---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 03/03/17: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:10 AM - Bending a SS VOR antenna (whodja) 2. 06:00 AM - M27500 Shielded Wire For Strobe (William Hunter) 3. 06:48 AM - Re: M27500 Shielded Wire For Strobe (Robert L. Nuckolls, III) 4. 11:16 AM - Re: M27500 Shielded Wire For Strobe (William Hunter) 5. 12:45 PM - Re: 3PDT switch swap for relay? (user9253) 6. 02:45 PM - Re: M27500 Shielded Wire For Strobe (Robert L. Nuckolls, III) 7. 04:08 PM - Re: M27500 Shielded Wire For Strobe (William Hunter) ________________________________ Message 1 _____________________________________ Time: 05:10:40 AM PST US Subject: AeroElectric-List: Bending a SS VOR antenna From: "whodja" Any recommendations on bending a SS VOR antenna? Based on a modified mount my antennas come out of the mount at 90 and I would like to bend them to 45. Heat or no heat? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=466821#466821 ________________________________ Message 2 _____________________________________ Time: 06:00:55 AM PST US From: William Hunter Subject: AeroElectric-List: M27500 Shielded Wire For Strobe Greetings, I am wiring a Velocity composite aircraft. For my Whelen HDACF strobe light circuit I was planning on using the gold colored copper strand lamp cord from Home Depot... just kidding... I am actually planning on using Tefzel M22759/16 wire 18 guage from the CB to the overhead switch and then from the switch way back to the strobe unit mounted on the firewall (pusher airplane). Then... I read "somewhere" that the M27500 Shielded wire is recommended for this application so as to suppress the noise. Is this really necessary? THANKS!!! Bill Hunter ________________________________ Message 3 _____________________________________ Time: 06:48:13 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: M27500 Shielded Wire For Strobe At 07:58 AM 3/3/2017, you wrote: >Greetings,=C2 > >I am wiring a Velocity composite aircraft.=C2 > >For my Whelen HDACF strobe light circuit I was >planning on using the gold colored copper strand >lamp cord from Home Depot... just kidding... I >am actually planning on using Tefzel M22759/16 >wire 18 guage from the CB to the overhead switch >and then from the switch way back to the strobe >unit mounted on the firewall (pusher airplane).=C2 > >Then... I read "somewhere" that the M27500 >Shielded wire is recommended for this >application so as to suppress the noise.=C2 > >Is this really necessary?=C2 Shielding of wires breaks only ONE kind of noise propagation mode. This mode is very weak and then only applies to certain kinds of fast rising antagonists. No such antagonists exist on the DC power line to any modern piece of electronics . . . if it DOES demonstrate such antagonists, then those will be CONDUCTED into the rest of the system whether the wire is shielded or not . . . short answer: No Bob . . . ________________________________ Message 4 _____________________________________ Time: 11:16:22 AM PST US From: William Hunter Subject: Re: AeroElectric-List: M27500 Shielded Wire For Strobe Wow... Bob and Simon I am very grateful for your time. I cannot contribute much back to this forum however on other forums where I have some tid bits of ignorance to expound upon I try to help where I can so as to "cyber pay it forward". Yes it seemed odd to me to have to shield a DC supply wire to the power inputs of a DC unit. Output wires from the strobe box to the strobe lights on the wings could have a argument. I will certainly twist the power feed wire pairs as suggested for this box. I also have two Light Speed Plasma III ignition units and two aircraft batteries. Since Klaus recommends running the POS and NEG wires directly from the battery terminals (through a reset able CB) to the units I will also twist those pairs. My power feeds from the associated CB to the radios is a very small run and there is no negative wire nearby to twist so I guess that is a wash. I do have some other wires from DC CBs to switches and then to appliances such as landing /taxi/beacon /voltage regulators and some of those wires runs will be bundled next to the XPNDR /ADS-B /NAV/COM coaxial cables (using the coaxial cable Bob recommended). I suppose the shield on the coax will do the trick. Bill Hunter On Mar 3, 2017 09:56, "Robert L. Nuckolls, III" < nuckolls.bob@aeroelectric.com> wrote: > At 07:58 AM 3/3/2017, you wrote: > > Greetings,=C3=82 > > I am wiring a Velocity composite aircraft.=C3=82 > > For my Whelen HDACF strobe light circuit I was planning on using the gold > colored copper strand lamp cord from Home Depot... just kidding... I am > actually planning on using Tefzel M22759/16 wire 18 guage from the CB to > the overhead switch and then from the switch way back to the strobe unit > mounted on the firewall (pusher airplane).=C3=82 > > Then... I read "somewhere" that the M27500 Shielded wire is recommended > for this application so as to suppress the noise.=C3=82 > > Is this really necessary?=C3=82 > > > Shielding of wires breaks only ONE kind > of noise propagation mode. This mode is very weak > and then only applies to certain kinds of > fast rising antagonists. No such antagonists exist > on the DC power line to any modern piece of > electronics . . . if it DOES demonstrate such > antagonists, then those will be CONDUCTED into > the rest of the system whether the wire is shielded > or not . . . short answer: > > No > > > Bob . . . > ________________________________ Message 5 _____________________________________ Time: 12:45:30 PM PST US Subject: AeroElectric-List: Re: 3PDT switch swap for relay? From: "user9253" Cozy Nose Gear circuit is attached. I do not have a Cozy. If switch is in "UP" position and airspeed is greater than 40 and less than 90 and if throttle is closed and if altitude is less than 350 feet, then "AUTO" relay will energize and hold. The "UP" relay will drop out (if it was energized). The "DOWN" relay will energize. The "AUTO" relay will remain energized and holding until the switch is moved to the center, off, position or moved to the down position. "Auto down" is disabled when switch is off. Comments and criticism welcome. