---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 02/12/09: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:47 AM - Re: z-14 ? (Robert L. Nuckolls, III) 2. 05:22 AM - Re: Engine ground on RV 10 (Robert L. Nuckolls, III) 3. 07:52 AM - Pitot Heat (Neal George) 4. 08:10 AM - Re: Pitot Heat (Ralph E. Capen) 5. 08:43 AM - Re: Pitot Heat (Ron Quillin) 6. 08:47 AM - Potential Exp Load Center Failure Mode (Ed Anderson) 7. 10:06 AM - Re: Revision 12 Z Figures (Jeff Page) 8. 12:26 PM - Re: Engine ground on RV 10 (rparigor@SUFFOLK.LIB.NY.US) 9. 02:26 PM - Two speed trim contoller (Stan Blanton) 10. 03:04 PM - Re: Two speed trim contoller (Bob-tcw) 11. 03:11 PM - Re: Engine ground on RV 10 (Robert L. Nuckolls, III) 12. 03:37 PM - Re: Engine ground on RV 10 redux (Robert L. Nuckolls, III) 13. 05:03 PM - Re: Engine ground on RV 10 (Bill Mauledriver Watson) 14. 07:56 PM - Re: Engine ground on RV 10 (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 04:47:12 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: z-14 ? At 06:13 PM 2/11/2009, you wrote: > >Bob thanks for the Z-33 that shows duel power to contactors. This >has lead to another question. I have S701-1 type contactors as shown >in Z-14. My contactors only have one small stud that closes the >contactor when grounded Can these be wired for duel power sources >or do I need to replace them with S701-2 type contactors. . Thanks Tim The only difference between a 701-1 and 701-2 is how the diodes are installed. You can remove the jumper wire on a -1 and add two diodes to convert it to a -2. The only time you would need to replace the contactor is if you had purchased a 3-terminal device common to other suppliers of battery contactors. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 2 _____________________________________ Time: 05:22:15 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Engine ground on RV 10 At 02:06 PM 2/11/2009, you wrote: > >Bob Nuckolls, > >You said below that stainless firewall sheet is not a GOOD conductor. >Will you please quantify that statement? How much worse is it than >2024-T3 aluminum? > >I have a battery in the tail of my airplane that is grounded through the >airframe, but the forest of ground tabs is on the stainless steel >firewall. Does that mean that I need to run a fat wire from the forest >of tabs attach bolt on the stainless steel firewall to some portion of >the aluminum airframe? It wouldn't hurt. The simple answer to your question is that stainless steels are between 10 and 30% as good a conductor of electron flow as annealed copper. That sounds worse than it is in this case because we're not dealing with a long, thin conductor between point A (your battery ground) and point B (your forest-of-tabs). Imagine if you will 1,000,000 conductors between A and B. Each conductor is made of aluminum (A-to edge of firewall) where a piece of stainless wire is spliced on (edge of firewall to B). While the addition of the stainless might make the over all path resistance of any one conductor jump by a factor of 3 to perhaps even 10x, the PARALLELED value of all those conductors is still a rather low number. As an example, I think I heard a number offered in a meeting on lightning issues that the resistance of a Model 400 Beechjet from nose to tail was on the order of 1 milliohm. Pretty low as far as cranking engines was concerned (assuming that you ran cranking current the length of the airplane!). In terms of 100,000 amp lightning strikes, that 1 milliohm was quite significant for other concerns. If you visualize your point A to point B conduction pathway as a wire frame made up of many paralleled paths of connected airframe components, the whole thing is still pretty good (with "pretty" being "terribly" non-quantified . . . terribly isn't well quantified either). The point is that while the stainless steel as a single entity in a huge array of entities doesn't cause the cranking current pathway to become useless. The concerns come with ageing of the airframe where new rivets that were swelled up in tight holes become less conductive with time in service and environmental effects. It would be interesting to get a conductivity measurement between the center of the firewall sheet and the battery (-) terminal of your airplane before and after adding a fat-wire jumper. I did have occasion to measure the battery(-) to crankcase resistance on a wrecked 172. See http://www.aeroelectric.com/articles/grnding.pdf Even in the bent state, the resistance was just under 3 milliohms. Know too that the majority of that resistance came from wire and joints in wires use to complete the chain. The airframe