X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-db03.mx.aol.com ([205.188.91.97] verified) by logan.com (CommuniGate Pro SMTP 5.4.0) with ESMTP id 5046980 for flyrotary@lancaironline.net; Sat, 09 Jul 2011 12:52:38 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.91.97; envelope-from=Bktrub@aol.com Received: from imo-da04.mx.aol.com (imo-da04.mx.aol.com [205.188.169.202]) by imr-db03.mx.aol.com (8.14.1/8.14.1) with ESMTP id p69Gptd4016146 for ; Sat, 9 Jul 2011 12:51:55 -0400 Received: from Bktrub@aol.com by imo-da04.mx.aol.com (mail_out_v42.9.) id q.10e7.346f6c3 (55741) for ; Sat, 9 Jul 2011 12:51:51 -0400 (EDT) Received: from smtprly-me01.mx.aol.com (smtprly-me01.mx.aol.com [64.12.95.102]) by cia-md04.mx.aol.com (v129.10) with ESMTP id MAILCIAMD048-b2924e188725139; Sat, 09 Jul 2011 12:51:50 -0400 Received: from webmail-d081 (webmail-d081.sim.aol.com [205.188.181.107]) by smtprly-me01.mx.aol.com (v129.10) with ESMTP id MAILSMTPRLYME012-b2924e188725139; Sat, 09 Jul 2011 12:51:49 -0400 References: To: flyrotary@lancaironline.net Subject: Re: [FlyRotary] Re: sheilded plug wires Date: Sat, 09 Jul 2011 12:51:49 -0400 X-AOL-IP: 50.46.146.205 In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: bktrub@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8CE0C6FA1261A54_E70_27AC6_webmail-d081.sysops.aol.com" X-Mailer: AOL Webmail 33953-STANDARD Received: from 50.46.146.205 by webmail-d081.sysops.aol.com (205.188.181.107) with HTTP (WebMailUI); Sat, 09 Jul 2011 12:51:49 -0400 Message-Id: <8CE0C6FA11EF631-E70-12621@webmail-d081.sysops.aol.com> X-Spam-Flag:NO X-AOL-SENDER: Bktrub@aol.com ----------MB_8CE0C6FA1261A54_E70_27AC6_webmail-d081.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii" Ok, theory is nice, I prefer to just think it is all magic. My apologies,= but I am the product of our public school system : ) What I'd like to know is this- am I fabricating the wires correctly? I cut= the insulation about 1/2 inch back from the inner conductor, and then cri= mp the terminal so that the conductor is folded back against the wire unde= r the terminal crimp. There is no outer braid or anything which actually grounds against the eng= ine. I am thinking of putting an outer braid around the wires and then gro= unding that on one end.=20 Brian Trubee -----Original Message----- From: Charlie England To: Rotary motors in aircraft Sent: Sat, Jul 9, 2011 9:11 am Subject: [FlyRotary] Re: sheilded plug wires To expand on that for the electron-challenged, an inductor is effectively= a frequency dependent resistor. The higher the frequency, the higher the= resistance. So, the fundamental pulse to the plug makes it through (thoug= h slowed slightly), while the harmonics (noise) that were generated can't= get past the extra resistance presented to them. The reverse is true for a capacitor. That's one of the reasons why you see= capacitors with one leg tied to the power supply & the other to ground.= The capacitor blocks DC but passes higher frequencies (the noise) to grou= nd. I have no doubt that the above will make physicists cringe, but it's close= enough to working knowledge for us builders to use. Charlie On 07/09/2011 08:28 AM, Tracy wrote:=20 In this case "shielded" is the wrong term. The spiral wire does not actu= ally shield the noise, it prevents the noise from being transmitted. It= acts as an inductor to prevent the propagation of the noise generated at= the spark gap from propagating up the wire. Tracy Sent from my iPad On Jul 9, 2011, at 2:09 AM, Lehanover@aol.com wrote: It has to do with the resistance of the long thin Monel wire. An impedance= mismatch and inductive reactance. What the mechanism is I do not know. Th= at is why Tracy is here, to explain such matters. =20 Lynn E. Hanover =20 In a message dated 7/8/2011 11:08:09 P.M. Paraguay Standard Time, SBoese@u= wyo.edu writes: My last massage got a little garbled, the way I have my wires configured= now, the conductor and spiral wrap are exposed and folded under the crimp= ed teminal ends, so aren't both the conductor and the spiral wrap acting= as a conductor? What is doing the shielding? =20 Brian Trubee ----------MB_8CE0C6FA1261A54_E70_27AC6_webmail-d081.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="us-ascii"
Ok,  theory is nice,= I prefer to just think it is all magic. My apologies, but I am= the product of our public school system : )
 
What I'd like to know is= this- am I fabricating the wires correctly? I cut the insulation abo= ut 1/2 inch back from the inner conductor, and then crimp the terminal so= that the conductor is folded back against the wire under the terminal cri= mp.
There is no outer braid or anything which actually grounds against th= e engine. I am thinking of putting an outer braid around the wires and the= n grounding that on one end.
 
Brian Trubee



-----Original Message-----
From: Charlie England <ceengland@bellsouth.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Sat, Jul 9, 2011 9:11 am
Subject: [FlyRotary] Re: sheilded plug wires

To expand on= that for the electron-challenged, an inductor is effectively a frequency= dependent resistor. The higher the frequency, the higher the resistance.= So, the fundamental pulse to the plug makes it through (though slowed sli= ghtly), while the harmonics (noise) that were generated  can't get pa= st the extra resistance presented to them.

The reverse is true for a capacitor. That's one of the reasons why you see= capacitors with one leg tied to the power supply & the other to groun= d. The capacitor blocks DC but passes higher frequencies (the noise) to gr= ound.

I have no doubt that the above will make physicists cringe, but it's close= enough to working knowledge for us builders to use.

Charlie

On 07/09/2011 08:28 AM, Tracy wrote:=20
In this case "shielded" is the wrong term.   The spiral wire doe= s not actually shield the noise, it prevents the noise from being transmit= ted.    It acts as an inductor to prevent the propagation of the= noise generated at the spark gap from propagating up the wire.

Tracy

Sent from my iPad

On Jul 9, 2011, at 2:09 AM, Lehanover= @aol.com wrote:

It has to do with the resistance of the long thin Monel wire. An impe= dance mismatch and inductive reactance. What the mechanism is I do not kno= w. That is why Tracy is here, to explain such matters.
 
Lynn E. Hanover
 
In a message dated 7/8/2011 11:08:09 P.M. Paraguay Standard Time, SBoese@uwyo.edu writes:
My last massage got a little garbled, the way I have my wires configu= red now, the conductor and spiral wrap are exposed and folded under the cr= imped teminal ends, so aren't both the conductor and the spiral wrap actin= g as a conductor? What is doing the shielding?
 
Brian Trubee

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