---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 08/03/06: 22 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:57 AM - Re: MPJA speed control (Fiveonepw@aol.com) 2. 06:38 AM - Fw: Alternator failure quits engine (Paul Messinger) 3. 06:41 AM - Re: MPJA speed control (Sam Marlow) 4. 07:38 AM - Re: Is this solder okay? (Speedy11@aol.com) 5. 07:44 AM - Re: Is this solder okay? (Speedy11@aol.com) 6. 07:50 AM - Ground Block On Firewall () 7. 08:21 AM - Re: CB Power Source (Speedy11@aol.com) 8. 09:15 AM - Re: MPJA speed control (Mark R Steitle) 9. 10:46 AM - Re: Ground Block on Firewall (Glaeser, Dennis A) 10. 12:35 PM - Re: Re: Ground Block on Firewall (Ed Holyoke) 11. 12:49 PM - Mag switches-what size? (Steve James) 12. 01:21 PM - Re: Re: Ground Block on Firewall (Dave N6030X) 13. 01:21 PM - Re: Mag switches-what size? (FLYaDIVE@aol.com) 14. 01:28 PM - Re: Re: Ground Block on Firewall (Brian Lloyd) 15. 01:39 PM - Re: Fw: Alternator failure quits engine (Ken) 16. 02:49 PM - Re: Fw: Alternator failure quits engine (Paul Messinger) 17. 03:42 PM - Re: MPJA speed control (Fiveonepw@aol.com) 18. 05:42 PM - Re: 8.33 kHz comms (Mike) 19. 07:37 PM - Re: Ground Block On Firewall (Robert L. Nuckolls, III) 20. 07:37 PM - Re: Re: Ground Block on Firewall (Robert L. Nuckolls, III) 21. 07:40 PM - Re: Mag switches-what size? (Robert L. Nuckolls, III) 22. 07:48 PM - Re: CB Power Source (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 04:57:25 AM PST US From: Fiveonepw@aol.com Subject: Re: AeroElectric-List: MPJA speed control In a message dated 08/02/2006 3:34:49 PM Central Daylight Time, echristley@nc.rr.com writes: Has anyone else attempted to use this device to control the brightness of LEDs, and if so, how successful were you? >>> I'm using one to drive over 60 red superbrights plus the incandescents on my Van's fuel gauges. Works well with the exception of an occasional random flicker which I suspect is a AMP connector that needs some attention. I removed the variable resistor from the board and remote-located a 100Kohm, 2 watt from Digikey (# RV4N104C-ND) to the panel alongside the other lighting switches. Very linear control of all LEDs and fuel gauge bulbs, from full bright to almost completely off. Schematic on ACAD if interested... Mark Phillips ________________________________ Message 2 _____________________________________ Time: 06:38:54 AM PST US From: "Paul Messinger" Subject: Fw: AeroElectric-List: Alternator failure quits engine --> AeroElectric-List message posted by: "Paul Messinger" Reading the fine print; this is an NSI engine. Subaru, dual alternator belts, prop clutch, Europa, etc something unique to the NSI EA81. I had (last year) an identical alternator failure on my Excavator. In my case there was only a single belt and it slipped. The diesel engine only running at 2,000 rpm and the belt simply slipped, screamed smoked and the engine kept running. Hard to think the small ball bearing bearing could lock that hard but it did. The alternator bearing opposite the pulley end had frozen solid. Really solid! 2,200 hours since new. (PM "alternator" so no brushes) The NSI setup with matched dual belts has a lot of drive friction and the NSI supplied is the very common ND 55amp alternator. Something to consider as NSI alternators were rebuilt ones. Rebuilders do NOT always replace bearings if they pass the noise test or look ok. Failed at 80 hours TT, not much considering. Paul ----- Original Message ----- Sent: Wednesday, August 02, 2006 10:21 PM > --> AeroElectric-List message posted by: > > Do not arcive > > Here is a story from Europa Newsgroup figured may be of interest. > > Ron Parigoris > > Full Headers: Display Headers > Attachments: Part 1 noname (TEXT/PLAIN quoted-printable 4648 bytes) Hide > Part 2 noname (TEXT/HTML quoted-printable 5759 bytes) View > > -------------------------------------------------------------------------------- > > Our recently rebuilt Europa G-BWCV is again in pieces after we put only 30 > more > flying hrs on this engine to add to the 50hrs it had done in the hands of > the > previous owner. > > We had just received the new full permit to fly when recently, heading for > Lundy > Island just South of Bristol Docks , the cockpit filled with smoke as if a > smoke > bomb had gone off and the engine stopped! I could not discern whether the > smoke > was electrical in origin but assumed as the engine had stopped it had to > be. > > The cause and subsequent sequence of events has now been established. > > Alternator bearing seizure initiated dual rubber v-belt slip at the > crankshaft > pulley. > In 2-3 seconds 50 cruise hp turned both rubber belts into smoke and > vulcanised > them instead of driving the now freewheeling prop (no flywheel effect to > snap > belts). > > The alternator was switched off immediately but to no benefit since its > load was > not the issue. > > So instead of the crankshaft pulley driving the alternator, the alternator > now > seized was now driving the engine to a stop! A