---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 04/07/06: 16 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:08 AM - Re: Re: Radios OFF during startup (Brian Lloyd) 2. 08:42 AM - Re: Why use starter contactor? () 3. 08:43 AM - Re: Radios OFF during startup (Robert L. Nuckolls, III) 4. 09:12 AM - Visio symbols (tom) 5. 09:43 AM - Re: Visio symbols (Lloyd, Daniel R.) 6. 11:30 AM - Air Speed Switch (dsvs@comcast.net) 7. 01:01 PM - Re: Visio symbols (Mickey Coggins) 8. 02:51 PM - Re: Re: Why use starter contactor? (John D. Heath) 9. 02:51 PM - Re: Glide Slope Antenna (Richard Dudley) 10. 02:53 PM - Re: Re: Why use starter contactor? (Robert L. Nuckolls, III) 11. 03:02 PM - Re: Radios OFF during startup (Robert L. Nuckolls, III) 12. 03:08 PM - Re: Re: Why use starter contactor? (Robert L. Nuckolls, III) 13. 04:02 PM - Re: Re: Why use starter contactor? (Brian Lloyd) 14. 04:22 PM - Re: Checking out a radio installation (Steven Anderson) 15. 04:41 PM - Re: Re: Why use starter contactor? (Brian Lloyd) 16. 08:01 PM - Re: Re: Why use starter contactor? (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 07:08:11 AM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Re: Radios OFF during startup --> AeroElectric-List message posted by: Brian Lloyd Robert L. Nuckolls, III wrote: > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > At 06:19 PM 4/6/2006 -0500, you wrote: > >> --> AeroElectric-List message posted by: "Dave Morris \"BigD\"" >> Learned] Radios OFF during startup >> >> I guess that would mean that the $150 radio in my car is more robust >> than the $3,500 radio in your airplane? I sure don't have an >> avionics master switch in my car. >> >> Dave Morris > > > Good question. The avionics master switch is still alive > and well in many venues but nobody I've come across can > explain the science or describe the repeatable experiment > that shows why it's 'needed'. Oh, that one is easy Bob. It is convenient. Some aircraft have a LOT of radios. My aztec has an audio panel, a GPS/comm, a nav-com, an RNAV receiver, an ADF, a transponder, an EHSI, a horizontal gyro (separate circuit from the EHSI, and a music radio. It is a pain the butt to turn all those on/off switches. It is much more convenient to have one switch to turn all that stuff on and off. Of course, that one switch can also turn all that stuff off at the same time when I don't want it to. When I did the e-bus in my Comanche 20 years ago I added a second switch that would connect my e-bus (I called it the avionics bus then but it also had the needle-ball on it too) to the backup battery in case the main avionics bus switch failed. (At the time it was a SPDT center-off switch -- yeah, I have learned something since then.) -- Brian Lloyd 361 Catterline Way brian-yak at lloyd dot com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . - Antoine de Saint-Exupery ________________________________ Message 2 _____________________________________ Time: 08:42:09 AM PST US From: Subject: AeroElectric-List: Re: Why use starter contactor? --> AeroElectric-List message posted by: >From: Ken >Subject: Re: Why use starter contactor? >Possibly because the pros and cons of that have been discussed at length >several times here Michael. Several folks related experiences with stuck >on automotive starters when I've brought up the subject. Nevertheless I >went with a 25 amp rated marine key starter switch which I believe is >less likely to cause problems than an additional small relay. A cheap 40 >amp relay is not immune from sticking either in this kind of service. Got >to admit though my key switch will be a bear to change out compared to a >contactor or a small relay when/if it ever fails, and it cost more than >either. >Ken Ken: Thanks for the thoughtful reply. My postulation is if you use a BIG FAT start button and no extra firewall relay/ solenoids/contactors, chance of starter run-on / spontaneous engagement is nil. Has this happened in a car you know of? To the config I suggest in a plane? Your comment about *several folks* who claim they had problems is great, but with out details its like the OV alternator thing, just rumor or irrelevant. There are reasons a starter can run-on. I suspect you are either talking a old Bendix drive starters or OLD firewall Cessna or Piper firewall solenoids, which do stick when they get old. Neither apply to our conversation. People who switched to new starters have got run-ons because the OLD firewall solenoid was retained and stuck; its NOT an issue of the starter itself. This supports my claim that LESS IS MORE. Get rid of that old solenoid and get a big 60 amp start button. I researched this thoroughly. I talked to SkyTec. The chance of sticking starter is next to nothing. I also asked about the no secondary solenoid and guess what? They said its made that way and will work fine. Let's say you did get a run-on, it would be during start, you would shut down. SkyTec shows how to wire a run-on light if you like. Chance of it engaging in flight? never. Skytec has more starters flying than anyone. I think they know what's up. QUOTE: What about the Bendix? Maybe it stuck? **Since Sky-Tec starters do not use mechanical Bendix drives to actuate the starter, this is actually nearly impossible for a Sky-Tec starter to keep itself engaged with the aircraft ring gear. Sky-Tec starters are electromechanically engaged therefore requiring voltage to engage the starter's drive pinion gear with the ring gear. Without voltage, the pinion simply cannot remain in the flywheel. A spring and a helical return will both force the drive pinion back out of the ring gear and into the rest position.