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AeroElectric-Archive.digest.vol-ci August 11, 2003 - August 20, 2003of these same neat, new ideas will NEVER find their wayonto a certifies ship.So, in the narrow context of defining 'quality' asevolving toward the lowest cost aircraft freeof mechanically-induced accidents, I'll suggest thatthe finest (highest quality?) aircraft to haveever flown are being built in basements and garages.The only thing certified aviation has over us isthe communications system presently mandated by thecertification procedures. I'd bet that fewer than10% of all OBAM aircraft builders fully utilizethe Internet for idea sharing. Sadly, this meansthat most builders will not experience the advantagesyou all enjoy here and on other list-servers.It also means that some are likely to experience sweat-generating events. The bright side is that there areplenty of FARs and dark-n-stormy-night stories totap for information.
At least their airplanes willbe no worst than a C-172, which really isn't allthat bad. I've got a lot of hours in C-172sand I don't walk up to one of them with any senseof trepidation.For those OBAM aircraft builders who chose to gothe extra mile in discovering, trying, filteringand sharing ideas. I'll avoid the the word'quality' but enthusiastically argue that yourairplanes are better than certified.Bob.Subject:From:Bruce Uvanni Date:Aug 11, 2003JBON5L8FGD June 13, 2003) at 12:44:37I have an SD8 backup alternator wired up as shown in Bob'sall electric on a budget. I'm flying now but don't know how totest the SD8 to see if it is working. I also have an E.I. AMP/Voltmeter installed with both alternators wired thourgh a switch to theamp meter.Thanks.BRUCE UVANNIBUVANNI(at)US.IBM.COMDate:Aug 11, 2003From:'Robert L. Nuckolls, III' Subject:Re: Ground LoopsBob & List:During a recent addition of an RST audio panel, an ARC ADF, and a 2ndcomm (UPSAT SL30) to our stock '68 C177 I have had my share ofelectronic gremlins haunting the job.
One is alternator noise and theother is the beacon noise.The alternator was changed 4 years ago and the noise was not aspronounced in the comm 1 radio (KX170B) before the installation as it isnow. I added a 25yr old Radio Shack 5mfd, 60amp, 50Vdc line filter inseries with the alternator A+ but no change. I'm wondering if Iinstalled the device correctly. It is a 3' steel tube about the diameterof a quarter. On each end there is an insulated threaded terminal.
Theprinting on the filter includes a RS stock number an arrow and theelectrical values. The mounting lug is the local ground for the device.I first connected the device with the arrow pointing away from thealternator and the alt noise was unchanged. So I reversed the connection(arrow pointing to the alt) and the noise is the same. I'm wonderingwhich direction is correct and if the filter is in fact functioning.Any filter you put on the back of the alternator willhave a beneficial effect ONLY on ADF and/or LORAN reception.These are effective in the low frequency radio ranges and haveno benefits for AUDIO rate noises (ripple voltage) that isbuilt in to every alternator.I have done the obvious things such as fat wire separation and shieldsconnected only at the source of the noise but now I'm lost.I get a lot of requests like this. It's got to be frustratingto the well intentioned owner/builder who is trying to understandand fix the problem himself.
It's frustrating for me tofigure out a way to describe the full range of troubleshootingtechniques and tools in a few paragraphs of a list-serverinquiry. Tell you what, order my book. If the chapter onnoise mitigation doesn't help you identify and breakthe chain of victim-propagation-source links, I'll refundyour money.Regarding the beacon noise, is there a filter which I can use (make) totame this annoyance.
Because it pulses, it really is an antagonisticlittle devil after several hours flying.Try running the strobe from a pair of 6v lantern batterieslocated right at the power supply and see if you stillhear the noise. If so, then a filter installed right at thepower supply will help.I'd try a S251D479 capacitor from B&C which you can buyatA local parts store might be able to supply you witha computer grade, electrolytic with 10,000 uf or more,16v or more. Wire it right across the power inputleads to the strobe power supply. This will probablyreduce the noise and maybe eliminate it. At worst,we may have to consider adding some filter inductancein series with the strobe supply too.If the lantern battery experiment doesn't show thatnoise is getting onto the system via the 14v supply,it's a whole new ball game.