relatively minor accessory > failure > had initiated a cascade of events equivalent or even worse than a major > engine > failure. > > Ofcourse this should not happen should it? > > Little did I know I had become an involuntary test pilot!!!!!!!with an > observer!!!!! > > The idea of a re-start attempt was not surprisingly quickly rejected. > However, as > I now know it would obviously have been a futile exercise, the engine > stopped > from 50hp running so the starter did not have a chance. > > Two other aspects of this incident made for an extremely high workload. > > 1. I had to switch off all electrics to prevent any further risk of smoke > (if > only to be able to see out for a forced landing) or worse still fire. This > meant > I lost the electric trim. > > This may appear a small thing but believe me, this meant the constant use > of one > hand flying the stick without feel and as a consequence one eye glued to > the ASI. > A workload I did not need at this time. Mechanical trim would have helped > enormously. > > Try your practice forced landings in cruise trim to see what I mean. "It > could be > you." > > 2. The other aspect which is a little more difficult to practice was the > free > wheeling prop. All practice forced landings to date had been with the > engine at > idle as is usual. In this condition increasing speed, by diving, increases > engine > rpm so the sprag clutch is effectively connecting engine and propeller > like any > other engine. > When the engine stopped, I was quickly aware of an abnormally high rate of > descent. The prop ran away like a wind generator in hurricane, the feel of > the > stick was abnormal due to the out of trim load and I think also the > braking > effect on the airflow over the tail.of the prop now in drag parachute > mode. > > The location was far from ideal for a forced landing and with the high > rate of > descent meaning short time for descent we could easily have come off far > worse > especially since the area was well populated with power lines of different > sizes > forcing a late rejection of the primary field selection. > > Having taken the diagonal in anticipation of the limited field size We hit > the > far hedge in a 290 meter 30+ Celcius almost max gross with wind light and > variable as the sea breeze was backing up the Severn valley. The near > hedge > incidentally was a 6 foot steep bank from a wide drainage canal. This, > coupled > with the unusual deck angle in the glide which only got worse of course > when I > put the coupled gear and flap down on the Mono, requiring an unusually > long > duration flare as if landing up hill, put our aiming point considerably > before > the actual touch down point so we were going to hit the hedge. The last > trick I > had up my sleeve from my cross country gliding days was to drop the gear > in order > to minimise the ground roll. This in retrospect, although it did no such > thing, > probably stopped us flipping upside down. I never considered applying the > brake > but the wheel just keeps turning judging by our grass marks.Which > fortunately I > was able to pace out having vacated the aircraft. > > I am giving a talk to Gloucester strut about the Europa rebuild and now > have a > new chapter. > > It is in the Aeros flying club building next Tuesday at 07.30 pm and would > welcome anyone especially Subaru owners to come along. > > I still like the Subaru engine and would be happy to fly it again once > this > single point failure has been addressed. If the Europa flies again it will > be > called hedgehog! > > > ________________________________ Message 3 _____________________________________ Time: 06:41:09 AM PST US From: Sam Marlow Subject: Re: AeroElectric-List: MPJA speed control Where do I purchase one of these, and what is ACAD? Fiveonepw@aol.com wrote: > In a message dated 08/02/2006 3:34:49 PM Central Daylight Time, > echristley@nc.rr.com writes: > > Has anyone else attempted to use this device to control the > brightness > of LEDs, and if so, how successful were you? > > >>> > > I'm using one to drive over 60 red superbrights plus the incandescents > on my Van's fuel gauges. Works well with the exception of an > occasional random flicker which I suspect is a AMP connector that > needs some attention. I removed the variable resistor from the board > and remote-located a 100Kohm, 2 watt from Digikey (# RV4N104C-ND) to > the panel alongside the other lighting switches. Very linear control > of all LEDs and fuel gauge bulbs, from full bright to almost > completely off. Schematic on ACAD if interested... > > Mark Phillips ________________________________ Message 4 _____________________________________ Time: 07:38:36 AM PST US From: Speedy11@aol.com Subject: AeroElectric-List: Re: Is this solder okay? Brian, Thank you for your prompt and informative reply. Stan Sutterfield Do not archive Normally the tin content is listed first and the stuff you want is very close to 60% tin and 40% lead. This is known as 60/40 solder. If what you