---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 08/16/03: 19 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:12 AM - Two Voltage Inputs on JPI EDM900 (MikeEasley@aol.com) 2. 05:22 AM - Re: Battery Cable (Charlie Kuss) 3. 06:48 AM - Re: Battery Cable (Eric M. Jones) 4. 10:20 AM - Re: Analog to digital converter (David.vonLinsowe) 5. 11:21 AM - Re: Re: Battery Cable (Robert L. Nuckolls, III) 6. 11:23 AM - Re: Battery (Welding) cable (Treff, Arthur) 7. 12:38 PM - Battery Cable (Eric M. Jones) 8. 01:22 PM - Re: Battery voltage on start (Robert L. Nuckolls, III) 9. 02:05 PM - Re: Analog to digital converter (Jim Jewell) 10. 02:38 PM - Re: EFIS (Robert L. Nuckolls, III) 11. 02:48 PM - Re: New FAA AC On Amateur Built Aircraft (glong2) 12. 05:28 PM - Relying on non-certified EFIS in IFR (Dan O'Brien) 13. 08:03 PM - Re: Analog to digital converter (Dave von Linsowe) 14. 08:12 PM - Re: New FAA AC On Amateur Built Aircraft (Dave von Linsowe) 15. 08:17 PM - (no subject) (Speedy11@aol.com) 16. 08:42 PM - Re: New FAA AC On Amateur Built Aircraft (William) 17. 09:40 PM - Re: Battery voltage on start (Dave Grosvenor) 18. 10:24 PM - soldering iron wattage (drew.schumann@us.army.mil) 19. 11:41 PM - Re: soldering iron wattage (Jim Jewell) ________________________________ Message 1 _____________________________________ Time: 05:12:09 AM PST US From: MikeEasley@aol.com Subject: AeroElectric-List: Two Voltage Inputs on JPI EDM900 --> AeroElectric-List message posted by: MikeEasley@aol.com Robert, JPI just told me that the next software update for the EDM900 will allow for a second voltage input so you can monitor both busses. Ask and you shall receive! Mike Easley Lancair ES Colorado Springs ________________________________ Message 2 _____________________________________ Time: 05:22:07 AM PST US From: Charlie Kuss Subject: Re: AeroElectric-List: Battery Cable --> AeroElectric-List message posted by: Charlie Kuss Hi Eric, I am interested in this product. Could you give us some more info? What type of insulation does this wire have? What is the outside diameter of the 0/1 wire? What are the "specs" on the wire's insulation? What type of terminals are recommended? Is the wire "tinned"? Charlie Kuss RV-8A cockpit systems stuff >--> AeroElectric-List message posted by: "Eric M. Jones" > >I still intend to sell Copper Clad Aluminum but I have seen little interest. I would hate to get stuck with the mile of this that I have to buy. Anyone interested? Details on my website. > >Regards, >Eric M. Jones >www.PerihelionDesign.com >113 Brentwood Drive >Southbridge MA 01550-2705 >Phone (508) 764-2072 >Email: emjones@charter.net > >"I'm not going to buy my kids an encyclopedia. Let them walk to school like I did." > --Yogi Berra > > ________________________________ Message 3 _____________________________________ Time: 06:48:10 AM PST US From: "Eric M. Jones" Subject: AeroElectric-List: Re: Battery Cable --> AeroElectric-List message posted by: "Eric M. Jones" >Hi Eric, >I am interested in this product. Could you give us some more info? What type of >insulation does this wire have? What is the outside diameter of the 0/1 wire? >What are the "specs" on the wire's insulation? What type of terminals are recommended? >Is the wire "tinned"? >Charlie Kuss >RV-8A cockpit systems stuff Copper-clad aluminum differs from ordinary wire in that the copper is not plated on, but consists of a fused-on layer that is 10% of the diameter of the aluminum. So you can solder the wire or use other standard techniques. The wire is not tinned, but this could be added to the spec. Should it be? Right now the cable is only a pending order for raw material on my "to-do" list. So next week I'll crank this adventure up and start the process. Soon there will a half-ton spool of cable where my wife parks her minivan. The 1/0 cable is 0.500" diameter including insulation. The insulation at this time is not specified but we want: good cut resistance, low flammability, low smoke generation, moderate flex, moderate