---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 12/30/02: 26 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:03 AM - toggle spacing (Robert Dickson) 2. 06:28 AM - A Question to End the Holiday Doldrums (Reid) 3. 06:42 AM - Re: A Question to End the Holiday Doldrums (Randy Pflanzer) 4. 06:50 AM - Airframe ground (Ed Kramer) 5. 06:55 AM - Re: A Question to End the Holiday Doldrums (KITFOXZ@aol.com) 6. 06:59 AM - Re: A Question to End the Holiday Doldrums (David Swartzendruber) 7. 07:02 AM - Re: A Question to End the Holiday Doldrums (KITFOXZ@aol.com) 8. 07:31 AM - Re: toggle spacing (Larry Bowen) 9. 08:03 AM - Re: A Question to End the Holiday Doldrums (Charlie and Tupper England) 10. 08:08 AM - Re: toggle spacing (Robert L. Nuckolls, III) 11. 08:23 AM - Over-voltage protection (again) (Gary Casey) 12. 08:41 AM - Re: Airframe ground (Robert L. Nuckolls, III) 13. 08:45 AM - Re: toggle spacing (Robert Dickson) 14. 09:40 AM - Re: toggle spacing (CBFLESHREN@aol.com) 15. 02:36 PM - SD-20 (Walter Casey) 16. 05:34 PM - GPS Antennas (Whollo80@aol.com) 17. 05:48 PM - Re: GPS Antennas (BobsV35B@aol.com) 18. 06:08 PM - Re: GPS Antennas (Whollo80@aol.com) 19. 07:01 PM - Re: GPS Antennas (Michel Therrien) 20. 08:19 PM - Checking the crowbar OV module (Ed Perry) 21. 09:09 PM - Re: Checking the crowbar OV module (Robert L. Nuckolls, III) 22. 09:13 PM - Re: SD-20 (Robert L. Nuckolls, III) 23. 09:14 PM - Re: SD-20 (Robert L. Nuckolls, III) 24. 09:34 PM - OV regulatro (Robert Kellar) 25. 10:43 PM - Re: SD-20 (Walter Casey) 26. 11:06 PM - Recombinant Gas Batteries (Walter Casey) ________________________________ Message 1 _____________________________________ Time: 06:03:17 AM PST US Subject: AeroElectric-List: toggle spacing From: "Robert Dickson" --> AeroElectric-List message posted by: "Robert Dickson" What are you folks using for toggle switch spacing on your panels? Also, anyone want to comment on how and why they grouped their switches? I'm using two toggles for mags/start and am generally following Z-11. After a very quiet week on this list, maybe this will get some chatter going and I can learn something I really need to know. TIA for your thoughts. Robert Dicksom RV-6A electrical ________________________________ Message 2 _____________________________________ Time: 06:28:04 AM PST US From: "Reid" Subject: AeroElectric-List: A Question to End the Holiday Doldrums --> AeroElectric-List message posted by: "Reid" If I wire a new 12-volt, 300-cranking amp battery in series with a new 12-volt, 1000-cranking amp battery, how many 24-volt cranking amps will be available for use? Reid Siebert ________________________________ Message 3 _____________________________________ Time: 06:42:25 AM PST US From: Randy Pflanzer Subject: Re: AeroElectric-List: A Question to End the Holiday Doldrums --> AeroElectric-List message posted by: Randy Pflanzer Uh....enough so that the prop will spin fast enough for powered flight with the ignition off??? Sure puts my 17 AH battery to shame. Randy (F1 Rocket #95) http://mywebpages.comcast.net/f1rocket/ ----- Original Message ----- From: Reid Subject: AeroElectric-List: A Question to End the Holiday Doldrums > --> AeroElectric-List message posted by: "Reid" > > > If I wire a new 12-volt, 300-cranking amp battery > in series with a new 12-volt, 1000-cranking amp battery, > how many 24-volt cranking amps will be available for use? > > Reid Siebert > > > _- > =======================================================================_ > _-> _- > ======================================================================_- = - The AeroElectric-List Email Forum - > _- > ======================================================================_- = !! NEWish !! > _- > ======================================================================_- = List Related Information > _- > ====================================================================== > > > > ________________________________ Message 4 _____________________________________ Time: 06:50:57 AM PST US From: "Ed Kramer" Subject: AeroElectric-List: Airframe ground --> AeroElectric-List message posted by: "Ed Kramer" List, I have a question. My original plan was to use the airframe as the ground for things such as the strobe power supply, nav-lights ect. I've been told radio noise can be eliminated by running a ground wire directly from the unit to the firewall. If this is true what kind of a ground wire is used? (just insulated or must it be shielded). Thanks! Ed Kramer West Seneca, NY Zenith CH 701 edkramer@prodigy.net ________________________________ Message 5 _____________________________________ Time: 06:55:56 AM PST US From: KITFOXZ@aol.com Subject: Re: AeroElectric-List: A Question to End the Holiday Doldrums --> AeroElectric-List message posted by: KITFOXZ@aol.com In a message dated 12/30/2002 9:28:40 AM Eastern Standard Time, Reid@Siebert.com writes: > > If I wire a new 12-volt, 300-cranking amp battery > in series with a new 12-volt, 1000-cranking amp battery, > how many 24-volt