are looking at is 40/60 you definitely don't want it. ________________________________ Message 5 _____________________________________ Time: 07:44:49 AM PST US From: Speedy11@aol.com Subject: AeroElectric-List: Re: Is this solder okay? Barry, Excellent info for an ignorant pilot. Thank you. I checked the package and it does say 40/60 tin-lead, so I won't use it. I'll locate the Eutectic solder. Stan Sutterfield Do not archive 40/60 NO! But, I think you have the numbers mixed up, it is probably 60/40. If it is 60/40 that is acceptable but not the best. See if you can find 63/37 it is know as Eutectic Solder. ________________________________ Message 6 _____________________________________ Time: 07:50:05 AM PST US From: Subject: AeroElectric-List: Ground Block On Firewall --> AeroElectric-List message posted by: I wish to install one of the multi tab type ground blocks to the stainless steel firewall on my RV8-A. This will have a block of tabs on both sides of the firewall. Do I need to anything special to the stainless steel to prepare the surface? Since I will be grounding many items in the aircraft to these gounds, I want to insure that this is a really good ground. Also is it necessary to have the mounting bolt go into one of the aluminum angles behind the firewall or is it enought just to have the bolt go through the stainless? Any help or comments are most welcome. Jeff ________________________________ Message 7 _____________________________________ Time: 08:21:13 AM PST US From: Speedy11@aol.com Subject: AeroElectric-List: Re: CB Power Source My appreciation to Bob and Chop'd Liver for their advice regarding powering circuit breakers. Stan Sutterfield Do not archive ________________________________ Message 8 _____________________________________ Time: 09:15:54 AM PST US From: "Mark R Steitle" Subject: RE: AeroElectric-List: MPJA speed control Hi Ernest, Yes, I'm using the MPJA pwm speed controller for dimming LED's. In the attached jpg. you can see the string of led's across the top of my panel which are controlled by a single MPJA speed controller. I too repositioned the potentiometer with a remote unit of higher quality. All of my circuits were configured from the manufacturer to operate on 12v as the MPJA pwm speed controller is designed to operate a 12v motor. Works great with no noticeable flicker. Mark S. -----Original Message----- [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Ernest Christley Sent: Wednesday, August 02, 2006 3:28 PM --> AeroElectric-List message posted by: Ernest Christley I read of the MPJA DC motor speed controller kit being used as a light dimmer, so I ordered me one. Had it together in an afternoon and breadboarded up some LEDs to give it a test. I have access to a scope to check what it's doing, but haven't had time to go by Mark's shop yet. So far, I find the light flickers visibly, and there is only a very small change in the brightness as the adjustment knob is turned. Has anyone else attempted to use this device to control the brightness of LEDs, and if so, how successful were you? -- ,|"|"|, Ernest Christley | ----===<{{(oQo)}}>===---- Dyke Delta Builder | o| d |o http://ernest.isa-geek.org | ========================= ========== ========================= ========== ========================= ========== ========================= ========== ________________________________ Message 9 _____________________________________ Time: 10:46:33 AM PST US From: "Glaeser, Dennis A" Subject: AeroElectric-List: Re: Ground Block on Firewall --> AeroElectric-List message posted by: "Glaeser, Dennis A" The firewall is just a place to hang the ground block. It doesn't participate electrically in any significant matter - that's why everything is connected to the ground block. Since you will have ground blocks on both sides of the firewall, you need to be sure they are connected well electrically - like with a nice brass bolt (available from the Aviation/Plumbing aisle at Lowes or Home Depot). B&C has a grounding block kit you can either get, or emulate. I don't think it is necessary to mount it to one of the angles, but if it is convenient, it wouldn't hurt. I haven't mounted mine yet, but if it feels flimsy just mounted to the firewall, I'll put in a backing plate (probably .040 aluminum). Dennis Glaeser RV7A - Finishing Kit ------------------------------------------------------------------------ ------------------- Subject: Ground Block On Firewall From: jmoreau2@cox.net I wish to install one of the multi tab type ground blocks to the stainless steel firewall on my RV8-A. This will have a block of tabs on both sides of the firewall. Do I need to anything special to the stainless steel to prepare the surface? Since I will be grounding many items in the aircraft to these gounds, I want to insure that this is a really good ground. Also is it necessary to have the mounting bolt go into one of the aluminum angles behind the firewall or is it enought just to have the bolt go through the stainless? Any help or comments