---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 06/17/07: 18 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:40 AM - Re: Marker beacon antenna for composite (Robert L. Nuckolls, III) 2. 06:41 AM - Re: Re: MB antennnas (Robert L. Nuckolls, III) 3. 06:50 AM - Re: Marker beacon antenna for composite aircraft (Robert L. Nuckolls, III) 4. 06:50 AM - Re: (Robert L. Nuckolls, III) 5. 06:55 AM - Re: Stupid question I'm sure (Robert L. Nuckolls, III) 6. 06:55 AM - Re: Re: MB antennnas (Robert L. Nuckolls, III) 7. 08:01 AM - Re: Stupid question I'm sure (Alan Adamson) 8. 08:09 AM - Re: Stupid question I'm sure (Robert Feldtman) 9. 08:13 AM - Re: Re: MB antennnas (Bob McCallum) 10. 09:40 AM - Re: Re: MB antennnas (Robert L. Nuckolls, III) 11. 05:59 PM - Antenna doubler plate - prime or not (Ralph E. Capen) 12. 06:25 PM - Re: Antenna doubler plate - prime or not (Robert L. Nuckolls, III) 13. 06:50 PM - Re: Antenna doubler plate - prime or not (Ralph E. Capen) 14. 07:12 PM - Re: Regulator trouble? (Ed) 15. 07:42 PM - Re: [ExperimentalAvionics] Antenna doubler plate - prime or not (Wayne Sweet) 16. 07:42 PM - Re: Antenna doubler plate - prime or not (Greg Young) 17. 08:07 PM - Lightspeed/EIS (Allan Aaron) 18. 08:20 PM - Re: Regulator trouble? (Prue Motorgliders) ________________________________ Message 1 _____________________________________ Time: 06:40:32 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Marker beacon antenna for composite At 09:40 AM 6/16/2007 -0800, you wrote: >I have a spare copper tape dipole nav antenna installed in my wing. Will >this work for a MB antenna instead? Might. Give it a try. It's a LONG way from optimal but the MB signal is so strong that depending on the sensitivity of your receiver, it may be good enough. Bob . . . ________________________________ Message 2 _____________________________________ Time: 06:41:40 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: re: MB antennnas At 09:35 PM 6/15/2007 -0400, you wrote: > >Thanks Bob, >Not only is that $$$, it looks like it will cost you about 3 knots. I'll >take it upon myself to write down the dimensions and post next time I >see one. Looks darn simple. With the Lancair Legacy I am trying to keep >all of the antennas indoors. > >Glenn Hmmmm . . . during the course of this thread I've been remiss in not pointing out that the inside antennas work only in fiberglas composite structures . . . the carbon fiber airplanes offer too much attenuation. Bob . . . ________________________________ Message 3 _____________________________________ Time: 06:50:00 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: RE: Marker beacon antenna for composite aircraft At 09:28 PM 6/15/2007 -0400, you wrote: > >40" of 22AWG wire it shall be. Any special needs for attaching it to the >coax? Solder? Duct tape? Insulate? I will be coming back from under the >panel. Ok if I epoxy (tack) the wire to the body so it does not move? > >Thanks for the tip Solder is recommended. You're laying against a non-conductive surface (assuming fiberglas . . . this won't work in a carbon structure) so no other insulation is needed. Tape or otherwise fasten the wire to the inside surface to keep it stretched out. Both ends and a couple of places along the length is sufficient. Bob . . . ________________________________ Message 4 _____________________________________ Time: 06:50:00 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: You need to do this yourself at: http://www.matronics.com/subscription/ At 04:49 PM 6/15/2007 -0600, you wrote: >please take off the mail list >Jim Ernst ________________________________ Message 5 _____________________________________ Time: 06:55:43 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Stupid question I'm sure At 04:53 PM 6/15/2007 -0400, you wrote: > > >Ok, so in a composite airplane. As it relates to the Radio Stack. The >Radios, Audio panel, etc are mounted in an aluminum chassis, and some of the >items have "shield" that go to the outer tabs on the radios, etc. Not sure what "shields" you're referring to or what the "outer tabs" are. > So do I >need to take a ground from the radio rack chassis to the single point ground >of the rest of the airplane? Or do those "Shields" end up being grounded >back thru the ground wires to the radios themselves? Assuming you're talking about enclosure components of the radios and not wiring, you will find that