would have been a small fraction of the total. If this sounds like an indefinite answer as to the value of adding the jumper wire, you're right. Your brand new airplane as-assembled will probably not show the effects of less-than-the-best grounding. But as a matter of experience and good practice let me offer that I try to avoid using the firewall sheet (indeed other parts of the airframe) as the universal ground conductor. This is discussed in the 'Connection and in Figure Z-15. Adding the jumper now and then using the airframe for grounding ONLY a few remote accessories is a good thing to do for the owner-operator that's going to be flying this airplane 20 years from now . . . hopefully that's you. Bob . . . ________________________________ Message 3 _____________________________________ Time: 07:52:02 AM PST US From: "Neal George" Subject: AeroElectric-List: Pitot Heat Bob - I have an AN5814-1 heated pitot-static tube. This monster draws over 20-amps at turn-on, and settles down around 12-amps or so. How would you recommend I feed it? Fat breaker on the panel? S704-1 relay? Something else? neal ________________________________ Message 4 _____________________________________ Time: 08:10:48 AM PST US From: "Ralph E. Capen" Subject: Re: AeroElectric-List: Pitot Heat I have a fuse on mine - 30 I think....looks like you're considering the switch too based on your possible use of a relay. Ralph RV6A N822AR @ N06 3.7 hrs.... -----Original Message----- >From: Neal George >Sent: Feb 12, 2009 10:49 AM >To: aeroelectric-list@matronics.com >Subject: AeroElectric-List: Pitot Heat > > >Bob - > >I have an AN5814-1 heated pitot-static tube. This monster draws over >20-amps at turn-on, and settles down around 12-amps or so. How would you >recommend I feed it? > >Fat breaker on the panel? >S704-1 relay? >Something else? > >neal > > ________________________________ Message 5 _____________________________________ Time: 08:43:28 AM PST US From: "Ron Quillin Subject: Re: AeroElectric-List: Pitot Heat At 07:49 2/12/2009, you wrote: >I have an AN5814-1 heated pitot-static tube. This monster draws over >20-amps at turn-on, and settles down around 12-amps or so. How would you >recommend I feed it? Just as a point of reference, we have the same PS tube in a certified AC. It's fed through a 20A breaker and a Carling rocker switch with faston tabs. No problems so far. It will be 36 years this August. Ron Q. ________________________________ Message 6 _____________________________________ Time: 08:47:14 AM PST US From: "Ed Anderson" Subject: AeroElectric-List: Potential Exp Load Center Failure Mode A potential Damage mode of the EXP2 Load Center. PROBLEM Recently a couple of friends of mine flew an RV that had been purchased, from Texas back to NC. The RV had been checked by an RV "broker" and seemed to be Ok short of having a dead battery. The battery was replaced and the next morning and my two friends launched into what was to become a nerve racking flight. Getting up the next morning to start their return trip, they discovered that the new battery was dead and would not crank the aircraft. The alternator was functioning OK and reducing electrical load to the minimum they decided to continue the trip (with jump starts at every stop) until arriving safely. Having a bit of experience with electrical systems, I was asked to take a look at the problem. The aircraft had an EXP2, a load center with toggle switches installed. I was not familiar with the unit, but after getting the schematic for the wiring of the EXP2 board, the first thing I notice was that the Master relay on the board was missing and the socket holes taped over with masking tape - which I though rather odd. Reading the specifications, I discovered the relay could be replaced with a special jumper (as explained later - it has to be this special jumper - a plain wire jumper will not work) in event an external master contactor was used, but the manufacture's jumper was not present either. I found that even with the relay missing and no jumper present in the relay socket and the Master Switch OFF that there was still continuity between the alternator and battery terminals on the EXP2 board - again, I though that rather odd. More on why this continuity later. CURRENT OVERLOAD To make a long story short, upon further examination, it was apparent that the EXP2 board had encountered a heavy current overload at some point. This overload apparently not only fried the on-board relay but did cause the copper leads on the EXP2 board to become hot enough for the solder coating to melt and run off of some of the copper leads. When the board was removed it