are most welcome. Jeff ________________________________ Message 10 ____________________________________ Time: 12:35:06 PM PST US From: "Ed Holyoke" Subject: RE: AeroElectric-List: Re: Ground Block on Firewall --> AeroElectric-List message posted by: "Ed Holyoke" But what about stuff that's grounded locally on the wing such as pitot heat, landing lights, etc.? That stuff's ground has to make it's way to the forest of tabs on the firewall and back to the battery through the stainless firewall. If the firewall is as poor a conductor as has been recently said, doesn't that raise the possibility of ground loops as the pitot heat, lights, etc. try to return and wind up finding an easier route such as through the chassis of a radio? Pax, Ed Holyoke --> AeroElectric-List message posted by: "Glaeser, Dennis A" The firewall is just a place to hang the ground block. It doesn't participate electrically in any significant matter - that's why everything is connected to the ground block. Since you will have ground blocks on both sides of the firewall, you need to be sure they are connected well electrically - like with a nice brass bolt (available from the Aviation/Plumbing aisle at Lowes or Home Depot). B&C has a grounding block kit you can either get, or emulate. I don't think it is necessary to mount it to one of the angles, but if it is convenient, it wouldn't hurt. I haven't mounted mine yet, but if it feels flimsy just mounted to the firewall, I'll put in a backing plate (probably .040 aluminum). Dennis Glaeser RV7A - Finishing Kit ------------------------------------------------------------------------ ------------------- Subject: Ground Block On Firewall From: jmoreau2@cox.net I wish to install one of the multi tab type ground blocks to the stainless steel firewall on my RV8-A. This will have a block of tabs on both sides of the firewall. Do I need to anything special to the stainless steel to prepare the surface? Since I will be grounding many items in the aircraft to these gounds, I want to insure that this is a really good ground. Also is it necessary to have the mounting bolt go into one of the aluminum angles behind the firewall or is it enought just to have the bolt go through the stainless? Any help or comments are most welcome. Jeff ________________________________ Message 11 ____________________________________ Time: 12:49:34 PM PST US From: "Steve James" Subject: AeroElectric-List: Mag switches-what size? I want to use smaller size switches in place of the normal rotary type mag switch. What is minimum current rating/volt rating for such a switch when used with regular mags? Since these ground the mags, it's not clear to me how to size them... any input is appreciated. Thx, Steve. ________________________________ Message 12 ____________________________________ Time: 01:21:22 PM PST US From: Dave N6030X Subject: RE: AeroElectric-List: Re: Ground Block on Firewall --> AeroElectric-List message posted by: Dave N6030X Don't just leave the FOT on each side of the firewall trying to find their grounds through the firewall metal somehow. Hook up a big fat ground wire directly from the bolt to the battery. The bolt a ground wire from the wing to the battery (or FOT) as well. Dave Morris At 02:29 PM 8/3/2006, you wrote: >--> AeroElectric-List message posted by: "Ed Holyoke" > >But what about stuff that's grounded locally on the wing such as pitot >heat, landing lights, etc.? That stuff's ground has to make it's way to >the forest of tabs on the firewall and back to the battery through the >stainless firewall. If the firewall is as poor a conductor as has been >recently said, doesn't that raise the possibility of ground loops as the >pitot heat, lights, etc. try to return and wind up finding an easier >route such as through the chassis of a radio? > >Pax, > >Ed Holyoke > > >--> AeroElectric-List message posted by: "Glaeser, Dennis A" > > >The firewall is just a place to hang the ground block. It doesn't >participate electrically in any significant matter - that's why >everything is connected to the ground block. Since you will have ground >blocks on both sides of the firewall, you need to be sure they are >connected well electrically - like with a nice brass bolt (available >from the Aviation/Plumbing aisle at Lowes or Home Depot). B&C has a >grounding block kit you can either get, or emulate. > >I don't think it is necessary to mount it to one of the angles, but if >it is convenient, it wouldn't hurt. I haven't mounted mine yet, but if >it feels flimsy just mounted to the firewall, I'll put in a backing >plate (probably .040 aluminum). > >Dennis Glaeser >RV7A - Finishing Kit > >------------------------------------------------------------------------ >------------------- > >Subject: Ground Block On Firewall >From: jmoreau2@cox.net > >I wish to install one of the multi tab type ground blocks to the >stainless steel >firewall on my RV8-A. This will have a block of tabs on both sides of >the firewall. >Do I need to anything special to the stainless