---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 03/25/08: 24 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:58 AM - Re: [!! SPAM] Re: Rotax 582 Starter Problem? (Guy Buchanan) 2. 02:56 AM - oddball 0.25" fast-on terminal source? (D Wysong) 3. 04:17 AM - Re: B&C SD-20 and magnetic interference (Robert L. Nuckolls, III) 4. 04:23 AM - Re: DME/Transponder Suppression (Robert L. Nuckolls, III) 5. 04:48 AM - Re: [!! SPAM] Re: Rotax 582 Starter Problem? (Robert L. Nuckolls, III) 6. 04:54 AM - Re: oddball 0.25" fast-on terminal source? (Robert L. Nuckolls, III) 7. 07:38 AM - Re: oddball 0.25" fast-on terminal source? (Rodney Dunham) 8. 07:42 AM - Re: oddball 0.25" fast-on terminal source? (Ken) 9. 11:08 AM - WX-500 Install Manual (Don Curry) 10. 01:13 PM - Question about Resistors (Scott R. Shook) 11. 01:45 PM - Re: B&C SD-20 and magnetic interference (Carl Morgan) 12. 02:31 PM - Alternator (Bryan) 13. 03:51 PM - Re: Question about Resistors (Vernon Little) 14. 04:07 PM - Re: B&C SD-20 and magnetic interference (Matt Prather) 15. 04:13 PM - KX-155 Audio Out (txpilot) 16. 04:41 PM - Re: Question about Resistors (RALPH HOOVER) 17. 04:51 PM - Re: oddball 0.25" fast-on terminal source? (RALPH HOOVER) 18. 04:54 PM - Re: KX-155 Audio Out (n801bh@netzero.com) 19. 04:54 PM - Re: B&C SD-20 and magnetic interference (Carl Morgan) 20. 05:08 PM - Re: Question about Resistors (Scott R. Shook) 21. 06:21 PM - Re: B&C SD-20 and magnetic interference (Kevin Horton) 22. 07:06 PM - Re: B&C SD-20 and magnetic interference (Carl Morgan) 23. 08:20 PM - Re: Alternator (Mike Creek) 24. 09:02 PM - Re: oddball 0.25" fast-on terminal source? (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 12:58:43 AM PST US From: Guy Buchanan Subject: Re: [!! SPAM] Re: AeroElectric-List: Rotax 582 Starter Problem? At 03:00 PM 3/24/2008, you wrote: >In all likelihood, your battery is simply gone south > with loose connections or bad switching running in > second place. The foregoing suggests that with some > measurements, it's pretty easy to tell what needs to > be done before you get out the wrenches or go into > the swaptronics mode of troubleshooting. Bob, You were right, the battery had suddenly and inexplicably gone south. When jumped with an enormous RV battery the 582 still had a difficult time starting, but it started. The dead battery wouldn't accept a charge, (measured by the load meter,) so I guess it was well and truly dead. I tried jumping from various locations, eliminating various wires, and the engine started slowly every time. I was unable to eliminate one wire, though because of access, so that will have to wait until I can pull the engine. I'll then be able to check the starter too. I'll check cranking voltage against your recommended numbers first, though. As an aside, how do the "low amp" testers work? (E.g. DHC BT002 Battery Tester, Auto Meter BVA-350 Battery Tester) Thanks, Guy Buchanan San Diego, CA K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar. ________________________________ Message 2 _____________________________________ Time: 02:56:33 AM PST US From: "D Wysong" Subject: AeroElectric-List: oddball 0.25" fast-on terminal source? Hello all, I'm fabricating a new harness for my voltage regulator (Zeftronics regulator for a Cessna) and am searching for a supplier of uninsulated 0.25" female fast-on terminals that have a small tab sticking out of the 'back' that will lock them inside the plastic backshell. I've checked the Mouser, Newark, B&C, Waytek, and Allied catalogs without luck. However, perhaps I'm not using the correct keyword to find these oddball terminals in their search engines. Perhaps an autoparts store would carry them (the original Cessna regulator was a Ford part, I believe)? Thanks for any suggestions you folks can provide. D ________________________________ Message 3 _____________________________________ Time: 04:17:43 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: B&C SD-20 and magnetic interference At 09:44 AM 3/25/2008 +1300, you wrote: > > >Hi, > >We have been running for about 20 hours now chasing different problems. One >outstanding one is magnetic interference from the SD-20 / LR3 combination. >We have a TSO'd vertical card compass (and yes it is a southern hemisphere >model) mounted in the middle of the panel area (center/center). We are dual >alt / dual bus configuration. > >When the field wire is connected to the SD-20 (lower connection) we get up >to 40 degree swing on the compass - it does vary in amount (from 20-40 >degrees) based on direction - south seems the worst. Pulling the field >breaker causes it swings back about 30 degrees, but the regulator / alt are >still have an affect. > >B&C are saying some swing is 'normal' - but 40 degrees - I'm struggling! I >can't calibrate that much out (best effort so far is +- 15 degrees). > >I've tried changing the location / orientation of the regulator - no >difference. I've tried moving another wet compass around the panel / >cockpit - it looks like same problem (although a bit hard to tell). > >I've tried running some grounded braid around the firewall forward side of >the field wire - no change. Same symptoms on ground, air, zero RPM and full >power. There may be a small movement (< 3 degrees) based on current draw >from SD-20. With SD-20 field disconnected and X-Feed in - no movement. > >Questions: > a) Have others got this / solved this? > b) Any suggested methods of screening the SD-20? > >Thanks, > >Carl The problem is magnetic, not electrical. Had this problem on the Bonanza too. The SD-20 (as do most alternators) has a considerable leakage of magnetic flux from the rotor winding. This isn't a problem for most installations where the alternator mounts on the front of the engine. Alternators hung on the rear of the engine are much closer to the instrument panel and more likely to be an issue with a panel mounted compass. In the Bonanza, we moved the compass off the glareshield to a location on higher on the windshield. Adding a magnetic shield around the SD-20 is a pretty busy task. The shield material would have to be magnetic and cover the rear and perhaps the circumference of the alternator. This has some issues with cooling, wiring egress and labor to implement it. The easiest fix is to increase distance between the compass and the alternator. Magnetic 'radiation' is a weak propagator . . . a little distance really helps. Alternatively, an electronic compass with a remote sensor out in a wing is the best way to achieve the highest performance in a magnetic direction indicator. The case can be made that since you have 3 sources of DC power, reliability of the electronic compass is assured. I would also hope that you carry a hand-held GPS in the flight bag too. I'm not sure I'd bother to install a whisky compass any more. Likelihood of ever needing one these days is about nil. Same thing happened to buggy whips. We were fortunate not to be plagued by the FHA (Federal Horsecart Administration) when the transition occurred. Hmmmm . . . maybe they didn't really go away . . . they just morphed into radio antennas. Let's be really clear about this condition. This is NOT a downside checkmark on the blackboard for the B&C SD-20. ALL alternators have a steel shaft that runs through the device parallel to the magnetic lines of force generated in the field windings. See: http://www.aeroelectric.com/Pictures/Alternators/Alternator_w_Internal_Fan2.gif This mechanical feature insures that EVERY alternator will present a strong external magnetic field. It's a system integration problem that seldom presents but has multiple solutions for maintaining flight-system reliability. The REAL problem is getting those-who-know-more- about-airplanes-than-we-do to join us in the 21st century. Bob . . . ________________________________ Message 4 _____________________________________ Time: 04:23:58 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: DME/Transponder Suppression At 11:14 PM 3/24/2008 -0400, you wrote: > >When a KT-76A transponder and a KN-63 DME are installed in an aircraft, and >the two units are connected via suppression circuitry built into both units, >is it necessary to comply with the requirement for there to be 6-foot >spacing between the two antennae? I can't find an exception to this rule in >the install manual for either unit, yet I understand the suppression circuit >is designed to keep each unit from receiving the other unit's transmission. >So, why should it matter how close the antennae are to eachother? Transponders and DME use frequencies very close to each other and there's risk of receiver overloading in one device due to the very strong signal from the other device. This is mostly mitigated electronically via the suppression system but the 6' rule gave the engineers and marketing types a warmer set of fuzzies. Give it a try doing the best you can. It will probably be fine. Have you considered a GPS receiver in lieu of DME? DME works with a hand full of ground stations while GPS will give you distance to any point on the surface of the earth. DME is one of those electronic buggy whips that needs to be moved to the museum. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 5 _____________________________________ Time: 04:48:06 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: [!! SPAM] Re: AeroElectric-List: Rotax 582 Starter Problem? At 10:58 PM 3/24/2008 -0700, you wrote: >At 03:00 PM 3/24/2008, you wrote: >>In all likelihood, your battery is simply gone south >> with loose connections or bad switching running in >> second place. The foregoing suggests that with some >> measurements, it's pretty easy to tell what needs to >> be done before you get out the wrenches or go into >> the swaptronics mode of troubleshooting. > >Bob, > You were right, the battery had suddenly and inexplicably gone > south. When jumped with an enormous RV battery the 582 still had a > difficult time starting, but it started. The dead battery wouldn't accept > a charge, (measured by the load meter,) so I guess it was well and truly > dead. I tried jumping from various locations, eliminating various wires, > and the engine started slowly every time. I was unable to eliminate one > wire, though because of access, so that will have to wait until I can > pull the engine. I'll then be able to check the starter too. I'll check > cranking voltage against your recommended numbers first, though. > As an aside, how do the "low amp" testers work? (E.g. > >DHC BT002 Battery Tester, Auto Meter BVA-350 Battery Tester) > I've seen these kinds of things in the repair shops. These are obviously NOT load testers in the usual sense. There's no way these little fellers can accept that much energy and dump the heat through those little leads and small hand-held cases. My guess is that they're internal impedance testers of some variety. Hit the battery with 100A for a few milliseconds, get a quick reading, compute internal resistance by dividing delta-E by delta-I. Obviously, they have many other features too. It would be interesting to get my hands on one and watch it do the full bag of tricks. I did a design for a client some years ago for a cranking system tester. It was nothing more than a processor driven data acquisition system that took 6 readings of voltage around the system referenced to battery(-) terminal. It filtered the short term perturbations and offered a digital display of minimums and averages for the 6 measurement points. With one setup and one short cranking interval, it would map the system's voltage drops. I don't know if that ever went to production. Haven't heard from them in years. It was the first time I was able to take advantage of the agility offered by microelectronics to make measurements that even the most skilled observer with a multimeter would not be able to duplicate. That design had a lot of components that are now contained in a single micro-controller. It would be VERY easy to do the same product today with a bill of materials of less than $30! It could even offer 8 to 12 channels of monitoring capability. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 6 _____________________________________ Time: 04:54:20 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: oddball 0.25" fast-on terminal source? At 03:50 AM 3/25/2008 -0600, you wrote: > >Hello all, > >I'm fabricating a new harness for my voltage regulator (Zeftronics >regulator for a Cessna) and am searching for a supplier of uninsulated >0.25" female fast-on terminals that have a small tab sticking out of >the 'back' that will lock them inside the plastic backshell. I've >checked the Mouser, Newark, B&C, Waytek, and Allied catalogs without >luck. However, perhaps I'm not using the correct keyword to find >these oddball terminals in their search engines. Perhaps an autoparts >store would carry them (the original Cessna regulator was a Ford part, >I believe)? > >Thanks for any suggestions you folks can provide. I've never found these as loose fabrication or repair parts . . . but that doesn't mean somebody doesn't have them. Most builders use individual fast-on terminals and ditch the housing. You can buy the housing with terminals installed and short pig-tails at some care parts stores. I think I've seen them in the red "Help" line of blister-packed, peg-board products. I can get you a part number for a reel of 5,000! B&C used to have some that were used with the housing that fits the connector on the back of an alternator. These were bare-brass (un-plated) parts. They might work with your regulator tabs connector housing. I'd go with the loose PIDG fast-on terminals and ditch the housing. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 7 _____________________________________ Time: 07:38:27 AM PST US From: Rodney Dunham Subject: RE: AeroElectric-List: oddball 0.25" fast-on terminal source? "uninsulated 0.25" female fast-on terminals that have a small tab sticking out of the 'back' that will lock them inside the plastic backshell" I have bought just such a part for the voltage regulator connector on my pl ane from NAPA aircraft and auto parts store. Rodney in Tennessee _________________________________________________________________ In a rush? Get real-time answers with Windows Live Messenger. http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_Refr esh_realtime_042008 ________________________________ Message 8 _____________________________________ Time: 07:42:35 AM PST US From: Ken Subject: Re: AeroElectric-List: oddball 0.25" fast-on terminal source? If you really want them I believe I have purchased these, tin plated, in small quantity, cut from a reel, from digi-key however they are open barrel crimps (cheap automotive) onto the wire. There were at least two sizes listed depending on wire gauge. You want the small for tefzel or just clip the fingers. Like Bob, I prefer to shove individual PIDG connectors into the housing or ditch the housing. I will use the open barrel crimps on small awg 22 and smaller if I must, but I don't consider them suitable for 18 awg or larger unless soldered and that has other issues associated. Ken Robert L. Nuckolls, III wrote: > > > At 03:50 AM 3/25/2008 -0600, you wrote: > >> >> Hello all, >> >> I'm fabricating a new harness for my voltage regulator (Zeftronics >> regulator for a Cessna) and am searching for a supplier of uninsulated >> 0.25" female fast-on terminals that have a small tab sticking out of >> the 'back' that will lock them inside the plastic backshell. I've >> checked the Mouser, Newark, B&C, Waytek, and Allied catalogs without >> luck. However, perhaps I'm not using the correct keyword to find >> these oddball terminals in their search engines. Perhaps an autoparts >> store would carry them (the original Cessna regulator was a Ford part, >> I believe)? >> >> Thanks for any suggestions you folks can provide. > > I've never found these as loose fabrication or repair > parts . . . but that doesn't mean somebody doesn't have > them. Most builders use individual fast-on terminals > and ditch the housing. You can buy the housing with > terminals installed and short pig-tails at some care > parts stores. I think I've seen them in the red "Help" > line of blister-packed, peg-board products. > > I can get you a part number for a reel of 5,000! B&C > used to have some that were used with the housing that > fits the connector on the back of an alternator. These > were bare-brass (un-plated) parts. They might work with > your regulator tabs connector housing. I'd go with the > loose PIDG fast-on terminals and ditch the housing. > > Bob . . . ________________________________ Message 9 _____________________________________ Time: 11:08:39 AM PST US From: "Don Curry" Subject: AeroElectric-List: WX-500 Install Manual Would anyone happen to know where I could obtain a WX-500 Install Manual? Don ________________________________ Message 10 ____________________________________ Time: 01:13:35 PM PST US From: "Scott R. Shook" Subject: AeroElectric-List: Question about Resistors Bob et al, I am putting together an annunciator panel using some Stanley LED Light Bars PN# (404-1148-ND). And if I read correctly on the spec sheet from Digikey, the voltage is 1.7v per LED. This being the case, do you have a 'cheat sheet' showing what resistors I would need to provide the appropriate voltage drop for our 14v OBAM aircraft? Scott R. Shook RV-7A (Building) N696JS (Reserved) ________________________________ Message 11 ____________________________________ Time: 01:45:25 PM PST US From: "Carl Morgan" Subject: RE: AeroElectric-List: B&C SD-20 and magnetic interference Hi Bob, Removing the 'whiskey compass' could / will result in my aircraft being grounded. I have been round the loop with the NZ CAA and the 'need' for a traditional compass, I already have a GRT EFIS with magnetometer, IFR GPS and still not enough. At the moment it is going to be an up cliff paperwork struggle. Removing the SD-20 is a 'better' option from their perspective, but with a full FADEC I'm not comfortable with just dual battery, single alternator - and having got to this point where the engine is running great (or too well) removing the SD-20 isn't an option either. Distance changing is going to be in the order of 1" difference, unless I mounted it in the baggage compartment. What options can be used to reduce the magnetic impact - is it a luck of the draw with the SD-20 - ie. they all vary abit? We are only taking 3-4 amps under normal operations. I understand some interference