cost. Your suggestions are welcome. More information on my website. http://www.periheliondesign.com/fatwires.htm Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 Phone (508) 764-2072 Email: emjones@charter.net "I only regret my economies." --Reynolds Price ________________________________ Message 4 _____________________________________ Time: 10:20:09 AM PST US Subject: Re: AeroElectric-List: Analog to digital converter From: "David.vonLinsowe" --> AeroElectric-List message posted by: "David.vonLinsowe" VGltZTogMDY6MTY6NTEgUE0gUFNUIFVTDQpGcm9tOiAiUm9iZXJ0IEwuIE51Y2tvbGxzLCBJSUki IDxib2IubnVja29sbHNAY294Lm5ldD4NClN1YmplY3Q6IFJlOiBBZXJvRWxlY3RyaWMtTGlzdDog QW5hbG9nIHRvIGRpZ2l0YWwgY29udmVydGVyDQoNCi0tPiBBZXJvRWxlY3RyaWMtTGlzdCBtZXNz YWdlIHBvc3RlZCBieTogIlJvYmVydCBMLiBOdWNrb2xscywgSUlJIiBib2IubnVja29sbHNAY294 Lm5ldA0KDQoNCiAgID4+PiBTaG9ydCBhbnN3ZXIgaXMgdGhhdCB0aGUgaGFyZHdhcmUgaXMgZWFz eSBhbmQgY2hlYXAuDQogICAgVGVsbGluZyB0aGUgaGFyZHdhcmUgaG93IHRvIGRvIGl0J3Mgam9i IGlzIHRoZSBjaGFsbGVuZ2luZw0KICAgIHBhcnQgYW5kIHdvdWxkIHByb2JhYmx5IG5lZWQgc29t ZSBjb29wZXJhdGlvbiBvbiB0aGUgcGFydCBvZg0KICAgIE1yLiBZb3Vua2luLg0KDQogICAgQm9i IC4gLiAuDQoNClRoYW5rIHlvdSBCb2IuDQoNCkRhdmUNCg0KRG8gbm90IGFyY2hpdmUNCg0KDQoN Cg== ________________________________ Message 5 _____________________________________ Time: 11:21:12 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Battery Cable --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:51 AM 8/16/2003 -0400, you wrote: >--> AeroElectric-List message posted by: "Eric M. Jones" > > >Hi Eric, > >I am interested in this product. Could you give us some more info? What >type of > >insulation does this wire have? What is the outside diameter of the 0/1 >wire? > >What are the "specs" on the wire's insulation? What type of terminals are >recommended? > >Is the wire "tinned"? > >Charlie Kuss > >RV-8A cockpit systems stuff > >Copper-clad aluminum differs from ordinary wire in that the copper is not >plated on, but consists of a fused-on layer that is 10% of the diameter of >the aluminum. So you can solder the wire or use other standard techniques. > >The wire is not tinned, but this could be added to the spec. Should it be? If we can live with bare strands in welding cable, I suspect the choice would be no less attractive in copper-clad aluminum . . . by what percentage would "tinning" add to cost? Bob . . . -------------------------------------------- ( Knowing about a thing is different than ) ( understanding it. One can know a lot ) ( and still understand nothing. ) ( C.F. Kettering ) -------------------------------------------- ________________________________ Message 6 _____________________________________ Time: 11:23:00 AM PST US Subject: AeroElectric-List: RE: Battery (Welding) cable From: "Treff, Arthur" --> AeroElectric-List message posted by: "Treff, Arthur" Thanks gang for saving me from my "anal retentive, obsessive-compulsive neurotic self". I will think no more about the battery cables. They are well installed, comfy and cozy. If I had you guys around for the countless other things I re-did due to this disease, I'd be flying by now. Thanks again for all your help! Arthur Treff ________________________________ Message 7 _____________________________________ Time: 12:38:42 PM PST US From: "Eric M. Jones" Subject: AeroElectric-List: Battery Cable --> AeroElectric-List message posted by: "Eric M. Jones" Don't know the cost adder will be for tinning or plating. I will let you know. The insulation will be yellow Radox FX. Really super stuff. Later, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 Phone (508) 764-2072 Email: emjones@charter.net Eric M. Jones When trouble arises and things look bad, there is always one individual who perceives a solution and is willing to take command. Very often, that individual is crazy. --Dave Barry ________________________________ Message 8 _____________________________________ Time: 01:22:17 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Battery voltage on start --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:46 AM 8/16/2003 +0200, you wrote: >--> AeroElectric-List message posted by: "Dave Grosvenor" > >Assuming you have a good battery, how much can you expect the battery >voltage to drop when you hit the starter (50 - 60Amps) for a few seconds? Depends on the battery. There is enough ENERGY in a string of d-size flashlight batteries to crank your engine. Problem is that these small cell are limited in the RATE at which energy can be delivered by a quality known as internal resistance or internal impedance. Further, their small size suggests a limited CAPACITY too . . . meaning that even if these cells would deliver useful output at 60A, your engine would need to start in a few revolutions. We bench test new 17 a.h. RG batteries with enough load to drop the terminal voltage to 8.5 volts. A really robust product will put out 600 amps. A 4-volt drop divided by 600 Amps yields a measured internal impedance on the order of 7 milliohms. Your Your hypothetical for 60A would yield 1/10 the voltage drop on the same battery so it might be expected to stay above 12 volts! As battery characteristics degrade with service or manufacturing techniques, you can EXPECT internal impedance to be higher. A really tired 17 a.h. RG battery will show an internal impedance of 20 milliohms (200A draw) and be pretty close to useless at this condition for larger engines. If you can get going with 60A of cranking current, the "tired" battery will still show a terminal voltage of 11.3 volts . . . Bigger batteries tend to have lower impedances. Products with less-than-the-best construction will have higher impedances . . . but for the purposes of discussing your question, about any RG battery from 10-32 a.h. range should start your engine with ease . . . Most aircraft engines crank in the 150-250A range and can be expected to show what the battery is made of. Your cranking requirements are so much lighter that you can expect to get good cranking performance from some relatively small and/or tired batteries. Bob . . . Bob . . . -------------------------------------------- ( Knowing about a thing is different than ) ( understanding it. One can know a lot ) ( and still understand nothing. ) ( C.F. Kettering ) -------------------------------------------- ________________________________ Message 9 _____________________________________ Time: 02:05:43 PM PST US From: "Jim Jewell" Subject: Re: AeroElectric-List: Analog to digital converter --> AeroElectric-List message posted by: "Jim Jewell" FKJKH)(&*%#&_+_(_&*+_ ......SO THERE! do not archive ----- Original Message ----- From: "David.vonLinsowe" Subject: Re: AeroElectric-List: Analog to digital converter > --> AeroElectric-List message posted by: "David.vonLinsowe" > > VGltZTogMDY6MTY6NTEgUE0gUFNUIFVTDQpGcm9tOiAiUm9iZXJ0IEwuIE51Y2tvbGxzLCBJSUki > IDxib2IubnVja29sbHNAY294Lm5ldD4NClN1YmplY3Q6IFJlOiBBZXJvRWxlY3RyaWMtTGlzdDog > QW5hbG9nIHRvIGRpZ2l0YWwgY29udmVydGVyDQoNCi0tPiBBZXJvRWxlY3RyaWMtTGlzdCBtZXNz > YWdlIHBvc3RlZCBieTogIlJvYmVydCBMLiBOdWNrb2xscywgSUlJIiBib2IubnVja29sbHNAY294 > Lm5ldA0KDQoNCiAgID4+PiBTaG9ydCBhbnN3ZXIgaXMgdGhhdCB0aGUgaGFyZHdhcmUgaXMgZWFz > eSBhbmQgY2hlYXAuDQogICAgVGVsbGluZyB0aGUgaGFyZHdhcmUgaG93IHRvIGRvIGl0J3Mgam9i > IGlzIHRoZSBjaGFsbGVuZ2luZw0KICAgIHBhcnQgYW5kIHdvdWxkIHByb2JhYmx5IG5lZWQgc29t > ZSBjb29wZXJhdGlvbiBvbiB0aGUgcGFydCBvZg0KICAgIE1yLiBZb3Vua2luLg0KDQogICAgQm9i > IC4gLiAuDQoNClRoYW5rIHlvdSBCb2IuDQoNCkRhdmUNCg0KRG8gbm90IGFyY2hpdmUNCg0KDQoN > Cg== > > ________________________________ Message 10 ____________________________________ Time: 02:38:40 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: EFIS --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > >Did you ever consider just adding a good reliable Turn And Bank? That > > would > > >only take up one three and an eighth hole. > > > > and can be as small as 2-1/4" . . . >Good Evening Bob, > >That's true, but my experience with the two and a quarter size has been poor. > I've had three of them fail in less than two thousand