steel to prepare the >surface? >Since I will be grounding many items in the aircraft to these gounds, I >want to >insure that this is a really good ground. >Also is it necessary to have the mounting bolt go into one of the >aluminum angles >behind the firewall or is it enought just to have the bolt go through >the stainless? >Any help or comments are most welcome. >Jeff > > ________________________________ Message 13 ____________________________________ Time: 01:21:31 PM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: Mag switches-what size? In a message dated 8/3/2006 3:53:58 PM Eastern Standard Time, stevesrv7@gmail.com writes: I want to use smaller size switches in place of the normal rotary type mag switch. What is minimum current rating/volt rating for such a switch when used with regular mags? Since these ground the mags, it's not clear to me how to size them... any input is appreciated. Thx, Steve. ============================= Steve: I guess you are considering TWO Single Pole Single Throw (SPST) switches. Well, all that the switch is doing is supplying a Path to Ground for the 'P' Lead. What is important is NOT the voltage or current rating but the Mechanical Construction and Reliability. What I used was two (2) standard SPST 15 Amp switches. Nice solid switches that can handle the abuse you will be giving them. They will not fail because of voltage or current, but they can fail because of abuse. I would NOT use mini or micro sized switches. Get a switch that has a nice strong SNAP when opened or closed. Barry "Chop'd Liver" "Show them the first time, correct them the second time, kick them the third time." Yamashiada ________________________________ Message 14 ____________________________________ Time: 01:28:34 PM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Re: Ground Block on Firewall --> AeroElectric-List message posted by: Brian Lloyd On Aug 3, 2006, at 3:29 PM, Ed Holyoke wrote: > --> AeroElectric-List message posted by: "Ed Holyoke" > > > But what about stuff that's grounded locally on the wing such as pitot > heat, landing lights, etc.? That stuff's ground has to make it's > way to > the forest of tabs on the firewall and back to the battery through the > stainless firewall. If the firewall is as poor a conductor as has been > recently said, doesn't that raise the possibility of ground loops > as the > pitot heat, lights, etc. try to return and wind up finding an easier > route such as through the chassis of a radio? The firewall is not a poor conductor. A big slab of stainless steel, while less conductive than an equivalent copper plate, is still a very good conductor. As for ground loops, we really don't have ground loops, just multiple paths. The current from your pitot heat and landing light is going to return to the battery negative through the airframe to the firewall. This is not going to be a problem. The real advantage of the single-point ground is to reduce the number of multiple path returns, especially for more sensitive equipment like avionics. What you propose, grounding your pitot heat, positions lights, and landing light(s) to the airframe will work just fine and will not cause any problems. 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-Exupry ________________________________ Message 15 ____________________________________ Time: 01:39:25 PM PST US From: Ken Subject: Re: Fw: AeroElectric-List: Alternator failure quits engine --> AeroElectric-List message posted by: Ken Thank for sharing this story. Seems we were recently discussing bearing failures. I've never believed in dual belts for most applications unless the load was clearly way too high for one belt. It tends to increase bearing loads (especially if they are not well matched) and if one belt fails it may take out the other anyway. I've never had a belt fail although I do replace them about every 4 years or 60k miles (100k km.) on my cars and check the tension occasionally. I did use separate belts for each of my alternators, make sure that the pulleys were aligned, and use solid alternator mounts, but I don't consider a single belt to be a reliability concern. I have even accepted a very small risk that a failed belt (for whatever reason) could foul my EJ22 camshaft belt. Ken ________________________________ Message 16 ____________________________________ Time: 02:49:09 PM PST US From: "Paul Messinger" Subject: Re: Fw: AeroElectric-List: Alternator failure quits engine --> AeroElectric-List message posted by: "Paul Messinger" The original application of the NSI dual belts was to lower the side load on the water pump as well as belt slippage. The result was the ability to use much lower belt tension which is a good thing. Doubles the friction and permits lower tension with no slippage. The NSI supplied belts are matched. Replacement belts may not be matched. I agree mismatched belts can be a problem as well as excessive tension. To me the issue is the widespread use of rebuilt alternators which often have well used and or the