became clear that someone had solder a heavy strip on the underside of the board to complete a circuit between alternator and battery across the relay socket terminals - apparently in attempt to jump the damaged relay position. INEFFECTIVE REPARE ATTEMPT However, that specific attempt at repair kept the battery terminal on the EXP2 board connected to EXP2 board Alternator terminal at all times - even when the master switch was OFF. With a functioning on-board relay present, the circuit between battery and alternator terminals on the EXP2 is broken when the master switch is off. But, the jumper repair soldered across the relay position maintained the contact between alternator and battery terminals regardless of master switch position. This electrical system had one external master solenoid. When this solenoid is closed the battery circuit is completed to both the starter and to the Exp2 Battery Terminal. IF the on-board relay (or manufacture's jumper) is installed and the master switch is ON then the EXP2 on-board battery terminal is also connected with the alternator terminal through the EXP2 board. If the external solenoid is open then only a no. 18 AGW wire connects the hot side of the solenoid to the master switch on the board. When this master switch is ON it grounds the external solenoid relay circuit causing the external solenoid to close the high current path and connect the battery to the rest of the system (including the alternator). Turning the Master switch ON also clauses the on-board relay to close which is what actually interconnects the battery and alternator terminals on the board. EFFECT OF REPARE ATTEMPT There appears to be two potential drain paths resulting from the makeshift jumper across the on-board relay position. Shown in the broken red line on the attached schematic, there was a low current (no. 18 wire) hot lead off the battery side of the ext. solenoid to the Master Switch. When the Master switch was turned on (grounded) - it completed the circuit to ground and permitted current to flow through the solenoid coil closing the external solenoid which then provided the high current direct path between battery and alternator for heavy current flow. However, even when the Master Switch was OFF (ungrounded) and the external solenoid open it appears there was still a steady drain through this line to board and hence the alternator (and any keep alive load fed from the board). This of course produced a continuous battery drain with the engine off and master off. This current drain (through the load resistance of the alternator and board) after engine shut down may have been low enough to preclude activating the external solenoid in which case it would take longer to drain the battery. However if this drain (with the master off and ungrounded) was sufficient, it may have kept the external solenoid close long enough to drain most of the battery, before battery power fell too low for the flow to keep the relay close in which case, it would open - but, drain would still continue through the low current path shown by the dashed red through the master switch circuit. Resulting in a dead battery. I still have one puzzle- if the alternator and battery are always connected on the board, I could see the drain over night, but why wouldn't the battery get charged during flight - surely enough to turn the engine over at the next stop? Well, I have a hypothesis I've posted at the end of this e mail for you electrical types. I'd be interested in feed back on it - or your viewpoint as to why the battery would not charge in flight. Thanks in advance. After tracing the rest of the aircraft electrical power system and finding out it was wired according to the recommendations in the EXP2 manual, a new EXP2 board was installed and everything functioned normally. Note. I could not find any alternator fuse link - it may have been present, but no extended search was made for it as it was clear there was continuity to the alternator. POSSIBLE CAUSE In trying to figure out what had happened to cause the power surge and looking at the EXP2 diagram, one possible scenario became clear. IF someone left the master switch ON and then while replacing or messing around with alternator, permitted the alternator "B" lead to become grounded, a circuit (short) is completed from battery to ground with the EXP2 on-board relay in between. The very high battery current flow would be from the battery through the EXP2 board's relay and circuit board leads to the grounded "B" lead. Certainly higher than the 40 amps rating of the on board relay and apparently enough current to heat some of the copper