most if not all of your radios take the power (-) lead to the chassis internally. By the time all the radios get power grounded to the single point ground, the "stack" is pretty well tied down by multiple conductors. Additional wires from the stack structure to ground will not add value. As for the shields on wires. Wire per the wiring diagrams/ instructions for each radio. Bob . . . ________________________________ Message 6 _____________________________________ Time: 06:55:43 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: re: MB antennnas At 12:21 PM 6/15/2007 -0700, you wrote: > >I have a "sled runner" on the bottom of my "RV Trainer" aka Grumman AA1B >that is no longer connected to anything. I am about to remove it. Does >anyone want it? I don't need the antenna . . . but if you could get me the dimensions I asked about earlier, it would be helpful. Bob . . . ________________________________ Message 7 _____________________________________ Time: 08:01:07 AM PST US From: "Alan Adamson" Subject: RE: AeroElectric-List: Stupid question I'm sure Bob, Thanks for the comments. To be a little clearer. I'm specifically wondering about the shields on shielded wires that connect to the radios. For example on the Garmin sl30, there are shields on wires that connect the sl30 to the audio panel and those shields are attached (only terminated on the radio side) to a metal extension plate that is physically attached to the back of the sl30's mounting tray, which should also attach it to the "chassis" of the sl30. It is also my understanding that it most modern electronics, the manufacture isolates the "chassis" from the internal power ground to prevent any form of "short" that may harm a human. If this is the case, then those shields would not have a path to ground thru the chassis to the power ground. Perhaps this assumption is incorrect. I suppose I could tell by taking an ohm reading off the ground lead to the chassis for example. If they are somehow connected, I should see a dead short correct? In a metal airplane, this probably isn't as much of an issue as the radio stack would most likely be chassis grounded thru the metal structure of the airframe, but in composites, on in a composite panel, you don't have that benefit and so I was curious if a separate ground wire should ground the radio chassis to the single point ground? Thanks, Alan -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Sunday, June 17, 2007 10:55 AM Subject: Re: AeroElectric-List: Stupid question I'm sure --> At 04:53 PM 6/15/2007 -0400, you wrote: > > >Ok, so in a composite airplane. As it relates to the Radio Stack. The >Radios, Audio panel, etc are mounted in an aluminum chassis, and some >of the items have "shield" that go to the outer tabs on the radios, etc. Not sure what "shields" you're referring to or what the "outer tabs" are. > So do I >need to take a ground from the radio rack chassis to the single point >ground of the rest of the airplane? Or do those "Shields" end up being >grounded back thru the ground wires to the radios themselves? Assuming you're talking about enclosure components of the radios and not wiring, you will find that most if not all of your radios take the power (-) lead to the chassis internally. By the time all the radios get power grounded to the single point ground, the "stack" is pretty well tied down by multiple conductors. Additional wires from the stack structure to ground will not add value. As for the shields on wires. Wire per the wiring diagrams/ instructions for each radio. Bob . . . ________________________________ Message 8 _____________________________________ Time: 08:09:13 AM PST US From: "Robert Feldtman" Subject: Re: AeroElectric-List: Stupid question I'm sure I'd say you can't have too many grounds! the central point is key. You must be refering to the coaxial cable outer conductor (shield).... my question is should we pop a ferrite bead RF surpressor around the power and/or audio cable bundles out of the back of the radio to help ignintion noise surpression? bobf W5RF On 6/17/07, Robert L. Nuckolls, III wrote: > > nuckollsr@cox.net> > > At 04:53 PM 6/15/2007 -0400, you wrote: > > > > > > >Ok, so in a composite airplane. As it relates to the Radio Stack. The > >Radios, Audio panel, etc are mounted in an aluminum chassis, and some of > the > >items have "shield" that go to the outer tabs on the radios, etc. > > Not sure what "shields" you're referring to or what the "outer tabs" > are. > > > So do I > >need to take a ground from the radio rack chassis to the single point > ground > >of the rest of the airplane? Or do those "Shields" end up being grounded > >back thru the ground wires to the radios themselves? > > Assuming you're talking about enclosure components > of the radios and not wiring, you will find that most > if not all of your radios take the power (-) lead to > the chassis internally. By the time all the radios > get power grounded to the single point ground, the "stack" > is pretty well tied down by multiple conductors. Additional > wires from the stack structure to ground will not add > value. > > As for the shields on wires. Wire per the wiring diagrams/ > instructions for each radio. > > Bob . . . > > ________________________________ Message 9 _____________________________________ Time: 08:13:39 AM PST US From: "Bob McCallum" Subject: Re: AeroElectric-List: re: MB antennnas Hi Bob; Not trying to be a "smart ass" but in the light of accuracy, not ONLY fibreglass, but also wood structures such as the F8L Falco where internal antennas are used to good advantage. (and possibly other non-conductive constructions as well). Bob McC ----- Original Message ----- From: "Robert L. Nuckolls, III" Sent: Sunday, June 17, 2007 10:42 AM Subject: RE: AeroElectric-List: re: MB antennnas > > Hmmmm . . . during the course of this thread I've > been remiss in not pointing out that the inside antennas > work only in fiberglas composite structures . . . the carbon > fiber airplanes offer too much attenuation. > > Bob . . . ________________________________ Message 10 ____________________________________ Time: 09:40:37 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: re: MB antennnas At 11:08 AM 6/17/2007 -0400, you wrote: >Hi Bob; > >Not trying to be a "smart ass" but in the light of accuracy, not ONLY >fibreglass, but also wood structures such as the F8L Falco where internal >antennas are used to good advantage. (and possibly other non-conductive >constructions as well). > >Bob McC Point well taken. Let's refine the idea as limited to non-conductive composites. Some folks have even reported "satisfactory" performance from antennas contained within a tube and fabric tailcone. I'm a bit skeptical as to the quantification of "satisfactory" . . . Bottom line is try it an see if it meets your needs knowing that carbon fiber composites are have yielded unsatisfactory results in a number of repeated experiments. Bob . . . ________________________________ Message 11 ____________________________________ Time: 05:59:02 PM PST US From: "Ralph E. Capen" Subject: AeroElectric-List: Antenna doubler plate - prime or not Fellow tron chasers, I'm putting a comant bent whip on the underside of my RV6A. I have a good doubler plate (derived from the AC43.13) - pictures if anyone wants to see. My question is should I prime it? My initial thoughts are that the existence of the metal structure will provide the ground plane even if it is not bonded electrically to the structure - meaning prime on...... Otherwise, how is bonding effected as there is a cork gasket that is to be installed? Do the four antenna mounting screws provide sufficient bonding? Thanks, Ralph ________________________________ Message 12 ____________________________________ Time: 06:25:55 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Antenna doubler plate - prime or not At 08:55 PM 6/17/2007 -0400, you wrote: > > >Fellow tron chasers, > >I'm putting a comant bent whip on the underside of my RV6A. I have a good >doubler plate (derived from the AC43.13) - pictures if anyone wants to see. >My question is should I prime it? > >My initial thoughts are that the existence of the metal structure will >provide the ground plane even if it is not bonded electrically to the >structure - meaning prime on...... >Otherwise, how is bonding effected as there is a cork gasket that is to be >installed? Do the four antenna mounting screws provide sufficient bonding? If it were my airplane . . . prime the doubler and rivet to the skin and closest handy structural components of the fuselage. Drill rivet holes after priming. A rivet driven into a properly sized hole swells up and becomes a gas-tight joint for bringing the skin and the doubler together electrically. Before riveting the doubler in, Cleco into place and put a hole pattern in