** Ref: http://www.skytecair.com/Cessna_Solenoids.htm Cessna (mostly) and Piper, apparently have a history of Firewall Solenoids sticking, so actually even a factory solenoid (relay) can stick. That is WHY I suggest a big OLD fat start button, like a race car. (w/ catch diode of course) All the $60,000-$200,000 Luxury and Sport cars are going to no key push button start switches. Here is some other good info from SkyTec: Troubleshooting Diagram: guide to Gen & spacific (to run on) issues: http://www.skytecair.com/Troubleshooting.htm Here is two wiring diagrams from SkyTec: http://www.skytecair.com/Wiring_diag.htm Here is a guide to wiring, with specifics to starters: http://www.skytecair.com/Wiring_Experimental.pdf To be fair to Bob, if it ain't broke don't fix it. Nothing WRONG with the Z diagram xyz, just suggesting if you want a lean mean electrical system with more than adequate or even superior reliability and safety, while lowering weight and complexity, consider trashing the BIG fw contactor. The next step is get rid of the BIG master contactor. You only need a 30-60 amp relay if you don't run the starter load through it. Cheers George --------------------------------- ________________________________ Message 3 _____________________________________ Time: 08:43:21 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Radios OFF during startup --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:36 PM 4/6/2006 -0700, you wrote: >--> AeroElectric-List message posted by: "B Tomm" > >Is it possible that the radio was somehow affected by a short duration "low" >voltage as the engine drew massive current during start? > >Bevan If that's the real cause, then the device has some serious deficiencies. Here's a piece I did on DO-160 testing some years ago for a builder and updated this morning for posting on my website at: http://www.aeroelectric.com/articles/What's_all_this_DO160_Stuff_Anyhow.pdf See paragraph (c) Bob . . . < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > ________________________________ Message 4 _____________________________________ Time: 09:12:45 AM PST US From: "tom" Subject: AeroElectric-List: Visio symbols --> AeroElectric-List message posted by: "tom" I am using Microsoft Visio for the drawings of my electrical system. While creating the symbols is fairly straightforward, I have not yet discovered how to place the small blue "x" connection points where I need them. The basic shapes come with them, but I need to place them at the end of a line, such as a diode symbol. Also, how are the unneeded ones deleted when the symbol is complete? Any help much appreciated. Tom Barter Kesley, IA Avid Magnum O-320 ________________________________ Message 5 _____________________________________ Time: 09:43:53 AM PST US Subject: RE: AeroElectric-List: Visio symbols From: "Lloyd, Daniel R." --> AeroElectric-List message posted by: "Lloyd, Daniel R." You can take a standard template drawing and modify it by using the un group function and it will become a series of shapes, take one of the templates, ungroup it, copy the item you want and re-group the template and paste the copy into your item. Hope it helps Do not archive Dan RV10 4269 -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of tom Sent: Friday, April 07, 2006 12:10 PM Subject: AeroElectric-List: Visio symbols --> AeroElectric-List message posted by: "tom" I am using Microsoft Visio for the drawings of my electrical system. While creating the symbols is fairly straightforward, I have not yet discovered how to place the small blue "x" connection points where I need them. The basic shapes come with them, but I need to place them at the end of a line, such as a diode symbol. Also, how are the unneeded ones deleted when the symbol is complete? Any help much appreciated. Tom Barter Kesley, IA Avid Magnum O-320 ________________________________ Message 6 _____________________________________ Time: 11:30:22 AM PST US From: dsvs@comcast.net Subject: AeroElectric-List: Air Speed Switch --> AeroElectric-List message posted by: dsvs@comcast.net Bob and Others I need to purchase an airspeed switch that is closed when stationary and opens at roughly 15 knots. An adjustable unit is fine as long as the adjustment point can be set for fairly low (15-20 knot) range. Any idea of a vendor for this device. ACS has only one and the adjustment point is above 80 knots. Thanks in advance. Don ________________________________ Message 7 _____________________________________ Time: 01:01:04 PM PST US From: Mickey Coggins Subject: Re: AeroElectric-List: Visio symbols --> AeroElectric-List message posted by: Mickey Coggins > I am using Microsoft Visio for the drawings of my electrical system. While > creating the symbols is fairly straightforward, I have not yet discovered > how to place the small blue "x" connection points where I need them. The > basic shapes come with them, but I need to place them at the end of a line, > such as a diode symbol. Also, how are the unneeded ones deleted when the > symbol is complete? Any help much appreciated. Hi Tom, I think this article will help you out. http://www.2000trainers.com/printarticle.aspx?articleID=206 -- Mickey Coggins http://www.rv8.ch/ #82007 finishing ________________________________ Message 8 _____________________________________ Time: 02:51:43 PM PST US From: "John D. Heath" Subject: Re: AeroElectric-List: Re: Why use starter contactor? --> AeroElectric-List message posted by: "John D. Heath" TWIMC (Which is probaly only me), (1) Electrial Solenoid engaged starters,as used on Lycoming, Chevrolet,BMW, and Porsche, do stick. (2) Solenoid engaged starters are disengaged by a spring and an over running mechanism in the starter gear. (3) I have personally seen three out of the four named, stick . (4) They stick and continue to crank the engine, they stick and don't crank the engine, and all modes of stick in between. (5) They stick when they are new or old, clean or dirty but mostly they stick because they are misaligned or have not been lubricated. (6) One of these starters that fail in the "CRANK the engine mode" with the +12VDC wired directly to the solenoid has a great big wire as big around as your index finger HOT and you can't turn it off. (7) There are many light weight relays capable of eliminating this problem by attaching the +12VDC first to it and then on to the starter solenoid. No device that controls the starter directly through its solenoid control circuit can do this. (8) I have had multiple experiences with these type failures. Allow me to pass these experiences on to you and eliminate the time and aggravation it would take for you to accumulate them yourself. Use the information as you will. (9) DO NOT ARCHIVE John D. ________________________________ Message 9 _____________________________________ Time: 02:51:43 PM PST US From: Richard Dudley Subject: Re: AeroElectric-List: Glide Slope Antenna --> AeroElectric-List message posted by: Richard Dudley Thanks, Bob. RHDudley Robert L. Nuckolls, III wrote: >--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > >At 04:20 PM 4/5/2006 -0400, you wrote: > > > >>--> AeroElectric-List message posted by: Richard Dudley >> >>Hi Bob, >>Where would I find the GS antenna diagram that is referred to here? >> >> > > The diagram we've been discussing is Figure 13-13 in the > 'Connection. Finding someplace to mount such a beast is the > hard part. I think I'd go for the coupler approach. Or, if > you have a fiberglass airplane, try sticking an 8" piece of wire > into a BNC connector and let it dangle out the back of the > GS receiver. When on the runway centerline, glideslope and > localizer signals are huge. You're looking right down the > "barrel" of a 5w transmitter from a couple miles away max. > A wet string would probably get you a good enough signal. > > > If a compromise antenna doesn't work, go for the coupler > from http://www.chiefaircraft.com and others. Looks > like this: > >http://www.aeroelectric.com/Pictures/Antenna/CI_507.jpg > > I'd much rather install a coupler somewhere than try > to find a 'nice' place to mount a stand-alone GS > antenna. > > Bob . . . > > > > > > > > > > ________________________________ Message 10 ____________________________________ Time: 02:53:09 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Why use starter contactor? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:37 AM 4/7/2006 -0700, you wrote: >--> AeroElectric-List message posted by: > > >From: Ken > >Subject: Re: Why use starter contactor? > > >Possibly because the pros and cons of that have been discussed at > length > >several times here Michael. Several folks related experiences with > stuck > >on automotive starters when I've brought up the subject. > Nevertheless I > >went with a 25 amp rated marine key starter switch which I believe is > >less likely to cause problems than an additional small relay. A > cheap 40 > >amp relay is not immune from sticking either in this kind of > service. Got > >to admit though my key switch will be a bear to change out > compared to a > >contactor or a small relay when/if it ever fails, and it cost more > than > >either. > >Ken > > Ken: > > Thanks for the thoughtful reply. > > My postulation is if you use a BIG FAT start button and no extra > firewall relay/ >solenoids/contactors, chance of starter run-on / spontaneous engagement is >nil. > >Has this happened in a car you know of? To the config I suggest in a plane? > > Your comment about *several folks* who claim they had problems is > great, but >with out details its like the OV alternator thing, just rumor or irrelevant. Wasn't rumor. Had many customers report the phenomenon and we demonstrated it on the bench . . . > > > There are reasons a starter can run-on. I suspect you are either talking a >old Bendix drive starters or OLD firewall Cessna or Piper firewall solenoids, >which do stick when they get old. Neither apply to our conversation. Nope, we were talking about modern PM starters . . . > > People who switched to new starters have got run-ons because the OLD > firewall >solenoid was retained and stuck; its NOT an issue