But one step at a time.Bob.From:'Ron Raby' Subject:AlternatorDate:Aug 11, 2003BobI have a kelly aerospace 70 amp alternator with two field connections F1 andF2. I also have the B&C alternator controllers. My question is what do I dowith the second field connection? Do I run them both to terminal # 4 on theB&C?ThanksRon RabyLancair ESFrom:'James Foerster' Subject:Switches vs relays for lights, strobesDate:Aug 11, 2003Bob,I'm designing details of my panel. I have chosen to use switches for the 8 amplanding lights-two 50 watt auto units,for the taxi lights which draw 8 amps,and for the navigation lights which draw less.
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I could use small relays, butthen the parts count goes up. For the strobe, mounted behind the rear seat, I'mnot so sure. A relay would keep some of the noise from the power leads outof the panel, but I doubt that the power lead is the source of much noise anyway.I can size the wire for allowable voltage loss. What do you think? Switchesfor everything?Jim Foerster J400, panel on the mockup on the bench.Date:Aug 11, 2003From:Charles Brame Subject:Shielding EI WiresMy Jeff Rose EI system came with an installed shielded wire to connectto the battery bus via an ignition switch.
The shielded wire is groundedat the ignition module side and the center wire will obviously connectto the ignition switch. My question is: should the wire from the switchto the battery bus also be shielded? If so, where should it be grounded?Charlie BrameRV-6A N11CBSan AntonioDate:Aug 11, 2003From:'Robert L. Nuckolls, III' Subject:Re: AlternatorBobI have a kelly aerospace 70 amp alternator with two field connections F1 andF2.
I also have the B&C alternator controllers. My question is what do I dowith the second field connection? Do I run them both to terminal # 4 on theB&C?These are terminals for both brushes. You can ground one locally tothe case of the alternator. Or take it back to pin 7 (ground)on the regulator. If you can't find a screw handy on back of alternatorfor grounding extra field connection, perhaps the least problematicalapproach is to run the extra wire back to regulator.Bob.From:'Tinne maha' Subject:Re: RG58 Coax article I promisedDate:Aug 11, 2003Bob,Once again I feel eternally grateful for this educaitonal service youprovide! Not only have you cleared up my suspicions answered my questionsbut given me better options too.
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Knowing it is core to homebuilding (and Ifeel it should becore to living)I take full responsibility for any all ofmy actions whether they be from knowledge gained here or elsewhere.I doubt that I alone am enough interest for you but I would love topurchase an 'LSE re-hab' kit consisting of the twisted pair shielded wireswith BNC connectors installed on one end and a separate15 pin D-subconnector (it is female) for the controller input. I completely understandif you would rather just sell me the wires connectors. Please let me knowthe amount where to send a check.I can do the kit for $50. How long do you want the coil cablesto be? My mailing address is 6936 Bainbridge, Wichita, KS 67226Bob,I just dropped the check in the mail (really)along with a note specifying addressphone number.
38' length please. Thank you tons for that!Would you mind clearing up another cloud in my mind? Per my kit manufacturer'sinstructions I connectedmy bonding strap toan engine mount bolt (tube fabricfuselage) but then I saw BC's instructions/advice not to include the engine mountin the ground cirquit.
Why not?BC recommends mounting the bonding strap to the ground bus brass bolt that goesthrough an all metal firewall. That firewall is also connected to the enginemount, so doesn't that include it in the ground cirquit?Not sure yet if it applies here or not, but, by far, the most frustrating partof building my aircraft is getting contrary opinions from sources I assume tobe much more qualified than I. The good side, ofcourse, is that it forces me tosearch for a deeper understanding but that process is very time consuming frustrating.With Bob as the backbone, this list makes the electrical part of thatprocess much easier to deal with.GrantDate:Aug 11, 2003From:'Robert L.
Nuckolls, III' Subject:Re:I have an SD8 backup alternator wired up as shown in Bob'sall electric on a budget. I'm flying now but don't know how totest the SD8 to see if it is working. I also have an E.I. AMP/Voltmeter installed with both alternators wired thourgh a switch to theamp meter.Turn main alternator off, turn aux alternator on. Reduceoperating loads to a minimum. Run engine up to at least2000 rpm.
