---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 10/02/18: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:08 AM - Re: OV Protection and AEC 9004-1 module (merlewagner2) 2. 09:02 AM - Re: Lycoming Knock Sensor () 3. 09:40 AM - Re: Lycoming Knock Sensor (chris) 4. 10:47 AM - Re: Lycoming Knock Sensor (skywagon185guy) 5. 12:43 PM - Re: Lycoming Knock Sensor () 6. 03:39 PM - Re: Lycoming Knock Sensor (chris) 7. 04:08 PM - Re: Lycoming Knock Sensor (Deems Herring) ________________________________ Message 1 _____________________________________ Time: 06:08:37 AM PST US Subject: AeroElectric-List: Re: OV Protection and AEC 9004-1 module From: "merlewagner2" Thanks for the info Bob. Any idea if you will come out with the 9004 module in the future? I will go with the warning lite and B&C OV module for now. Regarding the Grumman - can't remember that one. I have trouble remembering my name occasionally.. Serious case of CRS. Merle -------- KC1DNJ General Radiotelephone Commercial SEL A&P Building scale P51, rebuilding Tailwind W10 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=483536#483536 ________________________________ Message 2 _____________________________________ Time: 09:02:32 AM PST US From: Subject: RE: AeroElectric-List: Lycoming Knock Sensor Gentlemen, Thank you for your reply and sorry for the delay in my reply as I was flying all day yesterday. Firstly...THANK YOU for your assistance on this...GREATLY APPRECIATED!!! I have a Lycoming TIO-540 and I run LOP with balanced injectors. I understand the concept of one sensor per cylinder and I also understand that the cylinders on the air-cooled aircraft engine is not as tightly connected to the engine block as a water cooled engine however sound travels through metal quite quickly and I would think that the sound would move from each cylinder head to the block. Would not one sensor mounted on the crankcase "hear" the pings? I can see if I only installed one sensor on the head of cylinder #1 and a pinging in cylinder #6 would have a long way to travel and the sound would distort so the sensor would be unreliable for any cylinder other than its installed #1 position. The Knocksense unit that Bob posted is precisely the one that I was looking at. I was thinking of buying two units and install them at the top of the engine with one closer to the front and the second closer to the back. On the Lyco-Saurus the bottom of the engine has the intake and oil pan so I imagine the liquid and distance from the source of the sound would dampen out the sound. When you order them they ask you for your cylinder diameter so they can tune the sensor to your engine. The next question is.how do you test to see if the darn thing is working? .. Thanks, Bill Hunter From: owner-aeroelectric-list-server@matronics.com On Behalf Of Robert L. Nuckolls, III Sent: Monday, October 1, 2018 10:23 AM Subject: Re: AeroElectric-List: Lycoming Knock Sensor At 11:51 PM 9/30/2018, you wrote: I have never heard of a knock sensor on a Lycoming, even one with electronic mags. I don't see why you couldn't install one in any of the 1/8 NPT primer ports though. Knock sensors are specialized microphones mounted to some sturdy feature of the crankcase. The device is optimized to detect 'knock tones' in the 4-6 Khz range (determined by cylinder bore diameter). There are no plug-n-play sensors . . . i.e. devices that will light a bulb when knocking is detected. They all require some degree of signal conditioning to separate noises of interest from the rest. Here's on example of a product paired with a sensor that will illuminate an annunciator when knocking is detected. https://tinyurl.com/y79tde7s There is a constellation of Arduino based sensor detection projects including sample software https://tinyurl.com/hsq4mee This brings to mind another knowledge nugget I was offered at a Burlington CO fly-in about 15 years ago. The legacy oxygen sensors used on automobiles have been demonstrated to function as advertised in 100LL engines. Met a fellow with an O2 sensor paired with a millivoltmeter on the panel. He asserted that the sensor had several hundred hours on it and had not succumbed to the predicted 'lead fouling' that discouraged use on aircraft engines. One might consider an automotive O2 sensor as an adjunct for achieving consistent mixture settings. Here's a short article on how they work: https://tinyurl.com/ybm74fvh Bob . . . ________________________________ Message 3 _____________________________________ Time: 09:40:28 AM PST US Subject: Re: AeroElectric-List: Lycoming Knock Sensor