of the starter itself. > > This supports my claim that LESS IS MORE. Get rid of that old solenoid and >get a big 60 amp start button. Not so. "Run on" in the context of PM starters and airplanes had nothing to do with the selection of contactors. Unlike wound-field motors supplied on B&C (and perhaps other) starters, the PM offerings by Skytec (and perhaps others) are efficient GENERATORS of electrical power while the armatures are spinning down. When the pilot releases the starter button after the engine fires, connection between the starter motor and battery was being opened just fine. However, IF the starter was wired for external contactor, voltage being generated by the coasting armature was still applied to the solenoid engagement windings thus keeping the pinion gear engaged for some period of time (perhaps 2-5 seconds) after the button was released. The starter's overrun clutch prevented damage but it was obviously an undesirable operating quality. One fix was to go to Figure Z-22 such that the starter's built in contactor became the primary electrical switching device. The relay allowed any starter switch selected by the builder to stay in place. Adding the relay broke power to the solenoid's hold-coil and effected immediate release of the pinion gear in spite of the armature's spin-down voltage. Another option was described in October of 2004 when this sketch was published on my website: http://www.aeroelectric.com/articles/StarterWiring.pdf Figure 3 suggests using the "I" terminal of the external contactor to exert absolute control over the solenoid's hold coil. Of course, the forth options is Figure 1, a 30A push button and 14AWG wire to replace the relay shown in Z-22 for what has been described as the simplest approach. This approach is also electrically acceptable but offers the least number of options for selection of start switches. The "run-on" or delayed disengagement phenomenon is unique to PM starters and has nothing to do with sticking contactors. > > >I researched this thoroughly. I talked to SkyTec. The chance of sticking >starter >is next to nothing. But not zero . . . > I also asked about the no secondary solenoid and guess >what? They said its made that way and will work fine. Let's say you did get >a run-on, it would be during start, you would shut down. SkyTec shows how >to wire a run-on light if you like. Chance of it engaging in flight? never. > > Skytec has more starters flying than anyone. I think they know what's up. Yup, ask them about sticking contactors and they can accurately report no big problems as will every other starter manufacturer. Ask them about delayed disengagement or run-on of their starters when wired like B&C starters, and they'll confirm what I've stated above. No rumors, hard repeatable experiments. > > > QUOTE: > > What about the Bendix? Maybe it stuck? > >**Since Sky-Tec starters do not use mechanical Bendix drives to actuate the >starter, this is actually nearly impossible for a Sky-Tec starter to keep >itself >engaged with the aircraft ring gear. Sky-Tec starters are >electromechanically >engaged therefore requiring voltage to engage the starter's drive pinion >gear with >the ring gear. Without voltage, the pinion simply cannot remain in the >flywheel. >A spring and a helical return will both force the drive pinion back out of >the ring >gear and into the rest position.** This is true of every brand of starter using direct engagement of the pinion gear by a solenoid that also happens to drive a set of contacts for control of armature current. > > Ref: http://www.skytecair.com/Cessna_Solenoids.htm > > > Cessna (mostly) and Piper, apparently have a history of Firewall Solenoids >sticking, so actually even a factory solenoid (relay) can stick. That is WHY >I suggest a big OLD fat start button, like a race car. (w/ catch diode of >course) The sticking contactors on production airplanes is a well known phenomenon when OEM's were using the intermittent duty versions of the RBM/White-Rogers/Stancore contactors. These looked just like the battery contactor shown at: http://www.aeroelectric.com/Pictures/Contactors/s701-1.jpg These contactors had large area, low pressure contacts like: http://www.aeroelectric.com/Pictures/Contactors/S701-1a.jpg http://www.aeroelectric.com/Pictures/Contactors/S701-1b.jpg . . . not the best way to control high inrush devices like starters. In later years, the car guys showed us small-area, high-pressure intermittent duty contactors like: http://www.aeroelectric.com/Pictures/Contactors/s702-1l.jpg http://www.aeroelectric.com/Pictures/Contactors/S702-1a.jpg Contactor sticking was virtually eliminated for systems where the battery was kept in good shape. The only cases we've seen where an owner was able to weld a small-area, high-pressure contactor was with a soggy battery that barely managed to get the contactor closed but with insufficient pressure to get good conduction, hence burned and welded contacts. We've seen starters wired with the big fat push button (or Z-22 relay) weld the built-in contacts too. If the battery is soggy or the engagement signal to the contactor is tentative, welding risks go up markedly IRRESPECTIVE of who's contactor is doing what to who's starter. I've had several builders