hours. I agree two >thousand hours is lot of time, but I have had full size units last for the >life >of an airplane. > >I am sure no expert on instruments, but my local guru tells me that the new >small instruments currently available just are not very good. The ones made >for the military sell for upwards of five grand. Too rich for me. I have >gone >back to using new production three and one-eighth inch T&Bs. Good data point. I think we use 2-1/4" rate indicators on the Beechjet. I'll see if I can probe the service record on these. In any case, 2,000 hours is about 40 years in the life of the average privately owned SE aircraft. If the focus of our concerns is likelihood that a rate instrument will be available to cover the bases for other flight instruments in any single 4-hour flight, even an MTBF of 1,000 hours would give us a pretty good confidence level. If you've got a tandem cockpit aircraft, panel real estate carries a premium price. Bob . . . ________________________________ Message 11 ____________________________________ Time: 02:48:40 PM PST US From: "glong2" Subject: RE: AeroElectric-List: New FAA AC On Amateur Built Aircraft --> AeroElectric-List message posted by: "glong2" QC: I have the same problem. I finally went to the kit supplier (Lancair) and they filled out the proper form (AC 8050-3) that I hope meets the FAA requirement! As I read the original requirement it did not require the form but said it "could be used". When I applied for the registration the FAA came back and said the original bill of sale was not good enough! Eugene Long Lancair Super ES glong2@netzero.net -----Original Message----- **PS: Case in point. I am still in the middle of trying to sort this out, but it appears that the legal types at the FAA aircraft registration office in Oklahoma have decided that a "Bill of Sale" for a kit purchased six years ago is no longer adequate for registration purposes of the aircraft built from that kit even though the present AC 20-27E specifically says "kit Bill of Sale" is what is needed by them. AC 20-27E also says that AC Form 8050-2 Aircraft Bill of Sale MAY be used so now they have upped the ante to say that AC Form 8050-2 MUST be used. Their reasoning is that normal Bills of Sale for kits do not contain the sacred "words of transfer" that are used in the sale / transfer of unique legal entities that have titles such as real estate, automobiles, and aircraft. To my knowledge a collection of material called a kit, that may or may not ever become an aircraft of some form, is not a uniquely identifiable legal entity at the time it passes from the kit providers hands to the amateur builder. So "words of transfer" are not applicable nor required. ________________________________ Message 12 ____________________________________ Time: 05:28:14 PM PST US From: "Dan O'Brien" Subject: AeroElectric-List: Relying on non-certified EFIS in IFR --> AeroElectric-List message posted by: "Dan O'Brien" Reading the thread on the merits/cautions of the newer non-certified EFIS systems prompts me to describe my own plans, hoping to hear any merits/cautions about my system. I am currently building a relatively low-budget panel for my Lancair ES. I have a dual electric (Z-14) system with standard gauges for everything **except** the attitude indicator, which I replaced with a Dynon EFIS D-10. My rationale for replacing the attitude indicator was the negative reports I've heard/read/experienced with electric AI's. With the Dynon, I've got not only an attitude indicator, but also backups for several instruments (DG, airspeed, altititude, VSI, TC, etc.). I am banking on this combination being a better deal (probably MUCH better) than having an electric AI. I am instrument rated and plan to take my plane into "hard" IFR. Obviously, I am not relying solely on the Dynon for this. I also have the standard DG, TC, and compass in the standard configuration, as well as a TruTrak autopilot and a second TC in the copilot's seat. Even if the Dynon were to