From: chris Look up efi101.com. This web site has multiple posts on knock or detonation. Will have to do a search to find posts on knock. A very good site. csmale@bak.rr.com On 10/02/2018 09:01 AM, billhuntersemail@gmail.com wrote: > > Gentlemen, > > Thank you for your reply and sorry for the delay in my reply as I was > flying all day yesterday. > > Firstly...THANK YOU for your assistance on this...GREATLY APPRECIATED!!! > > I have a Lycoming TIO-540 and I run LOP with balanced injectors. > > I understand the concept of one sensor per cylinder and I also > understand that the cylinders on the air-cooled aircraft engine is not > as tightly connected to the engine block as a water cooled engine > however sound travels through metal quite quickly and I would think > that the sound would move from each cylinder head to the block. > > Would not one sensor mounted on the crankcase hear the pings? > > I can see if I only installed one sensor on the head of cylinder #1 > and a pinging in cylinder #6 would have a long way to travel and the > sound would distort so the sensor would be unreliable for any cylinder > other than its installed #1 position. > > The Knocksense unit that Bob posted is precisely the one that I was > looking at. I was thinking of buying two units and install them at > the top of the engine with one closer to the front and the second > closer to the back. On the Lyco-Saurus the bottom of the engine has > the intake and oil pan so I imagine the liquid and distance from the > source of the sound would dampen out the sound. When you order them > they ask you for your cylinder diameter so they can tune the sensor to > your engine. > > The next question ishow do you test to see if the darn thing is working? > > > > Thanks, > > Bill Hunter > > *From:* owner-aeroelectric-list-server@matronics.com > *On Behalf Of *Robert > L. Nuckolls, III > *Sent:* Monday, October 1, 2018 10:23 AM > *To:* aeroelectric-list@matronics.com > *Subject:* Re: AeroElectric-List: Lycoming Knock Sensor > > At 11:51 PM 9/30/2018, you wrote: > > I have never heard of a knock sensor on a Lycoming, even one with > electronic mags. I don't see why you couldn't install one in any > of the 1/8 NPT primer ports though. > > > Knock sensors are specialized microphones > mounted to some sturdy feature of the > crankcase. The device is optimized to > detect 'knock tones' in the 4-6 Khz range > (determined by cylinder bore diameter). > > There are no plug-n-play sensors . . . i.e. > devices that will light a bulb when knocking > is detected. They all require some degree > of signal conditioning to separate noises > of interest from the rest. Here's on example > of a product paired with a sensor that > will illuminate an annunciator when knocking > is detected. > > https://tinyurl.com/y79tde7s > > There is a constellation of Arduino based > sensor detection projects including sample > software > > https://tinyurl.com/hsq4mee > > This brings to mind another knowledge nugget > I was offered at a Burlington CO fly-in about > 15 years ago. The legacy oxygen sensors used > on automobiles have been demonstrated to function > as advertised in 100LL engines. Met a fellow > with an O2 sensor paired with a millivoltmeter > on the panel. He asserted that the sensor had > several hundred hours on it and had not succumbed > to the predicted 'lead fouling' that discouraged > use on aircraft engines. > > One might consider an automotive O2 sensor as > an adjunct for achieving consistent mixture > settings. Here's a short article on how they > work: > > https://tinyurl.com/ybm74fvh > > > Bob . . . > ________________________________ Message 4 _____________________________________ Time: 10:47:42 AM PST US From: skywagon185guy Subject: Re: AeroElectric-List: Lycoming Knock Sensor . . .wouldn't you want to mount the sensors such that their sense axis is in the same plane as the knock vibration; namely line up with the piston rods and not on top pf the engine case...? On Tue, Oct 2, 2018 at 9:09 AM wrote: > Gentlemen, > > > Thank you for your reply and sorry for the delay in my reply as I was > flying all day yesterday. > > > Firstly...THANK YOU for your assistance on this...GREATLY APPRECIATED!!! > > > I have a Lycoming TIO-540 and I run LOP with balanced injectors. > > > I understand the concept of one sensor per cylinder and I also understand > that the cylinders on the air-cooled aircraft engine is not as tightly > connected to the engine block as a water cooled engine however sound > travels through metal quite quickly and I would think that the sound