lowest cost bearings available as rebuilders are cost driven. Both Vans and NSI have used rebuilt alternators. And as I have found out rebuilt alternators is a false term in my opinion as they are only repaired to "used auto standards" not rebuilt to "like new" standards. There is a huge range of bearing quality for example. If the bearing is not excessively noisy its not replaced. The flag I see is not dual belts but the quality of rebuilt alternators which in my opinion have no place in an aircraft. Buy a new internal reg ND or buy a new external B and C. This incident should be reason enough. Paul ----- Original Message ----- Sent: Thursday, August 03, 2006 1:40 PM > --> AeroElectric-List message posted by: Ken > > Thank for sharing this story. Seems we were recently discussing bearing > failures. > I've never believed in dual belts for most applications unless the load > was clearly way too high for one belt. It tends to increase bearing loads > (especially if they are not well matched) and if one belt fails it may > take out the other anyway. I've never had a belt fail although I do > replace them about every 4 years or 60k miles (100k km.) on my cars and > check the tension occasionally. I did use separate belts for each of my > alternators, make sure that the pulleys were aligned, and use solid > alternator mounts, but I don't consider a single belt to be a reliability > concern. I have even accepted a very small risk that a failed belt (for > whatever reason) could foul my EJ22 camshaft belt. > Ken > > > http://www.matronics.com/Navigator?AeroElectric-List > http://wiki.matronics.com > > > ________________________________ Message 17 ____________________________________ Time: 03:42:45 PM PST US From: Fiveonepw@aol.com Subject: Re: AeroElectric-List: MPJA speed control Get 'em here: http://mpja.com/productview.asp?product=4057+MD Very simple kit that is a great brush-up or introduction on electronic assembly. Here is my installation: http://websites.expercraft.com/n51pw/index.php?q=log_entry&log_id=5003 Dimmer is lower left corner of tray- fwd/rev switch is removed and small brace is installed to help support heat sink. ACAD is short for AutoCAD. Being a semi-geekly electrical kind of guy, I did all my electrical diagrams (Z-11 variant) using ACAD. Handy stuff for those so inclined... Mark Phillips http://websites.expercraft.com/n51pw/ ________________________________ Message 18 ____________________________________ Time: 05:42:29 PM PST US From: "Mike" Subject: RE: AeroElectric-List: 8.33 kHz comms But a digital radio is more likely here but I would bet in either case you would almost wear out your radio by the time it takes effect Mike L.. -----Original Message----- [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of sportav8r@aol.com Sent: Wednesday, August 02, 2006 9:29 AM I've been planning on a garmin SL-30 nav/comm for a future panel upgrade, but Garmin tech support today just confirmed a fear of mine: they have no plans to make either the SL-30 or SL-40 compatible with the new tighter spacing. I suppose one option is to plan on upgrading comm2 to 8.33kHz when needed and leaving the SL-30 as-is. Anyone know when the new channelization is going to become mandatory in the US? I hear it's coming, someday. What are some good options for current production nav-comms that offer this feature already? I don't need a gps/nav/comm unit since I plan to run GRT's gps as a stand-alone IFR unit, so the 430, 530, 480 are all too much radio for my needs. Thanks. -Bill B. _____ -- -- ________________________________ Message 19 ____________________________________ Time: 07:37:34 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Ground Block On Firewall --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:47 AM 8/3/2006 -0400, you wrote: >--> AeroElectric-List message posted by: > >I wish to install one of the multi tab type ground blocks to the stainless >steel firewall on my RV8-A. This will have a block of tabs on both sides >of the firewall. >Do I need to anything special to the stainless steel to prepare the surface? >Since I will be grounding many items in the aircraft to these gounds, I >want to insure that this is a really good ground. >Also is it necessary to have the mounting bolt go into one of the aluminum >angles behind the firewall or is it enought just to have the bolt go >through the stainless? >Any help or comments are most welcome. The whole purpose of the ground block is to take the firewall sheet out of the equation irrespective of what ever material it is made of. When you use the single point ground block that is THE ground. The airplane (if it happens to be metal) becomes grounded to it, not the other way around. If the airplane happens to be plastic, then obviously, the airplane doesn't get 'grounded'. So your concerns about the ground-block to airplane interface are not well founded. If your airframe local grounds are limited to the items oft suggested (wing mounted lights, pitot heaters, strobe supplies) then