fail, I feel like I have a better IFR arrangement than my club's Cardinal, which has vacuum driven gyros, a standby vacuum system, and an electric TC. I don't think I would feel this way if I were overly reliant on the attitude indicator (in my case the Dynon) for flying in IMC. To me, flying in IMC requires a good scan and confidence in your ability to fly partial panel when the AI goes out. Having a great autopilot made obviously adds confidence as well. Any thoughts/concerns appreciated. Dan O'Brien Lancair Super ES ________________________________ Message 13 ____________________________________ Time: 08:03:14 PM PST US From: "Dave von Linsowe" Subject: Re: AeroElectric-List: Analog to digital converter --> AeroElectric-List message posted by: "Dave von Linsowe" What I had meant to say was: Thanks Bob! Dave Seems sending through a remote server does some strange stuff. Do not archive ----- Original Message ----- From: "David.vonLinsowe" Subject: Re: AeroElectric-List: Analog to digital converter > --> AeroElectric-List message posted by: "David.vonLinsowe" > > VGltZTogMDY6MTY6NTEgUE0gUFNUIFVTDQpGcm9tOiAiUm9iZXJ0IEwuIE51Y2tvbGxzLCBJSUki > IDxib2IubnVja29sbHNAY294Lm5ldD4NClN1YmplY3Q6IFJlOiBBZXJvRWxlY3RyaWMtTGlzdDog > QW5hbG9nIHRvIGRpZ2l0YWwgY29udmVydGVyDQoNCi0tPiBBZXJvRWxlY3RyaWMtTGlzdCBtZXNz > YWdlIHBvc3RlZCBieTogIlJvYmVydCBMLiBOdWNrb2xscywgSUlJIiBib2IubnVja29sbHNAY294 > Lm5ldA0KDQoNCiAgID4+PiBTaG9ydCBhbnN3ZXIgaXMgdGhhdCB0aGUgaGFyZHdhcmUgaXMgZWFz > eSBhbmQgY2hlYXAuDQogICAgVGVsbGluZyB0aGUgaGFyZHdhcmUgaG93IHRvIGRvIGl0J3Mgam9i > IGlzIHRoZSBjaGFsbGVuZ2luZw0KICAgIHBhcnQgYW5kIHdvdWxkIHByb2JhYmx5IG5lZWQgc29t > ZSBjb29wZXJhdGlvbiBvbiB0aGUgcGFydCBvZg0KICAgIE1yLiBZb3Vua2luLg0KDQogICAgQm9i > IC4gLiAuDQoNClRoYW5rIHlvdSBCb2IuDQoNCkRhdmUNCg0KRG8gbm90IGFyY2hpdmUNCg0KDQoN > Cg== ________________________________ Message 14 ____________________________________ Time: 08:12:09 PM PST US From: "Dave von Linsowe" Subject: Re: AeroElectric-List: New FAA AC On Amateur Built Aircraft --> AeroElectric-List message posted by: "Dave von Linsowe" So what happens if you build your airplane from scratch??? Dave Do not archive ----- Original Message ----- From: "glong2" Subject: RE: AeroElectric-List: New FAA AC On Amateur Built Aircraft > --> AeroElectric-List message posted by: "glong2" > > QC: > > I have the same problem. I finally went to the kit supplier (Lancair) and > they filled out the proper form (AC 8050-3) that I hope meets the FAA > requirement! > As I read the original requirement it did not require the form but said it > "could be used". When I applied for the registration the FAA came back and > said the original bill of sale was not good enough! > > > Eugene Long > Lancair Super ES > glong2@netzero.net ________________________________ Message 15 ____________________________________ Time: 08:17:58 PM PST US From: Speedy11@aol.com Subject: AeroElectric-List: (no subject) --> AeroElectric-List message posted by: Speedy11@aol.com I have three instruments available for an all-electric panel. They are new and have never been used. I got them with a project I bought and I've decided to install the Blue Mountain EFIS so I no longer need them. All are 14v unlighted. I will pay for insured Fedex shipping. I can send digital photos if desired. Instruments Available: One RC Allen Attitude Indicator model RCA26AK-4 Aircraft Spruce - $1785 Chief (new surplus) - $1675 American - $1695 Gulf Coast - $1895 My Price - $1300 with free shipping & no sales tax One RC Allen Directional Gyro model RCA15AK-2 Aircraft Spruce - $1695 Chief - $1689 American - $1425 Gulf Coast - $1895 My Price - $1100 with free shipping & no sales tax One RC Allen Turn Coordinator model 82A-11 Aircraft Spruce - $483 Chief - $515 American - $495 My Price - $350 with free shipping & no sales tax Buy all three for $2500 and save an additional $250. The prices are a very good value and the instruments are new. Payment is via cashiers check or I will ship COD if the buyer is willing to pay the COD charges. Once the