both doubler and skin to accommodate the antenna. Refer to the figure at: http://www.aeroelectric.com/Pictures/Antenna/Antenna_Installation.gif De-mount the doubler and clean the aluminum round all the antenna screw holes on both sides of both skin and doubler. Now rivet the doubler in . . . Leave cork gasket out. Run 1/8" bead of RTV around outside edge of antenna base flange before pressing to the skin and installing screws. Torque antenna mounting screws to recommended limits. If the kit doesn't come with all metal lock nuts, then substitute them. Measure torque on lock nut as you're driving it down and increase final torque value by that same amount for final seating of the nuts. This technique strives for permanent, gas-tight joints at all antenna mounting holes. Bob . . . ________________________________ Message 13 ____________________________________ Time: 06:50:51 PM PST US From: "Ralph E. Capen" Subject: Re: AeroElectric-List: Antenna doubler plate - prime or not Excellent! I already had the hole patterns done - and the drilling/dimpling. I'll chase it through once with a drill bit through each rivet hole to accomplish your suggestion for each rivet - in addition to cleaning all of the screw holes. I already have nutplates for the attachment - I think I have the correct torque values in my hangar. I didn't like the way the cork gasket looked anyway......RTV rocks! Thanks Bob! Ralph ----- Original Message ----- From: "Robert L. Nuckolls, III" Sent: Sunday, June 17, 2007 10:23 PM Subject: Re: AeroElectric-List: Antenna doubler plate - prime or not > > > At 08:55 PM 6/17/2007 -0400, you wrote: > >> >> >>Fellow tron chasers, >> >>I'm putting a comant bent whip on the underside of my RV6A. I have a good >>doubler plate (derived from the AC43.13) - pictures if anyone wants to >>see. >>My question is should I prime it? >> >>My initial thoughts are that the existence of the metal structure will >>provide the ground plane even if it is not bonded electrically to the >>structure - meaning prime on...... >>Otherwise, how is bonding effected as there is a cork gasket that is to be >>installed? Do the four antenna mounting screws provide sufficient >>bonding? > > If it were my airplane . . . prime the doubler and rivet to > the skin and closest handy structural components of the > fuselage. Drill rivet holes after priming. A rivet driven into > a properly sized hole swells up and becomes a gas-tight joint > for bringing the skin and the doubler together electrically. > > Before riveting the doubler in, Cleco into place and put > a hole pattern in both doubler and skin to accommodate the > antenna. > > Refer to the figure at: > > http://www.aeroelectric.com/Pictures/Antenna/Antenna_Installation.gif > > De-mount the doubler and clean the aluminum round all > the antenna screw holes on both sides of both skin > and doubler. > > Now rivet the doubler in . . . > > Leave cork gasket out. Run 1/8" bead of RTV around outside > edge of antenna base flange before pressing to the skin and > installing screws. Torque antenna mounting screws to recommended > limits. If the kit doesn't come with all metal lock nuts, then > substitute them. Measure torque on lock nut as you're driving > it down and increase final torque value by that same amount > for final seating of the nuts. > > This technique strives for permanent, gas-tight joints > at all antenna mounting holes. > > Bob . . . > > > ________________________________ Message 14 ____________________________________ Time: 07:12:46 PM PST US From: Ed Subject: Re: AeroElectric-List: Regulator trouble? I've got more info now, but I'm not sure what it means. I wired up a jack as per Bob's suggestion and can read field voltage on the VOM in flight. I also changed the setpoint on the regulator by about 1 turn on the adjustment screw. The downloaded installation instructions said that should be about 2 tenths of a volt. It had been running about 14.6. The regulator turns out to be an LR3B-14 not the C model I reported previously. I don't know how much difference that makes. When started, the voltage ran right at 14.4, exactly as expected after the adjustment. The field was about 3.5 to 4.5 volts at idle. I'm using a digital VOM because it's what I have, so it jumps around a bit. With strobe, landing/taxi and position lights on and at idle, the buss came down to about 14.1 and the field rose to about 7 or 8 volts. Load