coming out, but what is 'too much'? WRT: > This is NOT a downside checkmark on the blackboard > for the B&C SD-20. ALL alternators have a steel > shaft that runs through the device parallel > to the magnetic lines of force generated in > the field windings. My biggest complaint is there is NO indication or warnings about this anywhere in the instruction / website information - I would have reconsidered the panel layout with this information, as it is I'm fixed without major rework and it is affecting my Autopilot backup and one of the few instruments the regulator is specifically interested in.... How can I reduce this interference at the source - hopefully a small reduction will be enough to get calibration within spec. Thanks, Carl -- Carl Morgan - ZK-VII - RV 7A http://www.rvproject.gen.nz/ > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of > Robert L. Nuckolls, III > Sent: 26 March 2008 00:12 > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: B&C SD-20 and magnetic interference > > > III" > > At 09:44 AM 3/25/2008 +1300, you wrote: > > > > > > >Hi, > > > >We have been running for about 20 hours now chasing different > problems. One > >outstanding one is magnetic interference from the SD-20 / LR3 > combination. > >We have a TSO'd vertical card compass (and yes it is a southern > hemisphere > >model) mounted in the middle of the panel area (center/center). > We are dual > >alt / dual bus configuration. > > > >When the field wire is connected to the SD-20 (lower connection) > we get up > >to 40 degree swing on the compass - it does vary in amount (from 20-40 > >degrees) based on direction - south seems the worst. Pulling the field > >breaker causes it swings back about 30 degrees, but the > regulator / alt are > >still have an affect. > > > >B&C are saying some swing is 'normal' - but 40 degrees - I'm > struggling! I > >can't calibrate that much out (best effort so far is +- 15 degrees). > > > >I've tried changing the location / orientation of the regulator - no > >difference. I've tried moving another wet compass around the panel / > >cockpit - it looks like same problem (although a bit hard to tell). > > > >I've tried running some grounded braid around the firewall > forward side of > >the field wire - no change. Same symptoms on ground, air, zero > RPM and full > >power. There may be a small movement (< 3 degrees) based on current draw > >from SD-20. With SD-20 field disconnected and X-Feed in - no movement. > > > >Questions: > > a) Have others got this / solved this? > > b) Any suggested methods of screening the SD-20? > > > >Thanks, > > > >Carl > > > The problem is magnetic, not electrical. > Had this problem on the Bonanza too. The SD-20 > (as do most alternators) has a considerable > leakage of magnetic flux from the rotor winding. > This isn't a problem for most installations > where the alternator mounts on the front of > the engine. > > Alternators hung on the rear of the engine > are much closer to the instrument panel and > more likely to be an issue with a panel > mounted compass. > > In the Bonanza, we moved the compass off the > glareshield to a location on higher on the > windshield. Adding a magnetic shield around > the SD-20 is a pretty busy task. The shield > material would have to be magnetic and cover > the rear and perhaps the circumference of the > alternator. This has some issues with cooling, > wiring egress and labor to implement it. > > The easiest fix is to increase distance between > the compass and the alternator. Magnetic > 'radiation' is a weak propagator . . . a little > distance really helps. > > Alternatively, an electronic compass with > a remote sensor out in a wing is the best > way to achieve the highest performance > in a magnetic direction indicator. The > case can be made that since you have > 3 sources of DC power, reliability of > the electronic compass is assured. I would > also hope that you carry a hand-held GPS > in the flight bag too. > > I'm not sure I'd bother to install a > whisky compass any more. Likelihood of > ever needing one these days is about nil. > Same thing happened to buggy whips. We > were fortunate not to be plagued by the > FHA (Federal Horsecart Administration) > when the transition occurred. Hmmmm . . . > maybe they didn't really go away . . . > they just morphed into radio antennas. > > Let's be really clear about this condition. > This is NOT a downside checkmark on the blackboard > for the B&C SD-20. ALL alternators have a steel > shaft that runs through the device parallel > to the magnetic lines of force generated in > the field windings. See: > > http://www.aeroelectric.com/Pictures/Alternators/Alternator_w_Inte > rnal_Fan2.gif > > This mechanical feature insures that EVERY > alternator will present a strong external > magnetic field. It's a system integration problem > that seldom presents but has multiple solutions > for maintaining flight-system reliability. The > REAL problem is getting those-who-know-more- > about-airplanes-than-we-do to join us in > the 21st century. > > Bob . . . > > > Checked by AVG. > 25/03/2008 10:26 > Checked by AVG. 10:26 ________________________________ Message 12 ____________________________________ Time: 02:31:22 PM PST US From: "Bryan" Subject: AeroElectric-List: Alternator I have a 12V 60A Chrysler alternator that came with the engine I am rebuilding. Unfortunately I do not have the brackets for this alternator. Does anyone know where to get brackets for a reasonable price (I don't even know what part number), or would I be better off just going with a Plane Power kit? Thanks Bryan ________________________________ Message 13 ____________________________________ Time: 03:51:05 PM PST US From: "Vernon Little" Subject: RE: AeroElectric-List: Question about Resistors Hi Scott: Here's the formula: R = (Vbatt-Vf)/If ohms, where Vf is 1.7 V and If is 20 ma (from datasheet) For the part you chose, R = (14.2-1.7)/0.020 = 625 ohms (use 680 ohm standard value) -- if you power each segment seperately. If you connect all 5 of the LEDs in series, then R = (14.2 - 5*1.7)/0.020 285 ohms (use 330 ohm standard value). Now, here's one issue to deal with: If you are dimming the LEDs, you may want to power each segment separately so that they dim the same as other displays in the cockpit. Only experimentation will give you the answer for this. Finally, you may want to try one light bar first before you commit to using them in a panel. They may have a tendency to wash out in bright sunlight. I used to sell a product line that used similar light bars, and this was an issue unless you carefully shield the display from ambient light (such as locating right underneath the glareshield). I found some 1/8" LEDs that will dazzle your eyes, but they were very difficult to dim due to their intensity. Of course, they were tiny and not easy to label!. Good luck. Vern Little. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Scott R. Shook Sent: March 25, 2008 12:59 PM Subject: AeroElectric-List: Question about Resistors Bob et al, I am putting together an annunciator panel using some Stanley LED Light Bars PN# (404-1148-ND). And if I read correctly on the spec sheet from Digikey, the voltage is 1.7v per LED. This being the case, do you have a 'cheat sheet' showing what resistors I would need to provide the appropriate voltage drop for our 14v OBAM aircraft? Scott R. Shook RV-7A (Building) N696JS (Reserved) ________________________________ Message 14 ____________________________________ Time: 04:07:07 PM PST US Subject: RE: AeroElectric-List: B&C SD-20 and magnetic interference From: "Matt Prather" Are _you_ concerned about the function of the whiskey compass? If not (given the other equipment on board), do your best to come up with a calibration card for it and call it good. Side question.. I got the impression that your compass reads accurately when the field is turned off on the SD-20. Can the SD-20 be used only when your main alternator is off line? If so, the only time your compass will have a problem is if the main alternator fails. I could live with that.. Also, what's the wire routing of the output and field of the SD-20 (with respect to the compass? Is it possible that the wire routing is contributing to the B-field generated by the SD-20? Is the ground following a different route than the field and output wires? I'm pretty sure Bob's assessment of the cause of your headache was correct, but I wonder if there might be additional factors... In a different direction, you can get a remote compass from Century Instruments: http://www.trade-a-plane.com/dispads/0000769074.pdf Kinda spendy at $500 for the kit.. And, I don't know if it actually satisfies the requirement. Regards, Matt- > > > Hi Bob, > > Removing the 'whiskey compass' could / will result in my aircraft being > grounded. I have been round the loop with the NZ CAA and the 'need' for a > traditional compass, I already have a GRT EFIS with magnetometer, IFR GPS > and still not enough. At the moment it is going to be an up cliff > paperwork > struggle. > > Removing the SD-20 is a 'better' option from their perspective, but with a > full FADEC I'm not comfortable with just dual battery, single alternator - > and having got to this point where the engine is running great (or too > well) > removing the SD-20 isn't an option either. Distance changing is going to > be > in the order of 1" difference, unless I mounted it in the baggage > compartment. What options can be used to reduce the magnetic impact - is > it > a luck of the draw with the SD-20 - ie. they all vary abit? We are only > taking 3-4 amps under normal operations. I understand some interference > coming out, but what is 'too much'? > > WRT: >> This is NOT a downside checkmark on the blackboard >> for the B&C SD-20. ALL alternators have a steel >> shaft that runs through the device parallel >> to the magnetic lines of force generated in >> the field windings. > > My biggest complaint is there is NO indication or warnings about this > anywhere in the instruction / website information - I would have > reconsidered the panel layout with this information, as it is I'm fixed > without major rework and it is affecting my Autopilot backup and one of > the > few instruments the regulator is specifically interested in.... > > How can I reduce this interference at the source - hopefully a small > reduction will be enough to get calibration within spec. > > Thanks, > > Carl > -- > Carl Morgan - ZK-VII - RV 7A > http://www.rvproject.gen.nz/ > >> -----Original Message----- >> From: owner-aeroelectric-list-server@matronics.com >> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of >> Robert L. Nuckolls, III >> Sent: 26 March 2008 00:12 >> To: aeroelectric-list@matronics.com >> Subject: Re: AeroElectric-List: B&C SD-20 and magnetic interference >> >> >> III" >> >> At 09:44 AM 3/25/2008 +1300, you wrote: >> >> > >> > >> >Hi, >> > >> >We have been running for about 20 hours now chasing different >> problems. One >> >outstanding one is magnetic interference from the SD-20 / LR3 >> combination. >> >We have a TSO'd vertical card compass (and yes it is a southern >> hemisphere >> >model) mounted in the middle of the panel area (center/center). >> We are dual >> >alt / dual bus configuration. >> > >> >When the field wire is connected to the SD-20 (lower connection) >> we get up >> >to 40 degree swing on the compass - it does vary in amount (from 20-40 >> >degrees) based on direction - south seems the worst. Pulling the field >> >breaker causes it swings back about 30 degrees, but the >> regulator / alt are >> >still have an affect. >> > >> >B&C are saying some swing is 'normal' - but 40 degrees - I'm >> struggling! I >> >can't calibrate that much out (best effort so far is +- 15 degrees). >> > >> >I've tried changing the location / orientation of the regulator - no >> >difference. I've tried moving another wet compass around the panel / >> >cockpit - it looks like same problem (although a bit hard to tell). >> > >> >I've tried running some grounded braid around the firewall >> forward side of >> >the field wire - no change. Same symptoms on ground, air, zero >> RPM and full >> >power. There may be a small movement (< 3 degrees) based on current >> draw >> >from SD-20. With SD-20 field disconnected and X-Feed in - no movement. >> > >> >Questions: >> > a) Have others got this / solved this? >> > b) Any suggested methods of screening the SD-20? >> > >> >Thanks, >> > >> >Carl >> >> >> The problem is magnetic, not electrical. >> Had this problem on the Bonanza too. The SD-20 >> (as do most alternators) has a considerable >> leakage of magnetic flux from the rotor winding. >> This isn't a problem for most installations >> where the alternator mounts on the front of >> the engine. >> >> Alternators hung on the rear of the engine >> are much closer to the instrument panel and >> more likely to be an issue with a panel >> mounted compass. >> >> In the Bonanza, we moved the compass off the >> glareshield to a location on higher on the >> windshield. Adding a magnetic shield around >> the SD-20 is a pretty busy task. The shield >> material would have to be magnetic and cover >> the rear and perhaps the circumference of the >> alternator. This has some issues with cooling, >> wiring egress and labor to implement it. >> >> The easiest fix is to increase distance between >> the compass and the alternator. Magnetic >> 'radiation' is a weak propagator . . . a little >> distance really helps. >> >> Alternatively, an electronic compass with >> a remote sensor out in a wing is the best >> way to achieve the highest performance >> in a magnetic direction indicator. The >> case can be made that since you have >> 3 sources of DC power, reliability of >> the electronic compass is assured. I would >> also hope that you carry a hand-held GPS >> in the flight bag too. >> >> I'm not sure I'd bother to install a >> whisky compass any more. Likelihood of >> ever needing one these days is about nil. >> Same thing happened to buggy whips. We >> were fortunate not to be plagued by the >> FHA (Federal Horsecart Administration) >> when the transition occurred. Hmmmm . . . >> maybe they didn't really go away . . . >> they just morphed into radio antennas. >> >> Let's be really clear about this condition. >> This is NOT a downside checkmark on the blackboard >> for the B&C SD-20. ALL alternators have a steel >> shaft that runs through the device parallel >> to the magnetic lines of force generated in >> the field windings. See: >> >> http://www.aeroelectric.com/Pictures/Alternators/Alternator_w_Inte >> rnal_Fan2.gif >> >> This mechanical feature insures that EVERY >> alternator will present a strong external >> magnetic field. It's a system integration problem >> that seldom presents but has multiple solutions >> for maintaining flight-system reliability. The >> REAL problem is getting those-who-know-more- >> about-airplanes-than-we-do to join us in >> the 21st century. >> >> Bob . . . >> >> >> >> >> >> Checked by AVG. >> 25/03/2008 10:26 >> > Checked by AVG. > 10:26 > > ________________________________ Message 15 ____________________________________ Time: 04:13:31 PM PST US Subject: AeroElectric-List: KX-155 Audio Out From: "txpilot" I have a KX-155 and a Sigtronics Sport 200 intercom. I'm trying to figure out the proper wiring between units. The KX-155 has an 'audio hi' and 'audio lo' for both the comm and nav. I'm confused what is meant with the 'hi' and 'lo'. Are the 'audio hi' connections supposed to go to the common blue intercom wire, common with the headset jacks, while the 'audio lo' connections go to ground? If that's the case, why must the 'audio lo' connections be shielded if it's going to ground anyway? Thanks for your help! Dan Ginty Read this topic online here: http://forums.matronics.com/viewtopic.php?p=172651#172651 ________________________________ Message 16 ____________________________________ Time: 04:41:01 PM PST US From: "RALPH HOOVER" Subject: RE: AeroElectric-List: Question about Resistors Scott, You need to drop 12.3V (14-1.7) while limiting the current to ~20ma R=E/I (12.3/.02 = 615 Ohms). The power dissipated will be P=I*E (.02*12.3=.246 watts). A 620 ohm 1/2W resistor would be fine for 1 LED. If you connect several LED's in series subtract the total voltage drop and do the same calculation. 14-3.4 for 2 and so on. LED's will work over a fairly broad range of current depending on the type and brightness desired so don't worry too much about exact resistor values. You can work backwards to find the current I=E/R so if you use 560 ohms (12.3/560=.022) or 22ma. Check your Digikey catalog for standard resistor values. Good luck _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Scott R. Shook Sent: Tuesday, March 25, 2008 2:59 PM Subject: AeroElectric-List: Question about Resistors Bob et al, I am putting together an annunciator panel using some Stanley LED Light Bars PN# (404-1148-ND). And if I read correctly on the spec sheet from Digikey, the voltage is 1.7v per LED. This being the case, do you have a 'cheat sheet' showing what resistors I would need to provide the appropriate voltage drop for our 14v OBAM aircraft? Scott R. Shook RV-7A (Building) N696JS (Reserved) ________________________________ Message 17 ____________________________________ Time: 04:51:47 PM PST US From: "RALPH HOOVER" Subject: RE: AeroElectric-List: oddball 0.25" fast-on terminal source? D, I had the same issue and bought a roll of AMP tin plated for 18-22 AWG wire. DigiKey P/N A27933CT-ND AMP P/N 60295-2 If these will help send me your address off list and I will mail you a few. I bought 100 and needed 3 :( I just couldn't think of butt splices on the Alternator wires. Hooverra at verizon dot net Ralph -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of D Wysong Sent: Tuesday, March 25, 2008 4:50 AM Subject: AeroElectric-List: oddball 0.25" fast-on terminal source? Hello all, I'm fabricating a new harness for my voltage regulator (Zeftronics regulator for a Cessna) and am searching for a supplier of uninsulated 0.25" female fast-on terminals that have a small tab sticking out of the 'back' that will lock them inside the plastic backshell. I've checked the Mouser, Newark, B&C, Waytek, and Allied catalogs without luck. However, perhaps I'm not using the correct keyword to find these oddball terminals in their search engines. Perhaps an autoparts store would carry them (the original Cessna regulator was a Ford part, I believe)? Thanks for any suggestions you folks can provide. D ________________________________ Message 18 ____________________________________ Time: 04:54:08 PM PST US From: "n801bh@netzero.com" Subject: Re: AeroElectric-List: KX-155 Audio Out I got tripped up on that term when I was wiring my experimental too. I h ave wired alot of car radios and other stuff growing up so the Hi/ Lo t hing seemed strange. Someone on this list straightened me out. The HI is really the hot wire or feed, the Low is just the ground. Why they don't call it that is beyond me.. do not archive Ben Haas N801BH www.haaspowerair.com -- "txpilot" wrote: I have a KX-155 and a Sigtronics Sport 200 intercom. I'm trying to figu re out the proper wiring between units. The KX-155 has an 'audio hi' an d 'audio lo' for both the comm and nav. I'm confused what is meant with the 'hi' and 'lo'. Are the 'audio hi' connections supposed to go to the common blue interco m wire, common with the headset jacks, while the 'audio lo' connections go to ground? If that's the case, why must the 'audio lo' connections b e shielded if it's going to ground anyway? Thanks for your help! Dan Ginty Read this topic online here: http://forums.matronics.com/viewtopic.php?p=172651#172651 ======================== =========== ======================== =========== ======================== =========== ======================== =========== _____________________________________________________________ Click here to find single Christians that want to meet you today. http://thirdpartyoffers.netzero.net/TGL2221/fc/Ioyw6i4ub6MbtwNC3uMRXX8FR P9iZUPZ5ToUiyoDQEL6kvbYSpX69z/ ________________________________ Message 19 ____________________________________ Time: 04:54:28 PM PST US From: "Carl Morgan" Subject: RE: AeroElectric-List: B&C SD-20 and magnetic interference Hi Matt, Thanks for the ideas, I'm really not that concerned about the whiskey compass functionality - if I've lost all my other mag direction indicators - the engine has stopped, so I don't really care about direction ;-) However the CAA so far is and the calibration card per regs has to be within 10 degrees :-(. SD-20 off / disconnected - yes I think the compass reads right - but we are dual bus (two independent active buses), not endurance / essential bus - so both alts need to be running / working. Wire routing - the B lead and field goes aft from the SD-20 to the firewall, left across the top of the firewall, aft again through the firewall and back to a mid location for the regulator which is on a tray between the forward panel ribs (RV 7A Tipup). Remote compass - it could yet be the option - but I don't like to even think about the routing of the cables through the tunnel / spar / wing..... Regards, Carl -- Carl Morgan - ZK-VII - RV 7A http://www.rvproject.gen.nz/ > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Matt > Prather > Sent: 26 March 2008 11:59 > To: aeroelectric-list@matronics.com > Subject: RE: AeroElectric-List: B&C SD-20 and magnetic interference > > > > > Are _you_ concerned about the function of the whiskey compass? If not > (given the other equipment on board), do your best to come up with a > calibration card for it and call it good. > > Side question.. I got the impression that your compass reads accurately > when the field is turned off on the SD-20. Can the SD-20 be used only > when your main alternator is off line? If so, the only time your compass > will have a problem is if the main alternator fails. I could live with > that.. > > Also, what's the wire routing of the output and field of the SD-20 (with > respect to the compass? Is it possible that the wire routing is > contributing to the B-field generated by the SD-20? Is the ground > following a different route than the field and output wires? I'm pretty > sure Bob's assessment of the cause of your headache was correct, but I > wonder if there might be additional factors... > > In a different direction, you can get a remote compass from Century > Instruments: > > http://www.trade-a-plane.com/dispads/0000769074.pdf > > Kinda spendy at $500 for the kit.. And, I don't know if it actually > satisfies the requirement. > > > Regards, > > Matt- > > > > > > > Hi Bob, > > > > Removing the 'whiskey compass' could / will result in my aircraft being > > grounded. I have been round the loop with the NZ CAA and the > 'need' for a > > traditional compass, I already have a GRT EFIS with > magnetometer, IFR GPS > > and still not enough. At the moment it is going to be an up cliff > > paperwork > > struggle. > > > > Removing the SD-20 is a 'better' option from their perspective, > but with a > > full FADEC I'm not comfortable with just dual battery, single > alternator - > > and having got to this point where the engine is running great (or too > > well) > > removing the SD-20 isn't an option either. Distance changing > is going to > > be > > in the order of 1" difference, unless I mounted it in the baggage > > compartment. What options can be used to reduce the magnetic > impact - is > > it > > a luck of the draw with the SD-20 - ie. they all vary abit? We are only > > taking 3-4 amps under normal operations. I understand some interference > > coming out, but what is 'too much'? > > > > WRT: > >> This is NOT a downside checkmark on the blackboard > >> for the B&C SD-20. ALL alternators have a steel > >> shaft that runs through the device parallel > >> to the magnetic lines of force generated in > >> the field windings. > > > > My biggest complaint is there is NO indication or warnings about this > > anywhere in the instruction / website information - I would have > > reconsidered the panel layout with this information, as it is I'm fixed > > without major rework and it is affecting my Autopilot backup and one of > > the > > few instruments the regulator is specifically interested in.... > > > > How can I reduce this interference at the source - hopefully a small > > reduction will be enough to get calibration within spec. > > > > Thanks, > > > > Carl > > -- > > Carl Morgan - ZK-VII - RV 7A > > http://www.rvproject.gen.nz/ > > > >> -----Original Message----- > >> From: owner-aeroelectric-list-server@matronics.com > >> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of > >> Robert L. Nuckolls, III > >> Sent: 26 March 2008 00:12 > >> To: aeroelectric-list@matronics.com > >> Subject: Re: AeroElectric-List: B&C SD-20 and magnetic interference > >> > >> > >> III" > >> > >> At 09:44 AM 3/25/2008 +1300, you wrote: > >> > >> > > >> > > >> >Hi, > >> > > >> >We have been running for about 20 hours now chasing different > >> problems. One > >> >outstanding one is magnetic interference from the SD-20 / LR3 > >> combination. > >> >We have a TSO'd vertical card compass (and yes it is a southern > >> hemisphere > >> >model) mounted in the middle of the panel area (center/center). > >> We are dual > >> >alt / dual bus configuration. > >> > > >> >When the field wire is connected to the SD-20 (lower connection) > >> we get up > >> >to 40 degree swing on the compass - it does vary in amount (from 20-40 > >> >degrees) based on direction - south seems the worst. Pulling > the field > >> >breaker causes it swings back about 30 degrees, but the > >> regulator / alt are > >> >still have an affect. > >> > > >> >B&C are saying some swing is 'normal' - but 40 degrees - I'm > >> struggling! I > >> >can't calibrate that much out (best effort so far is +- 15 degrees). > >> > > >> >I've tried changing the location / orientation of the regulator - no > >> >difference. I've tried moving another wet compass around the panel / > >> >cockpit - it looks like same problem (although a bit hard to tell). > >> > > >> >I've tried running some grounded braid around the firewall > >> forward side of > >> >the field wire - no change. Same symptoms on ground, air, zero > >> RPM and full > >> >power. There may be a small movement (< 3 degrees) based on current > >> draw > >> >from SD-20. With SD-20 field disconnected and X-Feed in - no > movement. > >> > > >> >Questions: > >> > a) Have others got this / solved this? > >> > b) Any suggested methods of screening the SD-20? > >> > > >> >Thanks, > >> > > >> >Carl > >> > >> > >> The problem is magnetic, not electrical. > >> Had this problem on the Bonanza too. The SD-20 > >> (as do most alternators) has a considerable > >> leakage of magnetic flux from the rotor winding. > >> This isn't a problem for most installations > >> where the alternator mounts on the front of > >> the engine. > >> > >> Alternators hung on the rear of the engine > >> are much closer to the instrument panel and > >> more likely to be an issue with a panel > >> mounted compass. > >> > >> In the Bonanza, we moved the compass off the > >> glareshield to a location on higher on the > >> windshield. Adding a magnetic shield around > >> the SD-20 is a pretty busy task. The shield > >> material would have to be magnetic and cover > >> the rear and perhaps the circumference of the > >> alternator. This has some issues with cooling, > >> wiring egress and labor to implement it. > >> > >> The easiest fix is to increase distance between > >> the compass and the alternator. Magnetic > >> 'radiation' is a weak propagator . . . a little > >> distance really helps. > >> > >> Alternatively, an electronic compass with > >> a remote sensor out in a wing is the best > >> way to