leads on the EXP2 board above the melting point of their solder coating. It was equally clear that had the master switch been OFF which would have had the on-board relay open (and no connection between battery and alternator) that the grounding of the "B" lead would have been a non-event. Naturally, I do not know for certain if this was what actually happened, but it is clear that it easily could. It is possible that if the repair jumper were removed and a new relay installed that the old EXP2 board would have functioned properly, but given the metal solder that flowed from the copper traces, I personally felt the only prudent thing to do was to replace the entire board. The new owner agreed and that is what was done. Who knows that effect that overstress condition might have had on other components or the board itself. I have no dogs in this fight and simply want to pass on to others using the EXP2 about this possible failure mode - which may not necessarily be unique to the EXP2. Given the nature and magnitude of the current Overload - one could conclude that the EXP2 design is rather robust and damage tolerant. A fuseable link between alternator and board may have helped - if it were not rated at much more than 40 amps, otherwise a higher rated fuse link would have still resulted in current flow exceeding the stated rating of the on-board relay of 40 amps. My analysis may be incorrect - but the damage was very real. Naturally, detaching the battery is always the safest approach but not always followed, but at least with the EXP2 make certain the Master switch if OFF before messing with your alternator. There may be other scenarios that could have caused this problem but that seem to be most probable. Best Regards Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW Addendum Hypothesis: Given the apparent connections with the attempted jumper repair, I would have expected that the alternator would at least keep the battery charged sufficiently to restart the engine after a short refueling stop. However, this was not what the pilots ferring the plane back experienced. They hand propped after one stop and got jump starts at the remaining stops. But, still it would have seemed that with the alternator charging that the battery would have been charged sufficient for a start after a short stop even if it would be expected to drain down overnight. The only scenario I could come up with that might explain why the battery never seems to receive a charge from the alternator follows: Hypothesis. The external selonoid control all access to the battery with the exception of one wire from the hot side of the selonoid which went to the EXP2 board master switch. When the master switch was turned on (grounded) this permitted current flow through the relay coil of the external solnoid and close the high current path between battery and starter and the rest of the electrical system including the alternator. In other words, if this relay were open then there was no connection between alternator and battery, if close then connection existed. My though goes along these lines ( and I would like any input as to view as to the plausability of this being correct or incorrect). IF only the current flowling though the external solenoid maintained it closed and permitted continunity with the altnerator throught the EXP2 board then anything that resulted in decreased current flow could cause that relay to open. It appears that the current through the master switch is limited to that flowing through the relay coil of the external solenoid provide by the battery potential. It would appear that if through this repair jumper the alternator voltage appeared on the master switch circuit that it would tend to neutrailze or at least reduce the current flow. IF it did reduce it below the hold down current required then the external solnoid would open removing the battery from the electrical system including the alternator while the engine was running. While the engine is off or during starting - the alternator is not putting out voltage therefore the battery potential holds the external selnoid closed with the master switch closed. However, once the engine starts running the altenrator potential comes on line and exceeds that of the partially drained battery. IF the attempted repair resulted in the alternator voltage appearing on that circuit and neutralizing the battery poential to move current through the relay, its seems possible that the external selnoid could open and remain open during alternator operation preventing charging of the battery. IF correct then you would have the worst of both worlds, the battery