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=466838#466838 Attachments: http://forums.matronics.com//files/cozy_nose_gear_185.jpg ________________________________ Message 6 _____________________________________ Time: 02:45:54 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: M27500 Shielded Wire For Strobe At 01:13 PM 3/3/2017, you wrote: >Wow... Bob and Simon I am very grateful for your >time. I cannot contribute much back to this >forum however on other forums where I have some >tid bits of ignorance to expound upon I try to >help where I can so as to "cyber pay it forward".=C2 > >Yes it seemed odd to me to have to shield a DC >supply wire to the power inputs of a DC unit. >Output wires from the strobe box to the strobe >lights on the wings could have a argument.=C2 > >I will certainly twist the power feed wire pairs as suggested for this box.=C2 > >I also have two Light Speed Plasma III ignition >units and two aircraft batteries. Since Klaus >recommends running the POS and NEG wires >directly from the battery terminals (through a >reset able CB) to the units I will also twist those pairs.=C2 That's a bit of OVERKILL . . . strike that . . . it's a LOT of overkill. Klaus and I had had some discussions about it and he didn't disagree with me but still seems to get some kind of comfort/satisfaction from running wires directly to batteries. Failure mode effects analysis and simple probability studies demonstrate that each ignition simply needs its own power source with no chance of single failure bringing down both ignition systems. A prime example of yet another flavor of poor FMEA is illustrated here: http://tinyurl.com/msfmldj If I were putting Lightspeed (or any other pair of engine support accessories) in a TC aircraft, I think my DARs would be happy with one ignition powered from the battery bus on its own breaker/fuse and powering the other from the main bus . . it too powered by its own protection. Ground the accessories locally (metal airplane) or to the grounding hub on the firewall (see Figure Z-15). Twisting the power/ground pairs is of no value in reduction of noise. If the accessory dumps and excessive level of noise back to the bus then shielding/twisting won't help . . . furhter, the product would not pass DO-160 qualification testing for installation on a TC aircraft. >My power feeds from the associated CB to the >radios is a very small run and there is no >negative wire nearby to twist so I guess that is a wash.=C2 Scrap the twisting thing . . . >I do have some other wires from DC CBs to >switches and then to appliances such as landing >/taxi/beacon /voltage regulators and some of >those wires runs will be bundled next to the >XPNDR /ADS-B /NAV/COM coaxial cables (using the >coaxial cable Bob recommended). I suppose the >shield on the coax will do the trick.=C2 Your filtering apples out of your sack of oranges. Shields on coaxes have a completely different task . . . they have nothing in common with shielding as a noise abatement device. Coaxes bundled with virtually any other wires raises no concerns for inter-system interference. Bob . . . ________________________________ Message 7 _____________________________________ Time: 04:08:41 PM PST US From: William Hunter Subject: Re: AeroElectric-List: M27500 Shielded Wire For Strobe Thanks Bob for the valuable information!!! Bill Hunter On Mar 3, 2017 16:55, "Robert L. Nuckolls, III" < nuckolls.bob@aeroelectric.com> wrote: > At 01:13 PM 3/3/2017, you wrote: > > Wow... Bob and Simon I am very grateful for your time. I cannot contribut e > much back to this forum however on other forums where I have some tid bit s > of ignorance to expound upon I try to help where I can so as to "cyber pa y > it forward".=C3=82 > > Yes it seemed odd to me to have to shield a DC supply wire to the power > inputs of a DC unit. Output wires from the strobe box to the strobe light s > on the wings could have a argument.=C3=82 > > I will certainly twist the power feed wire pairs as suggested for this > box.=C3=82 > > I also have two Light Speed Plasma III ignition units and two aircraft > batteries. Since Klaus recommends running the POS and NEG wires directly > from the battery terminals (through a reset able CB) to the units I will > also twist those pairs.=C3=82 > > > That's a bit of OVERKILL . . . strike that . . . > it's a LOT of overkill. Klaus and I had > had some discussions about it and he didn't > disagree with me but still seems to get some kind > of comfort/satisfaction from running wires directly > to batteries. > > Failure mode effects analysis and simple probability > studies demonstrate that each ignition simply needs > its own power source with no chance of single failure > bringing down both ignition systems. A prime example > of yet another flavor of poor FMEA is illustrated > here: http://tinyurl.com/msfmldj > > If I were putting Lightspeed (or any other pair > of engine support accessories) in a TC aircraft, > I think my DARs would be happy with one ignition > powered from the battery bus on its own breaker/fuse > and powering the other from the main bus . . it > too powered by its own protection. Ground the > accessories locally (metal airplane) or to the > grounding hub on the firewall (see Figure Z-15). > > Twisting the power/ground pairs is of no value > in reduction of noise. If the accessory dumps > and excessive level of noise back to the bus then > shielding/twisting won't help . . . furhter, the > product would not pass DO-160 qualification > testing for installation on a TC aircraft. > > My power feeds from the associated CB to the radios is a very small run > and there is no negative wire nearby to twist so I guess that is a wash. =C3=82 > > > Scrap the twisting thing . . . > > > I do have some other wires from DC CBs to switches and then to appliances > such as landing /taxi/beacon /voltage regulators and some of those wires > runs will be bundled next to the XPNDR /ADS-B /NAV/COM coaxial cables > (using the coaxial cable Bob recommended). I suppose the shield on the co ax > will do the trick.=C3=82 > > > Your filtering apples out of your sack of > oranges. Shields on coaxes have a completely > different task . . . they have nothing in > common with shielding as a noise abatement > device. Coaxes bundled with virtually > any other wires raises no concerns for > inter-system interference. > > Bob . . . > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.