was around 17 amps by my meter. In flight the numbers were pretty similar except that the buss never fell much below 14.4 no matter what I did with the lights. The field ran somewhere in the 4ish range with no lights and around 8 with. After about 30 minutes of flying, the buss was at 14.5. When I taxied in, it was 14.7 at idle which I don't understand at all. The field breaker did not blow today. I'm in watch and wait mode for now. Pax, Ed Holyoke Ed wrote: > > The regulator has been in service for about 900 hrs. It's been through > at least 2 or 3 Van's alternators in that time, though I don't have > good records on that. I'll swing by radio shack and check back at a > later date with field voltage info. > > Thanks, > > Ed > > Robert L. Nuckolls, III wrote: > >> >> >> At 09:31 PM 6/13/2007 -0800, you wrote: >> >>> >>> Howdy, >>> >>> The other day, the low volt light started flashing and I found the >>> field breaker popped. This is an LR3C with the notorious Van's 35 >>> amp alternator. I reset the breaker and about 5 minutes later, it >>> popped again. The voltage had been running about 14.6 which seemed a >>> little much so I reset it and turned on some lights. The voltage ran >>> about 13.9 to 14 and the breaker didn't pop for quite a while. About >>> the time I thought that it was cool, the low volt light came on >>> again, but this time the breaker wasn't out. I turned off the master >>> and flew another hour and a half, including a stop for gas, and >>> landed at Aurora. I found a bit of hangar space and pulled the >>> alternator. It had a lot of end play and tested bad at the local >>> auto parts place. I bought another one at Van's - they tried to talk >>> me out of it, but I didn't want to rewire the airplane for the >>> internally regulated unit a long way from home. Hey, I would have >>> happily spent the extra for the B&C alternator, but I was in Aurora >>> not Wichita. >>> >>> It charges just fine, in fact it'll hold voltage at idle with lights >>> on which is more than the old one would do. It is also running at >>> about 14.5 or .6 and the breaker has popped 3 times so far. >> >> >> >> You need to conduct and investigation of system performance >> as outlined in note 8 of >> >> http://aeroelectric.com/articles/Rev11/AppZ_R11J.pdf >> >> and take some readings. In fact, get an el-cheapo analog >> voltmeter for observing field voltage. It's more important >> to know how stable it is than to know the exact voltage reading. >> >> >> >>> The breaker resets and the alternator runs fine for a while, but >>> I'm wondering if I'll blow up the new alternator, too. >> >> >> >> No, I cannot think of any abuse (other than lack of cooling) >> that you could heap on an externally regulated alternator >> from outside that would place it at risk for premature failure. >> >>> Do you think that the regulator is a bit wonky? Is the voltage too >>> high? Am I frying my battery? Is the overvoltage module overactive? >> >> >> >> About 150 years ago Lord Kelvin admonished us, ""If >> you can not measure it, you can not improve it." To >> craft considered answers to your questions, we'll need >> some numbers and some observations of behavior. I'll >> suggest that you craft the field voltage monitoring >> feature suggested in Figure Z-23. >> >> We need to know what the field voltage is in cruise >> RPM with minimum loads and with everything turned on. >> Also make note of voltage fluctuations during what >> should be a steady state condition (turn strobes on/off >> to see how much they added to any wiggles you observe). >> In particular, we'd like to capture field voltage >> behaviors leading up to a trip of the OV protection >> system. >> >> I know this can be tedious and difficult. This is >> why I own data acquisition systems that monitor and >> record real time values. If I had cash for all the >> Jet-A I've burned up waiting to capture a transient >> event in a sneaky failure I could pay off my mortgage. >> >> You're not frying anything. The bus voltage is >> not too high. It's unlikely that the OV protection >> system has become hyper-active with age. You don't >> say how long this regulator has been in service. >> >> Bob . . . >> >> >> >> >> >> > > ________________________________ Message 15 ____________________________________ Time: 07:42:03 PM PST US From: "Wayne Sweet" Subject: AeroElectric-List: Re: [ExperimentalAvionics] Antenna doubler plate - prime or not Do not use the cork gasket. Use RTV around the antenna base AFTER installation. Also, the doubler will need to be riveted, and if solid rivets (not blind rivets) are used, the doulber will be have a solid connection to the aircraft skin. Wayne ----- Original Message ----- From: "Ralph E. Capen" Sent: Sunday, June 17, 2007 5:55 PM Subject: [ExperimentalAvionics] Antenna doubler plate - prime or not > Fellow tron chasers, > > I'm putting a comant bent whip on the underside of my RV6A. I have a good > doubler plate (derived from the AC43.13) - pictures if anyone wants to > see. > My question is should I prime it? > > My initial thoughts are that the existence of the metal structure will > provide the ground plane even if it is not bonded electrically to the > structure - meaning prime on...... > Otherwise, how is bonding effected as there is a cork gasket that is to be > installed? Do the four antenna mounting screws provide sufficient > bonding? > > Thanks, > Ralph > > > Yahoo! Groups Links > > <*> To visit your group on the web, go to: > http://groups.yahoo.com/group/ExperimentalAvionics/ > > <*> Your email settings: > Individual Email | Traditional > > <*> To change settings online go to: > http://groups.yahoo.com/group/ExperimentalAvionics/join > (Yahoo! ID required) > > <*> To change settings via email: > mailto:ExperimentalAvionics-digest@yahoogroups.com > mailto:ExperimentalAvionics-fullfeatured@yahoogroups.com > > <*> To unsubscribe from this group, send an email to: > ExperimentalAvionics-unsubscribe@yahoogroups.com > > <*> Your use of Yahoo! Groups is subject to: > http://docs.yahoo.com/info/terms/ > > ________________________________ Message 16 ____________________________________ Time: 07:42:03 PM PST US From: "Greg Young" Subject: RE: AeroElectric-List: Antenna doubler plate - prime or not You might consider using a paintable sealant rather than RTV. Regards, Greg Young > > I didn't like the way the cork gasket looked anyway......RTV rocks! > > Thanks Bob! > > Ralph > ________________________________ Message 17 ____________________________________ Time: 08:07:39 PM PST US Subject: AeroElectric-List: Lightspeed/EIS From: "Allan Aaron" Hi all I started my engine first time last weekend. All good except the Manifold Pressure and Ignition Timing readouts from the lightspeed plasma 3 box to my EIS4000 were goofy. I get a reading but its obviously not reality. I asked Sandy at GRT and she said that I can't get MP from the lightspeed onto the EIS. But I do get a readout so wonder why I can't just calibrate it using the right SF and OfsetF? The lightspeed manual says the unit outputs 0.01 Volts per inch Hg (MP) and 0.01 Volts per degree (ignition advance). Has anyone hooked up their EIS direct to the lightspeed unit? I know I can buy a separate "microvolt meter" from Lightspeed but don't want to do that. I've emailed Klaus at lightspeed to see whether he knows if the EIS is compatible but received no reply after a week. Just want to confirm it can't be done (and understand why) before I order a separate manifold pressure sensor from Sandy. Thanks again for your collective advice. Allan ________________________________ Message 18 ____________________________________ Time: 08:20:32 PM PST US From: Prue Motorgliders Subject: Re: AeroElectric-List: Regulator trouble? Gee Ed, I have no idea. The only thought I have is to check in with B&C regarding the difference between Mod B and C. That and a description of your history may lead to a understanding. Hopefully the AeroElectric list will have some ideas Jerry On Jun 17, 2007, at 20:09, Ed wrote: > > I've got more info now, but I'm not sure what it means. I wired up a > jack as per Bob's suggestion and can read field voltage on the VOM in > flight. I also changed the setpoint on the regulator by about 1 turn > on the adjustment screw. The downloaded installation instructions said > that should be about 2 tenths of a volt. It had been running about > 14.6. The regulator turns out to be an LR3B-14 not the C model I > reported previously. I don't know how much difference that makes. > > When started, the voltage ran right at 14.4, exactly as expected after > the adjustment. The field was about 3.5 to 4.5 volts at idle. I'm > using a digital VOM because it's what I have, so it jumps around a > bit. With strobe, landing/taxi and position lights on and at idle, the > buss came down to about 14.1 