buyer receives the instruments I will accept them back if shipped back within 2 days of delivery. If returned, shipping is at buyers expense and I will deduct my shipping costs from the amount paid. The buyer will need to call me if returning an instrument (s). If all are purchased for $2500, then all must be returned if any is returned. In other words, you can't buy all three and then return only one. Don't respond on Matronics - contact me via email at "Speedy11@aol.com" or by phone at 813-318-9074 or 813-732-7369. Stan Sutterfield Tampa, FL RV-8A QB ________________________________ Message 16 ____________________________________ Time: 08:42:05 PM PST US From: "William" Subject: Re: AeroElectric-List: New FAA AC On Amateur Built Aircraft --> AeroElectric-List message posted by: "William" Scratch built don't require bill of sale, different box is checked. Bill Schertz ----- Original Message ----- From: "Dave von Linsowe" Subject: Re: AeroElectric-List: New FAA AC On Amateur Built Aircraft > --> AeroElectric-List message posted by: "Dave von Linsowe" > > So what happens if you build your airplane from scratch??? > > Dave > > Do not archive > > > ----- Original Message ----- > From: "glong2" > To: > Subject: RE: AeroElectric-List: New FAA AC On Amateur Built Aircraft > > > > --> AeroElectric-List message posted by: "glong2" > > > > QC: > > > > I have the same problem. I finally went to the kit supplier (Lancair) and > > they filled out the proper form (AC 8050-3) that I hope meets the FAA > > requirement! > > As I read the original requirement it did not require the form but said it > > "could be used". When I applied for the registration the FAA came back and > > said the original bill of sale was not good enough! > > > > > > Eugene Long > > Lancair Super ES > > glong2@netzero.net > > ________________________________ Message 17 ____________________________________ Time: 09:40:05 PM PST US From: "Dave Grosvenor" Subject: Re: AeroElectric-List: Battery voltage on start --> AeroElectric-List message posted by: "Dave Grosvenor" Thanks Bob. That answers my question. The reason I asked was two fold. With my kit I was supplied with a 16Ah wet motorcycle battery. I know the advantages of using an RG battery, but decided to put this thing in and use it until it died because I have paid for it. I was doing more tests with my OV module glitch and put a recording scope on my bus. When I hit the start button, the battery voltage is dropping right down to 9 volts. The battery cranks the starter with enough enthusiasm to start the engine (Rotax starter draws 50A) but my second problem related to a Rotax engine information system called a FlyDat that I have fitted. It doesn't like the low voltage and resets itself. It takes 30 seconds to go though its initialisation process which means you don't see an oil press reading for at least 30 secs. I was wondering if a 16Ah RG battery will also suffer from the same sort of volt drop. I saw the specs on a Hawker RG battery which say it will deliver 680A for 30 secs before dropping to 7.2 volts but I wanted to know if it will deliver 50A for 10 secs without dropping substantially. Thanks to your reply and looking at the specs again I see the impedance is 7milliohms which will give me a 0.35V drop - I can live with that. Goodbye motorcycle battery! Thanks again Dave ----- Original Message ----- From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Battery voltage on start --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:46 AM 8/16/2003 +0200, you wrote: >--> AeroElectric-List message posted by: "Dave Grosvenor" > >Assuming you have a good battery, how much can you expect the battery >voltage to drop when you hit the starter (50 - 60Amps) for a few seconds? Depends on the battery. There is enough ENERGY in a string of d-size flashlight batteries to crank your engine. Problem is that these small cell are limited in the RATE at which energy can be delivered by a quality known as internal resistance or internal impedance. Further, their