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X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: <13brv3@bellsouth.net> Received: from imf17aec.mail.bellsouth.net ([205.152.59.65] verified) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTP id 950982 for flyrotary@lancaironline.net; Fri, 20 May 2005 10:35:00 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.65; envelope-from=13brv3@bellsouth.net Received: from ibm57aec.bellsouth.net ([65.6.194.9]) by imf17aec.mail.bellsouth.net (InterMail vM.5.01.06.11 201-253-122-130-111-20040605) with ESMTP id <20050520143412.NSWN2331.imf17aec.mail.bellsouth.net@ibm57aec.bellsouth.net> for ; Fri, 20 May 2005 10:34:12 -0400 Received: from rd ([65.6.194.9]) by ibm57aec.bellsouth.net (InterMail vG.1.02.00.01 201-2136-104-101-20040929) with ESMTP id <20050520143412.XEWR23538.ibm57aec.bellsouth.net@rd> for ; Fri, 20 May 2005 10:34:12 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] EC-2 shileded cables was Re: More MAP measurement questions Date: Fri, 20 May 2005 09:34:30 -0500 Message-ID: <010b01c55d49$0876db10$6101a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_010C_01C55D1F.1FA0D310" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 This is a multi-part message in MIME format. ------=_NextPart_000_010C_01C55D1F.1FA0D310 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable I have been tracking your progress on the EC2. One thing about using shielded cables. Both ends need to be grounded and do not use the shield as a conductor for any function. Data running in adjacent cables = can be corrupted by currents in cables next to them. If the shields = are not grounded at both ends you have created an antenna. Good luck. =20 Hi Joe,=20 =20 I think what you just recommended goes against standard practice (as I understand it). You want your ground for a device to be a dedicated = ground, but when you start connecting shields between devices, you give each = device multiple little grounds as well. This actually sets up the potential = for "ground loops", where you are actually allowing current to flow through = the shields between devices. =20 =20 I would only ground one end, and it would be the end that has the main component, with the best ground (EC-2 box in this case). =20 =20 Cheers, Rusty (stand still around my MRI sites and I'll ground your shoes)=20 ------=_NextPart_000_010C_01C55D1F.1FA0D310 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

I have been = tracking your progress on the EC2. One thing about using shielded=20 cables. Both ends need to be grounded and do not use the shield as = a=20 conductor for any function. Data running in adjacent cables can be = corrupted by currents in cables next to=20 them. If the shields are not grounded at both ends you have = created an=20 antenna. Good luck.

Hi=20 Joe,

I think what=20 you just recommended goes against standard practice (as I = understand=20 it). You want your ground for a device to be a dedicated ground, = but when=20 you start connecting shields between devices, you give each device = multiple=20 little grounds as well. This actually sets up the = potential for=20 "ground loops", where you are actually allowing current to=20 flow through the shields between = devices.

I would only=20 ground one end, and it would be the end that has the main component, = with the=20 best ground (EC-2 box in this case).

Cheers,

Rusty (stand=20 still around my MRI sites and I'll ground your=20 shoes)

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