and the field rose to about 7 or 8 volts. > Load was around 17 amps by my meter. > > In flight the numbers were pretty similar except that the buss never > fell much below 14.4 no matter what I did with the lights. The field > ran somewhere in the 4ish range with no lights and around 8 with. > After about 30 minutes of flying, the buss was at 14.5. When I taxied > in, it was 14.7 at idle which I don't understand at all. The field > breaker did not blow today. > > I'm in watch and wait mode for now. > > Pax, > > Ed Holyoke > > Ed wrote: > >> >> The regulator has been in service for about 900 hrs. It's been >> through at least 2 or 3 Van's alternators in that time, though I >> don't have good records on that. I'll swing by radio shack and check >> back at a later date with field voltage info. >> >> Thanks, >> >> Ed >> >> Robert L. Nuckolls, III wrote: >> >>> >>> >>> At 09:31 PM 6/13/2007 -0800, you wrote: >>> >>>> >>>> Howdy, >>>> >>>> The other day, the low volt light started flashing and I found the >>>> field breaker popped. This is an LR3C with the notorious Van's 35 >>>> amp alternator. I reset the breaker and about 5 minutes later, it >>>> popped again. The voltage had been running about 14.6 which seemed >>>> a little much so I reset it and turned on some lights. The voltage >>>> ran about 13.9 to 14 and the breaker didn't pop for quite a while. >>>> About the time I thought that it was cool, the low volt light came >>>> on again, but this time the breaker wasn't out. I turned off the >>>> master and flew another hour and a half, including a stop for gas, >>>> and landed at Aurora. I found a bit of hangar space and pulled the >>>> alternator. It had a lot of end play and tested bad at the local >>>> auto parts place. I bought another one at Van's - they tried to >>>> talk me out of it, but I didn't want to rewire the airplane for the >>>> internally regulated unit a long way from home. Hey, I would have >>>> happily spent the extra for the B&C alternator, but I was in Aurora >>>> not Wichita. >>>> >>>> It charges just fine, in fact it'll hold voltage at idle with >>>> lights on which is more than the old one would do. It is also >>>> running at about 14.5 or .6 and the breaker has popped 3 times so >>>> far. >>> >>> >>> >>> You need to conduct and investigation of system performance >>> as outlined in note 8 of >>> >>> http://aeroelectric.com/articles/Rev11/AppZ_R11J.pdf >>> >>> and take some readings. In fact, get an el-cheapo analog >>> voltmeter for observing field voltage. It's more important >>> to know how stable it is than to know the exact voltage reading. >>> >>> >>> >>>> The breaker resets and the alternator runs fine for a while, but >>>> I'm wondering if I'll blow up the new alternator, too. >>> >>> >>> >>> No, I cannot think of any abuse (other than lack of cooling) >>> that you could heap on an externally regulated alternator >>> from outside that would place it at risk for premature failure. >>> >>>> Do you think that the regulator is a bit wonky? Is the voltage too >>>> high? Am I frying my battery? Is the overvoltage module overactive? >>> >>> >>> >>> About 150 years ago Lord Kelvin admonished us, ""If >>> you can not measure it, you can not improve it." To >>> craft considered answers to your questions, we'll need >>> some numbers and some observations of behavior. I'll >>> suggest that you craft the field voltage monitoring >>> feature suggested in Figure Z-23. >>> >>> We need to know what the field voltage is in cruise >>> RPM with minimum loads and with everything turned on. >>> Also make note of voltage fluctuations during what >>> should be a steady state condition (turn strobes on/off >>> to see how much they added to any wiggles you observe). >>> In particular, we'd like to capture field voltage >>> behaviors leading up to a trip of the OV protection >>> system. >>> >>> I know this can be tedious and difficult. This is >>> why I own data acquisition systems that monitor and >>> record real time values. If I had cash for all the >>> Jet-A I've burned up waiting to capture a transient >>> event in a sneaky failure I could pay off my mortgage. >>> >>> You're not frying anything. The bus voltage is >>> not too high. It's unlikely that the OV protection >>> system has become hyper-active with age. You don't >>> say how long this regulator has been in service. >>> >>> 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.