woul d > move from each cylinder head to the block. > > > Would not one sensor mounted on the crankcase =9Chear=9D the pings? > > > I can see if I only installed one sensor on the head of cylinder #1 and a > pinging in cylinder #6 would have a long way to travel and the sound woul d > distort so the sensor would be unreliable for any cylinder other than its > installed #1 position. > > > The Knocksense unit that Bob posted is precisely the one that I was > looking at. I was thinking of buying two units and install them at the t op > of the engine with one closer to the front and the second closer to the > back. On the Lyco-Saurus the bottom of the engine has the intake and oil > pan so I imagine the liquid and distance from the source of the sound wou ld > dampen out the sound. When you order them they ask you for your cylinder > diameter so they can tune the sensor to your engine. > > > The next question ishow do you test to see if the darn thing is working? > > > > Thanks, > > Bill Hunter > > > *From:* owner-aeroelectric-list-server@matronics.com < > owner-aeroelectric-list-server@matronics.com> *On Behalf Of *Robert L. > Nuckolls, III > *Sent:* Monday, October 1, 2018 10:23 AM > *To:* aeroelectric-list@matronics.com > *Subject:* Re: AeroElectric-List: Lycoming Knock Sensor > > > At 11:51 PM 9/30/2018, you wrote: > > I have never heard of a knock sensor on a Lycoming, even one with > electronic mags. I don't see why you couldn't install one in any of the 1 /8 > NPT primer ports though. > > > Knock sensors are specialized microphones > mounted to some sturdy feature of the > crankcase. The device is optimized to > detect 'knock tones' in the 4-6 Khz range > (determined by cylinder bore diameter). > > There are no plug-n-play sensors . . . i.e. > devices that will light a bulb when knocking > is detected. They all require some degree > of signal conditioning to separate noises > of interest from the rest. Here's on example > of a product paired with a sensor that > will illuminate an annunciator when knocking > is detected. > > https://tinyurl.com/y79tde7s > > There is a constellation of Arduino based > sensor detection projects including sample > software > > https://tinyurl.com/hsq4mee > > This brings to mind another knowledge nugget > I was offered at a Burlington CO fly-in about > 15 years ago. The legacy oxygen sensors used > on automobiles have been demonstrated to function > as advertised in 100LL engines. Met a fellow > with an O2 sensor paired with a millivoltmeter > on the panel. He asserted that the sensor had > several hundred hours on it and had not succumbed > to the predicted 'lead fouling' that discouraged > use on aircraft engines. > > One might consider an automotive O2 sensor as > an adjunct for achieving consistent mixture > settings. Here's a short article on how they > work: > > https://tinyurl.com/ybm74fvh > > > Bob . . . > ________________________________ Message 5 _____________________________________ Time: 12:43:28 PM PST US From: Subject: RE: AeroElectric-List: Lycoming Knock Sensor >. . .wouldn't you want to mount the sensors such that their sense axis is in the same plane as the knock vibration; namely line up with the piston rods and not on top pf the engine case...? I was kinda wondering the same thing. If I had the money I would buy six knock detection systems and have one sensor per cylinderand if I did the questions would be: -Should one knock sensor be installed on the sidewall of each cylinder? -Or should one knock sensor be installed at the top of the cylinder head near the rocker cover? I am realistically only going to install one or two knock sensors so does the ping sound get transmitted through the metal of the engine to be heard practically everywhere? If so then I imagine only one sensor installed on the crankcase split somewhere in the middle would be sufficient. Yes if you only have one sensor then you really do not know what cylinder is pinging however for my purposes I simply want to halt detonation ASAP and I do not really know care what cylinder. Thanks, Bill Hunter From: owner-aeroelectric-list-server@matronics.com On Behalf Of skywagon185guy Sent: Tuesday, October 2, 2018 10:47 AM Subject: Re: AeroElectric-List: Lycoming Knock Sensor . . .wouldn't you want to mount the sensors such that their sense axis is in the same plane as the knock vibration; namely line up with the piston rods and not on top pf the engine case...? On Tue, Oct 2, 2018 at 9:09 AM > wrote: Gentlemen, Thank you for your reply and sorry for the delay in my reply as I was flying all day