report this phenomenon where rapping the contactor housing on the side of the starter with a screwdriver handle would cause it to become unstuck. > > >To be fair to Bob, if it ain't broke don't fix it. Nothing WRONG with the >Z diagram xyz, just suggesting if you want a lean mean electrical system >with more than adequate or even superior reliability and safety, while >lowering weight and complexity, consider trashing the BIG fw contactor. To be fair to me or anyone else, we need to be talking about the same problem. The run-on problem described was identified in a timely manner, demonstrated, explained, and fixed. It had nothing to do with sticking contactors and was unique to PM starters. The sticking contactors of an earlier design was tolerated for decades (from about 1946 through the mid 70's) because when a starter contactor did stick, it was backed up by the battery master contactor. While every airplane using the old style starter contactor suffered the phenomenon, it wasn't a big deal. When the automotive designers crafted the high-pressure design, it was welcomed by all. > The next step is get rid of the BIG master contactor. You only need a > 30-60 amp relay if you don't run the starter load through it. Anyone is completely free to get rid of any parts they wish and indeed many builders have done just that. The only thing I'll suggest is that the decisions to do so exploit the experience and thought processes behind 60+ years aircraft electrical systems. An accurate sense of history combined with an understanding of applicable simple-ideas helps us avoid potentially unhappy and unintended consequences of "the next step." If you're ready to hang your hat on an always hot, fat feeder from battery to starter mounted contactor/solenoid, keep in mind that the starter's built-in contactor can stick too. Further, you loose pilot control over making the airplane's electrical system max-cold. If those design goals are acceptable then so be it. It's your airplane and it's experimental. Fly in peace. Bob . . . ________________________________ Message 11 ____________________________________ Time: 03:02:12 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Radios OFF during startup --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" Some folks have reported problems with their email clients recognizing the address for the piece on DO-160 due to punctuation in the file title. I've revised the file name and reposted at: http://www.aeroelectric.com/articles/Whats_all_this_DO160_Stuff_Anyhow.pdf Bob . . . < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > ________________________________ Message 12 ____________________________________ Time: 03:08:33 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Why use starter contactor? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" John, Thank you for sharing this info. It tracks with what we understand about the huge list of variables that affect starter and associated contactor performance. Bottom line is that ALL starters of ANY brand are subject to undesirable behavior for a host of reasons. None of these events needs to be more than a frustrating maintenance item if we leave certain "Plan-B" options in place for dealing with them if and when they arise. Bob . . . At 04:47 PM 4/7/2006 -0500, you wrote: >--> AeroElectric-List message posted by: "John D. Heath" > > TWIMC (Which is probaly only me), > >(1) Electrial Solenoid engaged starters,as used on Lycoming, Chevrolet,BMW, >and Porsche, do stick. > >(2) Solenoid engaged starters are disengaged by a spring and an over running >mechanism in the starter gear. > >(3) I have personally seen three out of the four named, stick . > >(4) They stick and continue to crank the engine, they stick and don't crank >the engine, and all modes of stick in between. > >(5) They stick when they are new or old, clean or dirty but mostly they >stick because they are misaligned or have not been lubricated. > >(6) One of these starters that fail in the "CRANK the engine mode" with the >+12VDC wired directly to the solenoid has a great big wire as big around as >your index finger HOT and you can't turn it off. > >(7) There are many light weight relays capable of eliminating this problem >by attaching the +12VDC first to it and then on to the starter solenoid. No >device that controls the starter directly through its solenoid control >circuit can do this. > >(8) I have had multiple experiences with these type failures. Allow me to >pass these experiences on to you and eliminate the time and aggravation it >would take for you to accumulate them yourself. Use the information as you >will. ________________________________ Message 13 ____________________________________ Time: 04:02:52 PM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Re: Why use starter contactor? --> AeroElectric-List message posted by: Brian Lloyd Robert L. Nuckolls, III wrote: > Unlike wound-field motors supplied on B&C (and perhaps other) > starters, the PM offerings by Skytec (and perhaps others) are > efficient GENERATORS of electrical power while the armatures are > spinning down. When the pilot releases the starter button after > the engine fires, connection between the starter motor and battery > was being opened just