achieve the highest performance > >> in a magnetic direction indicator. The > >> case can be made that since you have > >> 3 sources of DC power, reliability of > >> the electronic compass is assured. I would > >> also hope that you carry a hand-held GPS > >> in the flight bag too. > >> > >> I'm not sure I'd bother to install a > >> whisky compass any more. Likelihood of > >> ever needing one these days is about nil. > >> Same thing happened to buggy whips. We > >> were fortunate not to be plagued by the > >> FHA (Federal Horsecart Administration) > >> when the transition occurred. Hmmmm . . . > >> maybe they didn't really go away . . . > >> they just morphed into radio antennas. > >> > >> Let's be really clear about this condition. > >> This is NOT a downside checkmark on the blackboard > >> for the B&C SD-20. ALL alternators have a steel > >> shaft that runs through the device parallel > >> to the magnetic lines of force generated in > >> the field windings. See: > >> > >> http://www.aeroelectric.com/Pictures/Alternators/Alternator_w_Inte > >> rnal_Fan2.gif > >> > >> This mechanical feature insures that EVERY > >> alternator will present a strong external > >> magnetic field. It's a system integration problem > >> that seldom presents but has multiple solutions > >> for maintaining flight-system reliability. The > >> REAL problem is getting those-who-know-more- > >> about-airplanes-than-we-do to join us in > >> the 21st century. > >> > >> Bob . . . > >> > >> > >> > >> > >> > >> Checked by AVG. > >> 25/03/2008 10:26 > >> > > Checked by AVG. > > 10:26 > > > > > > > > > > > > > > > Checked by AVG. > 25/03/2008 10:26 > Checked by AVG. 10:26 ________________________________ Message 20 ____________________________________ Time: 05:08:48 PM PST US From: "Scott R. Shook" Subject: RE: AeroElectric-List: Question about Resistors That is the formula I was looking for. Thank you. The light bars themselves, have 5 LED's so those will go in a series. My last trick will be mounting them and the wiring of said LED's. I am hoping a blank project circuit board will do what I want. The trick with the circuit board will be the spacing requirements (space between light bars). Once that is figured, I can order the face (reverse engraved acrylic). I am also working on a "push-to test" option. As far as the intensity, since these will be behind a reverse engraved acrylic (black behind clear) only the letters themselves will light up. Once I get the mock up completed, the day/night intensity testing will be performed. Scott R. Shook RV-7A (Building) N696JS (Reserved) _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Vernon Little Sent: Tuesday, 25 March, 2008 15:46 Subject: RE: AeroElectric-List: Question about Resistors Hi Scott: Here's the formula: R = (Vbatt-Vf)/If ohms, where Vf is 1.7 V and If is 20 ma (from datasheet) For the part you chose, R = (14.2-1.7)/0.020 = 625 ohms (use 680 ohm standard value) -- if you power each segment seperately. If you connect all 5 of the LEDs in series, then R = (14.2 - 5*1.7)/0.020 285 ohms (use 330 ohm standard value). Now, here's one issue to deal with: If you are dimming the LEDs, you may want to power each segment separately so that they dim the same as other displays in the cockpit. Only experimentation will give you the answer for this. Finally, you may want to try one light bar first before you commit to using them in a panel. They may have a tendency to wash out in bright sunlight. I used to sell a product line that used similar light bars, and this was an issue unless you carefully shield the display from ambient light (such as locating right underneath the glareshield). I found some 1/8" LEDs that will dazzle your eyes, but they were very difficult to dim due to their intensity. Of course, they were tiny and not easy to label!. Good luck. Vern Little. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Scott R. Shook Sent: March 25, 2008 12:59 PM Subject: AeroElectric-List: Question about Resistors Bob et al, I am putting together an annunciator panel using some Stanley LED Light Bars PN# (404-1148-ND). And if I read correctly on the spec sheet from Digikey, the voltage is 1.7v per LED. This being the case, do you have a 'cheat sheet' showing what resistors I would need to provide the appropriate voltage drop for our 14v OBAM aircraft? Scott R. Shook RV-7A (Building) N696JS (Reserved) href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matro nics.com/Navigator?AeroElectric-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ________________________________ Message 21 ____________________________________ Time: 06:21:52 PM PST US From: Kevin Horton Subject: Re: AeroElectric-List: B&C SD-20 and magnetic interference There are type certificated aircraft where the whiskey compass is only accurate in a very particular electrical system configuration. For example, on the Cessna C550 (Citation II business jet), the whiskey compass is only useable if both generators are OFF. This is quite acceptable to the FAA, Transport Canada, and I presume the NZ CAA. Given that you have an EFIS with a remote flux valve that acts as your primary source of magnetic heading, you don't need the whiskey compass to read accurately most of the time. I wonder if it might be acceptable to put a placard by the whiskey compass that said "SD-20 Alternator must be OFF to use compass". Then make a compass correction card that is only valid if the SD-20 is OFF. Kevin Horton On 25 Mar 2008, at 19:51, Carl Morgan wrote: > vii@rvproject.gen.nz> > > Hi Matt, > > Thanks for the ideas, I'm really not that concerned about the whiskey > compass functionality - if I've lost all my other mag direction > indicators - > the engine has stopped, so I don't really care about direction ;-) > However > the CAA so far is and the calibration card per regs has to be > within 10 > degrees :-(. > > SD-20 off / disconnected - yes I think the compass reads right - > but we are > dual bus (two independent active buses), not endurance / essential > bus - so > both alts need to be running / working. > > Wire routing - the B lead and field goes aft from the SD-20 to the > firewall, > left across the top of the firewall, aft again through the firewall > and back > to a mid location for the regulator which is on a tray between the > forward > panel ribs (RV 7A Tipup). > > Remote compass - it could yet be the option - but I don't like to > even think > about the routing of the cables through the tunnel / spar / wing..... > > Regards, > > Carl > -- > Carl Morgan - ZK-VII - RV 7A > http://www.rvproject.gen.nz/ > >> -----Original Message----- >> From: owner-aeroelectric-list-server@matronics.com >> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of >> Matt >> Prather >> Sent: 26 March 2008 11:59 >> To: aeroelectric-list@matronics.com >> Subject: RE: AeroElectric-List: B&C SD-20 and magnetic interference >> >> >> >> >> Are _you_ concerned about the function of the whiskey compass? If >> not >> (given the other equipment on board), do your best to come up with a >> calibration card for it and call it good. >> >> Side question.. I got the impression that your compass reads >> accurately >> when the field is turned off on the SD-20. Can the SD-20 be used >> only >> when your main alternator is off line? If so, the only time your >> compass >> will have a problem is if the main alternator fails. I could live >> with >> that.. >> >> Also, what's the wire routing of the output and field of the SD-20 >> (with >> respect to the compass? Is it possible that the wire routing is >> contributing to the B-field generated by the SD-20? Is the ground >> following a different route than the field and output wires? I'm >> pretty >> sure Bob's assessment of the cause of your headache was correct, >> but I >> wonder if there might be additional factors... >> >> In a different direction, you can get a remote compass from Century >> Instruments: >> >> http://www.trade-a-plane.com/dispads/0000769074.pdf >> >> Kinda spendy at $500 for the kit.. And, I don't know if it actually >> satisfies the requirement. >> >> >> Regards, >> >> Matt- >> >>> >>> >>> Hi Bob, >>> >>> Removing the 'whiskey compass' could / will result in my aircraft >>> being >>> grounded. I have been round the loop with the NZ CAA and the >> 'need' for a >>> traditional compass, I already have a GRT EFIS with >> magnetometer, IFR GPS >>> and still not enough. At the moment it is going to be an up cliff >>> paperwork >>> struggle. >>> >>> Removing the SD-20 is a 'better' option from their perspective, >> but with a >>> full FADEC I'm not comfortable with just dual battery, single >> alternator - >>> and having got to this point where the engine is running great >>> (or too >>> well) >>> removing the SD-20 isn't an option either. Distance changing >> is going to >>> be >>> in the order of 1" difference, unless I mounted it in the baggage >>> compartment. What options can be used to reduce the magnetic >> impact - is >>> it >>> a luck of the draw with the SD-20 - ie. they all vary abit? We >>> are only >>> taking 3-4 amps under normal operations. I understand some >>> interference >>> coming out, but what is 'too much'? >>> >>> WRT: >>>> This is NOT a downside checkmark on the blackboard >>>> for the B&C SD-20. ALL