yesterday. Firstly...THANK YOU for your assistance on this...GREATLY APPRECIATED!!! I have a Lycoming TIO-540 and I run LOP with balanced injectors. I understand the concept of one sensor per cylinder and I also understand that the cylinders on the air-cooled aircraft engine is not as tightly connected to the engine block as a water cooled engine however sound travels through metal quite quickly and I would think that the sound would move from each cylinder head to the block. Would not one sensor mounted on the crankcase =9Chear=9D the pings? I can see if I only installed one sensor on the head of cylinder #1 and a pinging in cylinder #6 would have a long way to travel and the sound would distort so the sensor would be unreliable for any cylinder other than its installed #1 position. The Knocksense unit that Bob posted is precisely the one that I was looking at. I was thinking of buying two units and install them at the top of the engine with one closer to the front and the second closer to the back. On the Lyco-Saurus the bottom of the engine has the intake and oil pan so I imagine the liquid and distance from the source of the sound would dampen out the sound. When you order them they ask you for your cylinder diameter so they can tune the sensor to your engine. The next question ishow do you test to see if the darn thing is working? Thanks, Bill Hunter From: owner-aeroelectric-list-server@matronics.com > On Behalf Of Robert L. Nuckolls, III Sent: Monday, October 1, 2018 10:23 AM Subject: Re: AeroElectric-List: Lycoming Knock Sensor At 11:51 PM 9/30/2018, you wrote: I have never heard of a knock sensor on a Lycoming, even one with electronic mags. I don't see why you couldn't install one in any of the 1/8 NPT primer ports though. Knock sensors are specialized microphones mounted to some sturdy feature of the crankcase. The device is optimized to detect 'knock tones' in the 4-6 Khz range (determined by cylinder bore diameter). There are no plug-n-play sensors . . . i.e. devices that will light a bulb when knocking is detected. They all require some degree of signal conditioning to separate noises of interest from the rest. Here's on example of a product paired with a sensor that will illuminate an annunciator when knocking is detected. https://tinyurl.com/y79tde7s There is a constellation of Arduino based sensor detection projects including sample software https://tinyurl.com/hsq4mee This brings to mind another knowledge nugget I was offered at a Burlington CO fly-in about 15 years ago. The legacy oxygen sensors used on automobiles have been demonstrated to function as advertised in 100LL engines. Met a fellow with an O2 sensor paired with a millivoltmeter on the panel. He asserted that the sensor had several hundred hours on it and had not succumbed to the predicted 'lead fouling' that discouraged use on aircraft engines. One might consider an automotive O2 sensor as an adjunct for achieving consistent mixture settings. Here's a short article on how they work: https://tinyurl.com/ybm74fvh Bob . . . ________________________________ Message 6 _____________________________________ Time: 03:39:18 PM PST US Subject: Re: AeroElectric-List: Lycoming Knock Sensor From: chris knock sensing is quite complex. Search efi101.com forums for posts on knock sensing. It will give you and idea of how to go about doing your proposal. csmale@bak.rr.com On 10/02/2018 12:42 PM, billhuntersemail@gmail.com wrote: > > >. . .wouldn't you want to mount the sensors such that their sense > axis is in the same plane as the knock vibration; namely line up with > the piston rods and not on top pf the engine case...? > > I was kinda wondering the same thing. > > If I had the money I would buy six knock detection systems and have > one sensor per cylinderand if I did the questions would be: > > -Should one knock sensor be installed on the sidewall of each cylinder? > > -Or should one knock sensor be installed at the top of the cylinder > head near the rocker cover? > > I am realistically only going to install one or two knock sensors so > does the ping sound get transmitted through the metal of the engine to > be heard practically everywhere? If so then I imagine only one sensor > installed on the crankcase split somewhere in the middle would be > sufficient. Yes if you only have one sensor then you really do not > know what cylinder is pinging however for my purposes I simply want to > halt detonation ASAP and I do not really know care what cylinder. > > > > Thanks, > > Bill Hunter > > *From:* owner-aeroelectric-list-server@matronics.com > *On