fine. However, IF the starter was wired for > external contactor, voltage being generated by the coasting armature > was still applied to the solenoid engagement windings thus keeping > the pinion gear engaged for some period of time (perhaps 2-5 seconds) > after the button was released. The starter's overrun clutch prevented > damage but it was obviously an undesirable operating quality. I found this problem another way. After installation of one of these PM starters my Comanche got hard to start when warm where it hadn't been before. I didn't notice because at the time my father was flying it more than I was and had several incidents of almost running the battery down trying to start the engine when it was hot (carbureted engine, not fuel injection). This was doubly surprising as the engine was equipped with a shower of sparks ignition system. It would fire but then wouldn't 'catch' and keep running when the start button was released. The engine would spin down and seem to 'catch' just before it quit turning. It was very perplexing. (You have enough information to solve this puzzle but just for fun I will post the real problem and the fix in the next message so you can think about it for just a moment.) -- Brian Lloyd 361 Catterline Way brian-yak at lloyd dot com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . - Antoine de Saint-Exupery ________________________________ Message 14 ____________________________________ Time: 04:22:24 PM PST US From: "Steven Anderson" Subject: AeroElectric-List: Re: Checking out a radio installation --> AeroElectric-List message posted by: "Steven Anderson" I am at the stage where I want to make sure my radios and nav work before I put on the panel that makes getting at all my wiring and radio stack very difficult. In other words, I am at my garage and not near an airport. I want to order a hand held nav/com to test my Garmin SL 30. Is there a set procedure for this kind of thing. Can I just transmit on some obscure frequency and try and receive on the other? Thanks in Advance. Do not archive Steve Anderson RV 7A ________________________________ Message 15 ____________________________________ Time: 04:41:36 PM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Re: Why use starter contactor? --> AeroElectric-List message posted by: Brian Lloyd OK, where was I ... oh yeah, the hard starting Comanche after installing a PM starter. It seems that someone had wired the start lead to the shower-of-sparks system to the starter side of the start solenoid. When the start button was release the EMF generated by the still-turning PM starter would hold the shower-of-sparks relay in and that would continue to disable the right mag and keep the left mag on the retard breaker but it wouldn't provide enough voltage to get the shower-of-sparks vibrator to really do its thing. When cold the engine would freewheel better when the start button was released and the shower-of-sparks start relay would drop out before the engine lost too much RPM and it would start fine. When trying to start after just a bit of a cool down the engine was extra tight and would not freewheel so the engine spun down before the starter did. The solution? Move the start lead for the shower-of-sparks system from the starter side of the solenoid to the start button itself. Now the power went away instantly when the start button was released and the engine would catch and run just fine. BTW, this problem drove me nuts for about 6 months until I finally figured it out. -- Brian Lloyd 361 Catterline Way brian-yak at lloyd dot com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . - Antoine de Saint-Exupery ________________________________ Message 16 ____________________________________ Time: 08:01:01 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Why use starter contactor? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" Isn't it amazing how those simple-ideas stack up sometimes? Bob . . . At 04:40 PM 4/7/2006 -0700, you wrote: >--> AeroElectric-List message posted by: Brian Lloyd > >OK, where was I ... oh yeah, the hard starting Comanche after installing >a PM starter. > >It seems that someone had wired the start lead to the shower-of-sparks >system to the starter side of the start solenoid. When the start button >was release the EMF generated by the still-turning PM starter would hold >the shower-of-sparks relay in and that would continue to disable the >right mag and keep the left mag on the retard breaker but it wouldn't >provide enough voltage to get the shower-of-sparks vibrator to really do >its thing. When cold the engine would freewheel better when the start >button was released and the shower-of-sparks start relay would drop out >before the engine lost too much RPM and it would start fine. > >When trying to start after just a bit of a cool down the engine was >extra tight and would not freewheel so the engine spun down before the >starter did. > >The solution? Move the start lead for the shower-of-sparks system from >the starter side of the solenoid to the start button itself. Now the >power went away instantly when the start button was released and the >engine would catch and run just fine. > >BTW, this problem drove me nuts for about 6 months until I finally >figured it out.