Bus voltage should be something above 13.8 voltsand switching your amp meter to the Aux Alternator readoutshould show some amount of output current.You won't be able to fully load this alternator untilyou can operate at cruise RPMs. In this configuration,you should be able to increase system loads untilalternator output is on the order of 10A withouthaving the bus votlage drop below 13.0 volts.Bob.Date:Aug 11, 2003From:'Robert L. Nuckolls, III' Subject:Re: Switches vs relays for lights, strobesBob,I'm designing details of my panel. I have chosen to use switches for the8 amp landing lights-two 50 watt auto units,for the taxi lights which draw8 amps, and for the navigation lights which draw less.
I could use smallrelays, but then the parts count goes up. For the strobe, mounted behindthe rear seat, I'm not so sure. A relay would keep some of the noise fromthe power leads out of the panel, but I doubt that the power lead is thesource of much noise anyway. I can size the wire for allowable voltageloss.
What do you think? Switches for everything?I don't understand your question.
Are the switches of choiceso small that there is a question as to suitability for thesehigher loads?I don't see a need for adding relay-buffering to a switchedcircuit unless your switches are way undersized. For whatit's worth, saw a tandem-wing airplane last year at theField of Dreams Fly-in, Coffey Co. Airport with miniaturetoggle switches for everything.
Including 55W landinglight, nav lights and magnetos. He reported good service fromthese switches for over 3 years.What kind of switches are you contemplating?Bob.Date:Aug 11, 2003From:'Robert L. Nuckolls, III' Subject:Re: Shielding EI WiresMy Jeff Rose EI system came with an installed shielded wire to connectto the battery bus via an ignition switch. The shielded wire is groundedat the ignition module side and the center wire will obviously connectto the ignition switch. My question is: should the wire from the switchto the battery bus also be shielded? If so, where should it be grounded?I wouldn't worry about it.
Ordinary wire should be justfine for the power path. If it DOES have noise on it, it willbe CURRENT noise that radiates out of a shield as if it wasn'teven there.Bob.From:'Ernest Kells' Subject:Re: Part 91Date:Aug 11, 2003Jim and Others:In the following interchange there is an issue associated with differentcountries.
This is 'not necessarily' a question of Quality -butSTANDARDS. I am a Canadian like the first poster, with a 90+% completeRV-9A. I have built to CDN standards, not US standards -I plan to fly aLOT in the US. I will not have a problem. I followed the Vans Aircraftinstructions - except where they conflict with CDN standards.
For example,the US will say that a rod end bearing is fastened with an AN3-5A nut (whichmust be torqued to standard).Canada says that a bearing in the rod end fastened with the AN3-5A nut willbe held in compression (subject to seizing up north) and must be replacedwith a AN3-3 (drilled bolt and castled nut). It's probably superior - butI'll bet that a coin got flipped in the decision. After all, most standardswere developed during the war where everybody (especially Canada and theCommonwealth, US and Britain) totally shared in the design and manufacturingof aircraft.Although each country requires compliance to its standards for registration,each will respect the other's aircraft in each other's airspace. That's theonly significant fact. A change in registration is slightly morecomplicated.Ernest Kells - RV-9A O235-N2C, Wood Prop90% Complete - Fairings and Intersections 95% complete Cheers, I am interested in the regulations in USA as I expect to visitand tour with my OBAM as a Canadian. I have also tried to build to US and UKrequirements for safety. My understanding was that OBAM aircraft do not havethe standard 'certified' quality, thus permitting experimentationand.
Not trying to start anything here but do you mean to imply that the planes we build implicitly have 'less' quality? I am sure some do and I am sure some don't. Just wondering about the statement. Yes we do have more latitude for experimentation, but that.could. lead to higher or lower quality.
JamesDate:Aug 11, 2003From:Kevin Horton Subject:Re: Part 91Cheers, I am interested in the regulations in USA as expect to visitand tour with my OBAM as a Canadian. I have also tried to build to US and UKrequirements for safety.
My understanding was that OBAM aircraft do not havethe standard 'certified' quality, thus permitting experimentation andvariation. It would appear that Dan Checkoway (at dan(at)rvproject.com) refersto the following:'Powered civil aircraft with standard category U.S.
Is that us?FergEuropa A064Ferg - you shouldn't have any issues with respect to the aircraftwhen flying in the US. You just need to get a Special FlightAuthorization from the FAA. There is a 'blanket' Special FlightAuthorization that you can download and carry with you:The bigger issue is understanding the subtle differences between theops rules in FAR 91 and our CARs.As far as Dan's site, I'm not sure whichpart of the site you are referring to. But homebuilts do not receivea standard category U.S.
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Airworthiness certificate.