small size suggests a limited CAPACITY too . . . meaning that even if these cells would deliver useful output at 60A, your engine would need to start in a few revolutions. We bench test new 17 a.h. RG batteries with enough load to drop the terminal voltage to 8.5 volts. A really robust product will put out 600 amps. A 4-volt drop divided by 600 Amps yields a measured internal impedance on the order of 7 milliohms. Your Your hypothetical for 60A would yield 1/10 the voltage drop on the same battery so it might be expected to stay above 12 volts! As battery characteristics degrade with service or manufacturing techniques, you can EXPECT internal impedance to be higher. A really tired 17 a.h. RG battery will show an internal impedance of 20 milliohms (200A draw) and be pretty close to useless at this condition for larger engines. If you can get going with 60A of cranking current, the "tired" battery will still show a terminal voltage of 11.3 volts . . . Bigger batteries tend to have lower impedances. Products with less-than-the-best construction will have higher impedances . . . but for the purposes of discussing your question, about any RG battery from 10-32 a.h. range should start your engine with ease . . . Most aircraft engines crank in the 150-250A range and can be expected to show what the battery is made of. Your cranking requirements are so much lighter that you can expect to get good cranking performance from some relatively small and/or tired batteries. Bob . . . Bob . . . -------------------------------------------- ( Knowing about a thing is different than ) ( understanding it. One can know a lot ) ( and still understand nothing. ) ( C.F. Kettering ) -------------------------------------------- ________________________________ Message 18 ____________________________________ Time: 10:24:23 PM PST US From: drew.schumann@us.army.mil Subject: AeroElectric-List: soldering iron wattage --> AeroElectric-List message posted by: drew.schumann@us.army.mil In reading the instructions for building an RST Marker Beacon kit, they call out for a 35-80 watt pencil soldering iron. I have access to a 25 watt iron from Radio Shack. Looking through the kit, I don't see anything so big as to need all that extra wattage. Am I wrong in thinking I could do just as good a job with a 25 watt iron? Thanks, Drew ________________________________ Message 19 ____________________________________ Time: 11:41:00 PM PST US From: "Jim Jewell" Subject: Re: AeroElectric-List: soldering iron wattage --> AeroElectric-List message posted by: "Jim Jewell" Hi Drew, I suggest you consider getting a soldering iron of some what better quality than what you suggest is easily available to you. If you don't expect to do any other electronic projects at all, try to borrow a better unit. I built both of the RMI kits. When I started out on them I wasted money on a cheap iron. Fortunately it burned out before I got too far. After thinking about how it performed before it died on me, I decided that a hundred bucks was a small percentage of what the two kits cost. I bought a Weller adustable whattage unit that has electro static discharge protection. Right away I was surprised at how much better my soldering quality came out. Both of the RMI kits worked fine when powered up. I'm not so sure they would have without the better quailty unit. The kits are built and I now have a good soldering station that I find I am using much more than I expected. Have fun building, Jim in Kelowna ----- Original Message ----- From: Subject: AeroElectric-List: soldering iron wattage > --> AeroElectric-List message posted by: drew.schumann@us.army.mil > > In reading the instructions for building an RST Marker Beacon kit, they call out for a 35-80 watt pencil soldering iron. I have access to a 25 watt iron from Radio Shack. Looking through the kit, I don't see anything so big as to need all that extra wattage. Am I wrong in thinking I could do just as good a job with a 25 watt iron? > > Thanks, > > Drew > >