being heavily drained by the starting current load and not being able to get any recharge from the alternator and then would be drained down overnight I admit, a wild stab in the dark, but the only one I could come up with. ________________________________ Message 7 _____________________________________ Time: 10:06:23 AM PST US From: "Jeff Page" Subject: AeroElectric-List: Re: Revision 12 Z Figures Some possible updates to Z figures: Z15K3p2 2nd paragraph, second line, change "Busses at" to "Busses are" 3rd paragraph, 5th line, "crancase" to "crankcase" 3rd paragraph, 6th line, "leas" to "least" 4th paragraph, 1st line, ""bee" to "been" Z17 On diagram, label Dynamo as B&C SD-8 and regulator as B&C PMRIC-14 Z25 - Self-excitation components missing. possibly show the SD-8 wires twisted ? If you are intentionally deleting the self-excitation feature, delete references to it in Z10-8A2 and Note 25. If you want to promote the self-excitation feature, add reference to it in Z16, Z17 Note 4 - Perhaps update the discussion here. When I read this the first time, my impression was that I could choose a fuselink by selecting 4AWG smaller than the wire to be protected. Discussions with you on this list indicated that this was an over-simplification and that I should only use fuselinks as shown in the Z diagrams. Perhaps additional discussion here to explain some details, or some caution that additional learning is required to select fuselink sizes. Note 25. I have 1K, Z21A shows 3K resistor for SD-8 self-excitation. Wish List: I am particularly fond of Z13/8. As a step up, using Emagair ignitions and an SD-8 aux alternator, I would suspect many builders would also opt for B&C's LR3C-14 regulator instead of the generic Ford regulator. Perhaps draw it that way ? With two electrically dependent ignitions, it seems to me the holy grail of architectures would be completely isolated electrical systems as the only true guarantee of no single fault causing disaster. Z14 is much more than needed to accomplish this goal. A major revision to Z13/8 would add a small battery to go with the SD-8, feeding the second ignition from an independent battery bus. In the event of a main alternator failure, a cross-feed relay would allow the SD-8 to feed the endurance bus. The aux battery would not be used to feed the starter motor. If you believe this a worthy design goal, perhaps add a drawing to illustrate it ? Jeff Page Dream Aircraft Tundra #10 ________________________________ Message 8 _____________________________________ Time: 12:26:43 PM PST US Subject: RE: AeroElectric-List: Engine ground on RV 10 From: rparigor@SUFFOLK.LIB.NY.US Hi Bob "The simple answer to your question is that stainless steels are > between 10 and 30% as good a conductor of electron flow as > annealed copper. " Did you add a decimal place stating between 10 and 30% and mean 1 and 3%?? According to this table: http://www.ndt-ed.org/GeneralResources/MaterialProperties/ET/ET_matlprop_Iron-Based.htm between 1 + 3% is more accurate?? Ron Parigoris Just as a reference annealed copper is 100% and silver 106%: http://www.wisetool.com/designation/cond.htm ________________________________ Message 9 _____________________________________ Time: 02:26:07 PM PST US From: "Stan Blanton" Subject: AeroElectric-List: Two speed trim contoller Bob, Some time ago you published a schematic for a two speed trim controller. Has that project ever been completed or should I try to fab one on my own? The same question in regard to a basic mod of your dimmers to allow them to be used in a similar fashion to control trim servo speedd. Thanks, Stan Blanton RV-6 Extreme Slow Build ________________________________ Message 10 ____________________________________ Time: 03:04:02 PM PST US From: "Bob-tcw" Subject: Re: AeroElectric-List: Two speed trim contoller Stan, If you are interested in a pre-made product which includes two speed trim control along with run-away trim prevention you may want to visit. www.tcwtech.com Thanks, Bob Newman TCW Technologies ----- Original Message ----- From: "Stan Blanton" Sent: Thursday, February 12, 2009 5:22 PM Subject: AeroElectric-List: Two speed trim contoller > > > Bob, > > Some time ago you published a schematic for a two speed trim controller. > Has that project ever been completed or should I try to fab one on my own? > > The same question in regard to a basic mod of your dimmers to allow them > to > be used in a similar fashion to control trim servo speedd. > > Thanks, > > Stan Blanton > RV-6 > Extreme Slow Build > > > ________________________________ Message 11 ____________________________________ Time: 03:11:13 