alternators have a steel >>>> shaft that runs through the device parallel >>>> to the magnetic lines of force generated in >>>> the field windings. >>> >>> My biggest complaint is there is NO indication or warnings about >>> this >>> anywhere in the instruction / website information - I would have >>> reconsidered the panel layout with this information, as it is I'm >>> fixed >>> without major rework and it is affecting my Autopilot backup and >>> one of >>> the >>> few instruments the regulator is specifically interested in.... >>> >>> How can I reduce this interference at the source - hopefully a small >>> reduction will be enough to get calibration within spec. >>> >>> Thanks, >>> >>> Carl >>> -- >>> Carl Morgan - ZK-VII - RV 7A >>> http://www.rvproject.gen.nz/ >>> >>>> -----Original Message----- >>>> From: owner-aeroelectric-list-server@matronics.com >>>> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of >>>> Robert L. Nuckolls, III >>>> Sent: 26 March 2008 00:12 >>>> To: aeroelectric-list@matronics.com >>>> Subject: Re: AeroElectric-List: B&C SD-20 and magnetic interference >>>> >>>> >>>> III" >>>> >>>> At 09:44 AM 3/25/2008 +1300, you wrote: >>>> >>>>> >>>>> >>>>> Hi, >>>>> >>>>> We have been running for about 20 hours now chasing different >>>> problems. One >>>>> outstanding one is magnetic interference from the SD-20 / LR3 >>>> combination. >>>>> We have a TSO'd vertical card compass (and yes it is a southern >>>> hemisphere >>>>> model) mounted in the middle of the panel area (center/center). >>>> We are dual >>>>> alt / dual bus configuration. >>>>> >>>>> When the field wire is connected to the SD-20 (lower connection) >>>> we get up >>>>> to 40 degree swing on the compass - it does vary in amount >>>>> (from 20-40 >>>>> degrees) based on direction - south seems the worst. Pulling >> the field >>>>> breaker causes it swings back about 30 degrees, but the >>>> regulator / alt are >>>>> still have an affect. >>>>> >>>>> B&C are saying some swing is 'normal' - but 40 degrees - I'm >>>> struggling! I >>>>> can't calibrate that much out (best effort so far is +- 15 >>>>> degrees). >>>>> >>>>> I've tried changing the location / orientation of the regulator >>>>> - no >>>>> difference. I've tried moving another wet compass around the >>>>> panel / >>>>> cockpit - it looks like same problem (although a bit hard to >>>>> tell). >>>>> >>>>> I've tried running some grounded braid around the firewall >>>> forward side of >>>>> the field wire - no change. Same symptoms on ground, air, zero >>>> RPM and full >>>>> power. There may be a small movement (< 3 degrees) based on >>>>> current >>>> draw >>>>> from SD-20. With SD-20 field disconnected and X-Feed in - no >> movement. >>>>> >>>>> Questions: >>>>> a) Have others got this / solved this? >>>>> b) Any suggested methods of screening the SD-20? >>>>> >>>>> Thanks, >>>>> >>>>> Carl >>>> >>>> >>>> The problem is magnetic, not electrical. >>>> Had this problem on the Bonanza too. The SD-20 >>>> (as do most alternators) has a considerable >>>> leakage of magnetic flux from the rotor winding. >>>> This isn't a problem for most installations >>>> where the alternator mounts on the front of >>>> the engine. >>>> >>>> Alternators hung on the rear of the engine >>>> are much closer to the instrument panel and >>>> more likely to be an issue with a panel >>>> mounted compass. >>>> >>>> In the Bonanza, we moved the compass off the >>>> glareshield to a location on higher on the >>>> windshield. Adding a magnetic shield around >>>> the SD-20 is a pretty busy task. The shield >>>> material would have to be magnetic and cover >>>> the rear and perhaps the circumference of the >>>> alternator. This has some issues with cooling, >>>> wiring egress and labor to implement it. >>>> >>>> The easiest fix is to increase distance between >>>> the compass and the alternator. Magnetic >>>> 'radiation' is a weak propagator . . . a little >>>> distance really helps. >>>> >>>> Alternatively, an electronic compass with >>>> a remote sensor out in a wing is the best >>>> way to achieve the highest performance >>>> in a magnetic direction indicator. The >>>> case can be made that since you have >>>> 3 sources of DC power, reliability of >>>> the electronic compass is assured. I would >>>> also hope that you carry a hand-held GPS >>>> in the flight bag too. >>>> >>>> I'm not sure I'd bother to install a >>>> whisky compass any more. Likelihood of >>>> ever needing one these days is about nil. >>>> Same thing happened to buggy whips. We >>>> were fortunate not to be plagued by the >>>> FHA (Federal Horsecart Administration) >>>> when the transition occurred. Hmmmm . . . >>>> maybe they didn't really go away . . . >>>> they just morphed into radio antennas. >>>> >>>> Let's be really clear about this condition. >>>> This is NOT a downside checkmark on the blackboard >>>> for the B&C SD-20. ALL alternators have a steel >>>> shaft that runs through the device parallel >>>> to the magnetic lines of force generated in >>>> the field windings. See: >>>> >>>> http://www.aeroelectric.com/Pictures/Alternators/Alternator_w_Inte >>>> rnal_Fan2.gif >>>> >>>> This mechanical feature insures that EVERY >>>> alternator will present a strong external >>>> magnetic field. It's a system integration problem >>>> that seldom presents but has multiple solutions >>>> for maintaining flight-system reliability. The >>>> REAL problem is getting those-who-know-more- >>>> about-airplanes-than-we-do to join us in >>>> the 21st century. >>>> >>>> Bob . . . >>>> >>>> ________________________________ Message 22 ____________________________________ Time: 07:06:03 PM PST US From: "Carl Morgan" Subject: RE: AeroElectric-List: B&C SD-20 and magnetic interference Very interesting - Thanks Kevin.... This could be a short term solution for the paperwork battle.... Carl PS: I wonder how close a C550 is to a glider with both generators OFF ;-) > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of > Kevin Horton > Sent: 26 March 2008 14:17 > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: B&C SD-20 and magnetic interference > > > > > There are type certificated aircraft where the whiskey compass is > only accurate in a very particular electrical system configuration. > For example, on the Cessna C550 (Citation II business jet), the > whiskey compass is only useable if both generators are OFF. This is > quite acceptable to the FAA, Transport Canada, and I presume the NZ CAA. > > Given that you have an EFIS with a remote flux valve that acts as > your primary source of magnetic heading, you don't need the whiskey > compass to read accurately most of the time. I wonder if it might be > acceptable to put a placard by the whiskey compass that said "SD-20 > Alternator must be OFF to use compass". Then make a compass > correction card that is only valid if the SD-20 is OFF. > > Kevin Horton > > > On 25 Mar 2008, at 19:51, Carl Morgan wrote: > > vii@rvproject.gen.nz> > > > > Hi Matt, > > > > Thanks for the ideas, I'm really not that concerned about the whiskey > > compass functionality - if I've lost all my other mag direction > > indicators - > > the engine has stopped, so I don't really care about direction ;-) > > However > > the CAA so far is and the calibration card per regs has to be > > within 10 > > degrees :-(. > > > > SD-20 off / disconnected - yes I think the compass reads right - > > but we are > > dual bus (two independent active buses), not endurance / essential > > bus - so > > both alts need to be running / working. > > > > Wire routing - the B lead and field goes aft from the SD-20 to the > > firewall, > > left across the top of the firewall, aft again through the firewall > > and back > > to a mid location for the regulator which is on a tray between the > > forward > > panel ribs (RV 7A Tipup). > > > > Remote compass - it could yet be the option - but I don't like to > > even think > > about the routing of the cables through the tunnel / spar / wing..... > > > > Regards, > > > > Carl > > -- > > Carl Morgan - ZK-VII - RV 7A > > http://www.rvproject.gen.nz/ > > > >> -----Original Message----- > >> From: owner-aeroelectric-list-server@matronics.com > >> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of > >> Matt > >> Prather > >> Sent: 26 March 2008 11:59 > >> To: aeroelectric-list@matronics.com > >> Subject: RE: AeroElectric-List: B&C SD-20 and magnetic interference > >> > >> > >> > >> > >> Are _you_ concerned about the function of the whiskey compass? If > >> not > >> (given the other equipment on board), do your best to come up with a > >> calibration card for it and call it good. > >> > >> Side question.. I got the impression that your compass reads > >> accurately > >> when the field is turned off on the SD-20. Can the SD-20 be used > >> only > >> when your main alternator is off line? If so, the only time your > >> compass > >> will have a problem is if the main alternator fails. I could live > >> with > >> that.. > >> > >> Also, what's the wire routing of the output and field of the SD-20 > >> (with > >> respect to the compass? Is it possible that the wire routing is > >> contributing to the B-field generated by the SD-20? Is the ground > >> following a different route than the field and output wires? I'm > >> pretty > >> sure Bob's assessment of the cause of your headache was correct, > >> but I > >> wonder if there might be additional factors... > >> > >> In a different direction, you can get a remote compass from Century > >> Instruments: > >> > >> http://www.trade-a-plane.com/dispads/0000769074.pdf > >> > >> Kinda spendy at $500 for the kit.. And, I don't know if it actually > >> satisfies the requirement. > >> > >> > >> Regards, > >> > >> Matt- > >> > >>> > >>> > >>> Hi Bob, > >>> > >>> Removing the 'whiskey compass' could / will result in my aircraft > >>> being > >>> grounded. I have been round the loop with the NZ CAA and the > >> 'need' for a > >>> traditional compass, I already have a GRT EFIS with > >> magnetometer, IFR GPS > >>> and still not enough. At the moment it is going to be an up cliff > >>> paperwork > >>> struggle. > >>> > >>> Removing the SD-20 is a 'better' option from their perspective, > >> but with a > >>> full FADEC I'm not comfortable with just dual battery, single > >> alternator - > >>> and having got to this point where the engine is running great > >>> (or too > >>> well) > >>> removing the SD-20 isn't an option either. Distance changing > >> is going to > >>> be > >>> in the order of 1" difference, unless I mounted it in the baggage > >>> compartment. What options can be used to reduce the magnetic > >> impact - is > >>> it > >>> a luck of the draw with the SD-20 - ie. they all vary abit? We > >>> are only > >>> taking 3-4 amps under normal operations. I understand some > >>> interference > >>> coming out, but what is 'too much'? > >>> > >>> WRT: > >>>> This is NOT a downside checkmark on the blackboard > >>>> for the B&C SD-20. ALL alternators have a steel > >>>> shaft that runs through the device parallel > >>>> to the magnetic lines of force generated in > >>>> the field windings. > >>> > >>> My biggest complaint is there is NO indication or warnings about > >>> this > >>> anywhere in the instruction / website information - I would have > >>> reconsidered the panel layout with this information, as it is I'm > >>> fixed > >>> without major rework and it is affecting my Autopilot backup and > >>> one of > >>> the > >>> few instruments the regulator is specifically interested in.... > >>> > >>> How can I reduce this interference at the source - hopefully a small > >>> reduction will be enough to get calibration within spec. > >>> > >>> Thanks, > >>> > >>> Carl > >>> -- > >>> Carl Morgan - ZK-VII - RV 7A > >>> http://www.rvproject.gen.nz/ > >>> > >>>> -----Original Message----- > >>>> From: owner-aeroelectric-list-server@matronics.com > >>>> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of > >>>> Robert L. Nuckolls, III > >>>> Sent: 26 March 2008 00:12 > >>>> To: aeroelectric-list@matronics.com > >>>> Subject: Re: AeroElectric-List: B&C SD-20 and magnetic interference > >>>> > >>>> > >>>> III" > >>>> > >>>> At 09:44 AM 3/25/2008 +1300, you wrote: > >>>> > >>>>> > >>>>> > >>>>> Hi, > >>>>> > >>>>> We have been running for about 20 hours now chasing different > >>>> problems. One > >>>>> outstanding one is magnetic interference from the SD-20 / LR3 > >>>> combination. > >>>>> We have a TSO'd vertical card compass (and yes it is a southern > >>>> hemisphere > >>>>> model) mounted in the middle of the panel area (center/center). > >>>> We are dual > >>>>> alt / dual bus configuration. > >>>>> > >>>>> When the field wire is connected to the SD-20 (lower connection) > >>>> we get up > >>>>> to 40 degree swing on the compass - it does vary in amount > >>>>> (from 20-40 > >>>>> degrees) based on direction - south seems the worst. Pulling > >> the field > >>>>> breaker causes it swings back about 30 degrees, but the > >>>> regulator / alt are > >>>>> still have an affect. > >>>>> > >>>>> B&C are saying some swing is 'normal' - but 40 degrees - I'm > >>>> struggling! I > >>>>> can't calibrate that much out (best effort so far is +- 15 > >>>>> degrees). > >>>>> > >>>>> I've tried changing the location / orientation of the regulator > >>>>> - no > >>>>> difference. I've tried moving another wet compass around the > >>>>> panel / > >>>>> cockpit - it looks like same problem (although a bit hard to > >>>>> tell). > >>>>> > >>>>> I've tried running some grounded braid around the firewall > >>>> forward side of > >>>>> the field wire - no change. Same symptoms on ground, air, zero > >>>> RPM and full > >>>>> power. There may be a small movement (< 3 degrees) based on > >>>>> current > >>>> draw > >>>>> from SD-20. With SD-20 field disconnected and X-Feed in - no > >> movement. > >>>>> > >>>>> Questions: > >>>>> a) Have others got this / solved this? > >>>>> b) Any suggested methods of screening the SD-20? > >>>>> > >>>>> Thanks, > >>>>> > >>>>> Carl > >>>> > >>>> > >>>> The problem is magnetic, not electrical. > >>>> Had this problem on the Bonanza too. The SD-20 > >>>> (as do most alternators) has a considerable > >>>> leakage of magnetic flux from the rotor winding. > >>>> This isn't a problem for most installations > >>>> where the alternator mounts on the front of > >>>> the engine. > >>>> > >>>> Alternators hung on the rear of the engine > >>>> are much closer to the instrument panel and > >>>> more likely to be an issue with a panel > >>>> mounted compass. > >>>> > >>>> In the Bonanza, we moved the compass off the > >>>> glareshield to a location on higher on the > >>>> windshield. Adding a magnetic shield around > >>>> the SD-20 is a pretty busy task. The shield > >>>> material would have to be magnetic and cover > >>>> the rear and perhaps the circumference of the > >>>> alternator. This has some issues with cooling, > >>>> wiring egress and labor to implement it. > >>>> > >>>> The easiest fix is to increase distance between > >>>> the compass and the alternator. Magnetic > >>>> 'radiation' is a weak propagator . . . a little > >>>> distance really helps. > >>>> > >>>> Alternatively, an electronic compass with > >>>> a remote sensor out in a wing is the best > >>>> way to achieve the highest performance > >>>> in a magnetic direction indicator. The > >>>> case can be made that since you have > >>>> 3 sources of DC power, reliability of > >>>> the electronic compass is assured. I would > >>>> also hope that you carry a hand-held GPS > >>>> in the flight bag too. > >>>> > >>>> I'm not sure I'd bother to install a > >>>> whisky compass any more. Likelihood of > >>>> ever needing one these days is about nil. > >>>> Same thing happened to buggy whips. We > >>>> were fortunate not to be plagued by the > >>>> FHA (Federal Horsecart Administration) > >>>> when the transition occurred. Hmmmm . . . > >>>> maybe they didn't really go away . . . > >>>> they just morphed into radio antennas. > >>>> > >>>> Let's be really clear about this condition. > >>>> This is NOT a downside checkmark on the blackboard > >>>> for the B&C SD-20. ALL alternators have a steel > >>>> shaft that runs through the device parallel > >>>> to the magnetic lines of force generated in > >>>> the field windings. See: > >>>> > >>>> http://www.aeroelectric.com/Pictures/Alternators/Alternator_w_Inte > >>>> rnal_Fan2.gif > >>>> > >>>> This mechanical feature insures that EVERY > >>>> alternator will present a strong external > >>>> magnetic field. It's a system integration problem > >>>> that seldom presents but has multiple solutions > >>>> for maintaining flight-system reliability. The > >>>> REAL problem is getting those-who-know-more- > >>>> about-airplanes-than-we-do to join us in > >>>> the 21st century. > >>>> > >>>> Bob . . . > >>>> > >>>> > > > Checked by AVG. > 25/03/2008 10:26 > Checked by AVG. 10:26 ________________________________ Message 23 ____________________________________ Time: 08:20:40 PM PST US From: "Mike Creek" Subject: RE: AeroElectric-List: Alternator Try Vans web store (www.vansaircraft.com). They have alt brackets for reasonable prices. However, having gone down this road myself, I would recommend going with the PP alternator. I first bought the Vans mounts and later switched to the PP. You'll be really happy with it and their mounting brackets. Mike _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bryan Sent: Tuesday, March 25, 2008 2:26 PM Subject: AeroElectric-List: Alternator I have a 12V 60A Chrysler alternator that came with the engine I am rebuilding. Unfortunately I do not have the brackets for this alternator. Does anyone know where to get brackets for a reasonable price (I don't even know what part number), or would I be better off just going with a Plane Power kit? Thanks Bryan ________________________________ Message 24 ____________________________________ Time: 09:02:22 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: oddball 0.25" fast-on terminal source? At 06:48 PM 3/25/2008 -0500, you wrote: > >D, > I had the same issue and bought a roll of AMP tin plated for 18-22 >AWG wire. >DigiKey P/N A27933CT-ND >AMP P/N 60295-2 >If these will help send me your address off list and I will mail you a few. >I bought 100 and needed 3 :( I just couldn't think of butt splices on the >Alternator wires. Why butt splice? You can do a very compact, robust solder splice. See: http://aeroelectric.com/articles/Tech_Tips/Solder_Lap_Splicing/Solder_Lap_Splices.html 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.