicemail			801/460-1883 digital pager
Finger ecarp@netcom.com for PGP 2.5 public key		an88744@anon.penet.fi

Q.	What's the trouble with writing an MS-DOS program to emulate Clinton?
A.	Figuring out what to do with the other 639K of memory.






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