simply bolting a clean ground block to stainless firewall with hardware supplied is quite sufficient. I'd torque the fasteners to max rated for the materials and call it good. Even if you remote mount the battery with local grounding (See: http://aeroelectric.com/articles/Battery_Grounds/Battery_Grounds.html ) the technique described above is quite sufficient. The key words are "clean" and "pressure." The "fat" bolt and nuts are 5/16" brass (typically 1/2 yield strength of steel so 50 in-lb torque) . The smaller holes in the ground blocks should be bolted to the firewall with 10-32 steel screws and metal lock nuts (25 in-lb + "drag torque"). See section 7 of AC43-13. If the parts go together clean, then sustained pressure will keep the contact areas clean for the lifetime of the airplane. Bob . . . ________________________________ Message 20 ____________________________________ Time: 07:37:34 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Re: Ground Block on Firewall --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:29 PM 8/3/2006 -0700, you wrote: >--> AeroElectric-List message posted by: "Ed Holyoke" > >But what about stuff that's grounded locally on the wing such as pitot >heat, landing lights, etc.? That stuff's ground has to make it's way to >the forest of tabs on the firewall and back to the battery through the >stainless firewall. If the firewall is as poor a conductor as has been >recently said, it's not necessarily a "poor" conductor, just harder to achieve and sustain good electrical connection . . . clean and pressure. > doesn't that raise the possibility of ground loops as the >pitot heat, lights, etc. try to return and wind up finding an easier >route such as through the chassis of a radio? not if you get clean and apply pressure . . . and since all radios and other potential victims for noise are NOT grounded to the airframe but to grounding features described in Figure Z15, then ground loop possibilities are eliminated no mater what else is going on in the system. Bob . . . ________________________________ Message 21 ____________________________________ Time: 07:40:58 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Mag switches-what size? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 01:45 PM 8/3/2006 -0600, you wrote: >I want to use smaller size switches in place of the normal rotary type mag >switch. What is minimum current rating/volt rating for such a switch when >used with regular mags? Since these ground the mags, it's not clear to me >how to size them... any input is appreciated. Thx, Steve. Plain vanilla toggle switches are fine. See http://www.aeroelectric.com/Pictures/Switches/s700dwg.jpg http://www.aeroelectric.com/Pictures/Switches/switch2.jpg Magnetos are not especially "stressful" to their controlling switches. The standard toggle has been the ignition switch of choice called out in the z-figures since day-one irrespective of the ignition system technology. 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 22 ____________________________________ Time: 07:48:59 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: CB Power Source --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:46 PM 8/2/2006 -0400, you wrote: >--> AeroElectric-List message posted by: FLYaDIVE@aol.com > >In a message dated 8/2/06 8:09:51 PM Eastern Daylight Time, Speedy11@aol.com >writes: > > > I am using circuit breakers in my electrical system. > > I had planned to use copper bars to provide power to the "line" side of >the > > CBs. > > However, it seems that would make maintenance more difficult if I needed >to > > remove only one CB. > > SO, what do you think about using jumper wires from CB to CB to provide > > power > > to the CBs? Maybe use #12 AWG to carry the load. > > Has anyone done that? Any issues? > > Stan Sutterfield >============================ >Stan: > >There is nothing wrong with that, the procedure works very well. >A little trick is to use one continuous length of wire, no cuts, no splices. >Leave enough bare wire between each CB to form a nice loop and so that you >can fold it back on itself and insert it into a ring lug. Low resistance, >solid >mechanical connection, looks good and as you said, easy to maintain. Generally the cross section of a "bus" conductor is sized for the alternator capacity of the airplane. If you use wire as suggested, then the terminals to accept the doubled-over wires get pretty hoggy. The terminals and service loops hang way outside the mounting footprint of the breakers. 99.9% plus of all breakers installed on all airplanes go the lifetime of the airplane never being called upon to "trip" nor do they require a maintenance action. Solid bus bars as described earlier have been used on tens of thousands of aircraft. I guarantee you that ten years from now "breaker replacement" will be WAaaaayyyy down on the list of service expenses for your airplane. 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 > ---------------------------------------------------------