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Engine ground on RV 10 At 02:23 PM 2/12/2009, you wrote: >Hi Bob > >"The simple answer to your question is that stainless steels are > > between 10 and 30% as good a conductor of electron flow as > > annealed copper. " > >Did you add a decimal place stating between 10 and 30% and mean 1 and 3%?? > >According to this table: > >http://www.ndt-ed.org/GeneralResources/MaterialProperties/ET/ET_matlprop_Iron-Based.htm > >between 1 + 3% is more accurate?? Good eye! I tried to do conductance values to percentages of resistance . . . Thanks! Bob . . . ________________________________ Message 12 ____________________________________ Time: 03:37:48 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Engine ground on RV 10 redux >At 02:23 PM 2/12/2009, you wrote: >>Hi Bob >> >>"The simple answer to your question is that stainless steels are >> > between 10 and 30% as good a conductor of electron flow as >> > annealed copper. " >> >>Did you add a decimal place stating between 10 and 30% and mean 1 and 3%?? >> >>According to this table: >> >>http://www.ndt-ed.org/GeneralResources/MaterialProperties/ET/ET_matlprop_Iron-Based.htm >> >> >>between 1 + 3% is more accurate?? > > > Good eye! I tried to do conductance values to > percentages of resistance in my head . . . Thanks! > > Bob . . . ________________________________ Message 13 ____________________________________ Time: 05:03:31 PM PST US From: Bill Mauledriver Watson Subject: Re: AeroElectric-List: Engine ground on RV 10 Robert L. Nuckolls, III wrote: > That's ONE braided jumper strap (or 2AWG welding cable > with terminals and heat-shrink) and as many thin, flat, sheet > metal bonding straps as you have shock mounts (usually > 4). Bob, I want to do that on my RV10. I have the forest of tabs on the firewall which has an 8AWG wire running back to the battery. I'll run a braided jumper strap from the bolt on the forest of tabs to wherever it's best connect it to the IO540 crankcase. And I understand it doesen't really ground the engine as much as it grounds the forest of tabs. But what do the 4 "thin flat sheet metal bonding straps" look like? I'm imagining something forming an arc around the non-conductive shock mounts but I've never seen this and can't find a reference. Can you elaborate a bit here or point me to the photos you probably have out on your site? Is this something I fabricate or buy? If anyone can help me identify the ground lug on the RV10 engine mount or the best place to attach a ground on the crankcase, I'd appreciate it. Thanks. Bill "ready to hang the engine" Watson ________________________________ Message 14 ____________________________________ Time: 07:56:19 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Engine ground on RV 10 At 06:59 PM 2/12/2009, you wrote: > > >Robert L. Nuckolls, III wrote: >> That's ONE braided jumper strap (or 2AWG welding cable >> with terminals and heat-shrink) and as many thin, flat, sheet >> metal bonding straps as you have shock mounts (usually >> 4). >Bob, I want to do that on my RV10. I have the forest of tabs on the >firewall which has an 8AWG wire running back to the battery. Eliminate this dude. It's contribution is too tiny to measure much less observe. Ground battery through 4AWG welding cable to the same class of structure as cited below . . . > I'll run a braided jumper strap from the bolt on the forest of > tabs to wherever it's best connect it to the IO540 crankcase. And > I understand it doesen't really ground the engine as much as it > grounds the forest of tabs. Okay, add another fat-wire jumper from forest of tabs to structure right behind the firewall. Anyone out there got a picture of the heavy metal under the floorboards between the rudder pedals? >But what do the 4 "thin flat sheet metal bonding straps" look >like? I'm imagining something forming an arc around the >non-conductive shock mounts but I've never seen this and can't find >a reference. Can you elaborate a bit here or point me to the photos >you probably have out on your site? Is this something I fabricate or buy? Leave those off. We distilled this process down a bit from the first thought about using the shock-mount straps. It's STILL a good idea not to use the engine mount for anything other than holding the engine on the airplane. >If anyone can help me identify the ground lug on the RV10 engine >mount or the best place to attach a ground on the crankcase, I'd appreciate it. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ------------------------------------------------------------------------------------- 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.