Behalf Of > *skywagon185guy > *Sent:* Tuesday, October 2, 2018 10:47 AM > *To:* aeroelectric list > *Subject:* Re: AeroElectric-List: Lycoming Knock Sensor > > . . .wouldn't you want to mount the sensors such that their sense axis > is in the same plane as the knock vibration; namely line up with the > piston rods and not on top pf the engine case...? > > On Tue, Oct 2, 2018 at 9:09 AM > wrote: > > Gentlemen, > > Thank you for your reply and sorry for the delay in my reply as I > was flying all day yesterday. > > Firstly...THANK YOU for your assistance on this...GREATLY > APPRECIATED!!! > > I have a Lycoming TIO-540 and I run LOP with balanced injectors. > > I understand the concept of one sensor per cylinder and I also > understand that the cylinders on the air-cooled aircraft engine is > not as tightly connected to the engine block as a water cooled > engine however sound travels through metal quite quickly and I > would think that the sound would move from each cylinder head to > the block. > > Would not one sensor mounted on the crankcase hear the pings? > > I can see if I only installed one sensor on the head of cylinder > #1 and a pinging in cylinder #6 would have a long way to travel > and the sound would distort so the sensor would be unreliable for > any cylinder other than its installed #1 position. > > The Knocksense unit that Bob posted is precisely the one that I > was looking at. I was thinking of buying two units and install > them at the top of the engine with one closer to the front and the > second closer to the back. On the Lyco-Saurus the bottom of the > engine has the intake and oil pan so I imagine the liquid and > distance from the source of the sound would dampen out the sound. > When you order them they ask you for your cylinder diameter so > they can tune the sensor to your engine. > > The next question ishow do you test to see if the darn thing is > working? > > > > Thanks, > > Bill Hunter > > *From:* owner-aeroelectric-list-server@matronics.com > > > *On Behalf > Of *Robert L. Nuckolls, III > *Sent:* Monday, October 1, 2018 10:23 AM > *To:* aeroelectric-list@matronics.com > > *Subject:* Re: AeroElectric-List: Lycoming Knock Sensor > > At 11:51 PM 9/30/2018, you wrote: > > I have never heard of a knock sensor on a Lycoming, even one > with electronic mags. I don't see why you couldn't install one > in any of the 1/8 NPT primer ports though. > > > Knock sensors are specialized microphones > mounted to some sturdy feature of the > crankcase. The device is optimized to > detect 'knock tones' in the 4-6 Khz range > (determined by cylinder bore diameter). > > There are no plug-n-play sensors . . . i.e. > devices that will light a bulb when knocking > is detected. They all require some degree > of signal conditioning to separate noises > of interest from the rest. Here's on example > of a product paired with a sensor that > will illuminate an annunciator when knocking > is detected. > > https://tinyurl.com/y79tde7s > > There is a constellation of Arduino based > sensor detection projects including sample > software > > https://tinyurl.com/hsq4mee > > This brings to mind another knowledge nugget > I was offered at a Burlington CO fly-in about > 15 years ago. The legacy oxygen sensors used > on automobiles have been demonstrated to function > as advertised in 100LL engines. Met a fellow > with an O2 sensor paired with a millivoltmeter > on the panel. He asserted that the sensor had > several hundred hours on it and had not succumbed > to the predicted 'lead fouling' that discouraged > use on aircraft engines. > > One might consider an automotive O2 sensor as > an adjunct for achieving consistent mixture > settings. Here's a short article on how they > work: > > https://tinyurl.com/ybm74fvh > > > Bob . . . > ________________________________ Message 7 _____________________________________ Time: 04:08:32 PM PST US From: Deems Herring Subject: Re: AeroElectric-List: Lycoming Knock Sensor Here is a link to a paper about setting up knock sensing with a link to an IC used for processing. http://www.ti.com/lit/an/slyt580/slyt580.pdf Deems Herring ________________________________________ From: owner-aeroelectric-list-server@matronics.com on behalf of chris Sent: Tuesday, October 2, 2018 6:37 PM Subject: Re: AeroElectric-List: Lycoming Knock Sensor knock sensing is quite complex. Search efi101.com forums for posts on knock sensing. It will give you and idea of how to go about doing your proposal. csmale@bak.rr.com On 10/02/2018 12:42 PM, billhuntersemail@gmail.com wrote: >. . .wouldn't you want to mount the sensors such that their sense axis is in the same plane as the knock vibration; namely line up with the piston rods and not on top pf the engine case...? I was kinda wondering the same thing. If I had the money I would buy six knock detection systems and have one sensor per cylinderand if I did the questions would be: -Should one knock sensor be installed on the sidewall of each cylinder? -Or should one knock sensor be installed at the top of the cylinder head near the rocker cover? I am realistically only going to install one or two knock sensors so does the ping sound get transmitted through the metal of the engine to be heard practically everywhere? If so then I imagine only one sensor installed on the crankcase split somewhere in the middle would be sufficient. Yes if you only have one sensor then you really do not know what cylinder is pinging however for my purposes I simply want to halt detonation ASAP and I do not really know care what cylinder. Thanks, Bill Hunter From: owner-aeroelectric-list-server@matronics.com On Behalf Of skywagon185guy Sent: Tuesday, October 2, 2018 10:47 AM Subject: Re: AeroElectric-List: Lycoming Knock Sensor . . .wouldn't you want to mount the sensors such that their sense axis is in the same plane as the knock vibration; namely line up with the piston rods and not on top pf the engine case...? On Tue, Oct 2, 2018 at 9:09 AM > wrote: Gentlemen, Thank you for your reply and sorry for the delay in my reply as I was flying all day yesterday. Firstly...THANK YOU for your assistance on this...GREATLY APPRECIATED!!! I have a Lycoming TIO-540 and I run LOP with balanced injectors. I understand the concept of one sensor per cylinder and I also understand that the cylinders on the air-cooled aircraft engine is not as tightly connected to the engine block as a water cooled engine however sound travels through metal quite quickly and I would think that the sound would move from each cylinder head to the block. Would not one sensor mounted on the crankcase hear the pings? I can see if I only installed one sensor on the head of cylinder #1 and a pinging in cylinder #6 would have a long way to travel and the sound would distort so the sensor would be unreliable for any cylinder other than its installed #1 position. The Knocksense unit that Bob posted is precisely the one that I was looking at. I was thinking of buying two units and install them at the top of the engine with one closer to the front and the second closer to the back. On the Lyco-Saurus the bottom of the engine has the intake and oil pan so I imagine the liquid and distance from the source of the sound would dampen out the sound. When you order them they ask you for your cylinder diameter so they can tune the sensor to your engine. The next question ishow do you test to see if the darn thing is working? Thanks, Bill Hunter From: owner-aeroelectric-list-server@matronics.com > On Behalf Of Robert L. Nuckolls, III Sent: Monday, October 1, 2018 10:23 AM Subject: Re: AeroElectric-List: Lycoming Knock Sensor At 11:51 PM 9/30/2018, you wrote: I have never heard of a knock sensor on a Lycoming, even one with electronic mags. I don't see why you couldn't install one in any of the 1/8 NPT primer ports though. Knock sensors are specialized microphones mounted to some sturdy feature of the crankcase. The device is optimized to detect 'knock tones' in the 4-6 Khz range (determined by cylinder bore diameter). There are no plug-n-play sensors . . . i.e. devices that will light a bulb when knocking is detected. They all require some degree of signal conditioning to separate noises of interest from the rest. Here's on example of a product paired with a sensor that will illuminate an annunciator when knocking is detected. https://tinyurl.com/y79tde7s There is a constellation of Arduino based sensor detection projects including sample software https://tinyurl.com/hsq4mee This brings to mind another knowledge nugget I was offered at a Burlington CO fly-in about 15 years ago. The legacy oxygen sensors used on automobiles have been demonstrated to function as advertised in 100LL engines. Met a fellow with an O2 sensor paired with a millivoltmeter on the panel. He asserted that the sensor had several hundred hours on it and had not succumbed to the predicted 'lead fouling' that discouraged use on aircraft engines. One might consider an automotive O2 sensor as an adjunct for achieving consistent mixture settings. Here's a short article on how they work: https://tinyurl.com/ybm74fvh 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.