cranking amps will be available for use? > > Reid Siebert > > Reid, As you state: "in series" you will have only the Max capacity of the smaller battery. You will have 300 amps available at 24 volts. After that, the voltage will fall to something far less than 24 V and nearly 12 V for the duration of the capacity of the 1000 amp battery. This configuration will likely destroy the 300 amp battery. In series, once the 300 amp battery's charge is depleted, the load current of the larger battery will try to reverse charge the depleted battery. Not good at all! John P. Marzluf Columbus, Ohio Outback, (out back in the garage) ________________________________ Message 6 _____________________________________ Time: 06:59:58 AM PST US From: "David Swartzendruber" Subject: RE: AeroElectric-List: A Question to End the Holiday Doldrums --> AeroElectric-List message posted by: "David Swartzendruber" I believe your 17AH battery can deliver 300 cranking amps as well. The two batteries in series will be limited by the 300 cranking amp battery, so your 17AH battery has nothing to be ashamed of. David Swartzendruber Wichita > > Uh....enough so that the prop will spin fast enough for powered flight > with the ignition off??? > > Sure puts my 17 AH battery to shame. > > Randy > (F1 Rocket #95) > http://mywebpages.comcast.net/f1rocket/ > > > > If I wire a new 12-volt, 300-cranking amp battery > > in series with a new 12-volt, 1000-cranking amp battery, > > how many 24-volt cranking amps will be available for use? > > > > Reid Siebert > > ________________________________ Message 7 _____________________________________ Time: 07:02:39 AM PST US From: KITFOXZ@aol.com Subject: Re: AeroElectric-List: A Question to End the Holiday Doldrums --> AeroElectric-List message posted by: KITFOXZ@aol.com In a message dated 12/30/2002 9:28:40 AM Eastern Standard Time, Reid@Siebert.com writes: > > If I wire a new 12-volt, 300-cranking amp battery > in series with a new 12-volt, 1000-cranking amp battery, > how many 24-volt cranking amps will be available for use? > > Reid Siebert > > Extreme caution should be exercised when charging or discharging any batteries in series! Even innocent child's toys can catch fire by mixing "drycell" batteries of different chemistry/capacity/characteristics! John P. Marzluf Columbus, Ohio Outback, (out back in the garage) ________________________________ Message 8 _____________________________________ Time: 07:31:18 AM PST US From: "Larry Bowen" Subject: RE: AeroElectric-List: toggle spacing --> AeroElectric-List message posted by: "Larry Bowen" I drilled mine the other day...0.8 inches on center. - Larry Bowen Larry@BowenAero.com http://BowenAero.com > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On > Behalf Of Robert Dickson > Sent: Monday, December 30, 2002 9:02 AM > To: Aeroelectric List > Subject: AeroElectric-List: toggle spacing > > > --> AeroElectric-List message posted by: "Robert Dickson" > --> > > What are you folks using for toggle switch spacing on your > panels? Also, > anyone want to comment on how and why they grouped their switches? > > I'm using two toggles for mags/start and am generally following Z-11. > > After a very quiet week on this list, maybe this will get > some chatter going and I can learn something I really need to know. > > TIA for your thoughts. > > Robert Dicksom > RV-6A electrical ________________________________ Message 9 _____________________________________ Time: 08:03:29 AM PST US From: Charlie and Tupper England Subject: Re: AeroElectric-List: A Question to End the Holiday Doldrums --> AeroElectric-List message posted by: Charlie and Tupper England Reid wrote: > --> AeroElectric-List message posted by: "Reid" > > > If I wire a new 12-volt, 300-cranking amp battery > in series with a new 12-volt, 1000-cranking amp battery, > how many 24-volt cranking amps will be available for use? > > Reid Siebert > 300 ________________________________ Message 10 ____________________________________ Time: 08:08:58 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: toggle spacing --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:01 AM 12/30/2002 -0500, you wrote: >--> AeroElectric-List message posted by: "Robert Dickson" > > >What are you folks using for toggle switch spacing on your panels? Also, >anyone want to comment on how and why they grouped their switches? > >I'm using two toggles for mags/start and am generally following Z-11. > >After a very quiet week on this list, maybe this will get some chatter going >and I can learn something I really need to know. I use .8" spacing for the switches we sell. I've published some exemplar layouts for switch panels at http://216.55.140.222/temp//Switches.pdf If the switches go in a single row, I try to organize switches used pre/post-flight separate from those used in flight. Two row switch panels might put the engine and DC power switches above those used for lighting and other functions likely to be used en route. Bob . . . ________________________________ Message 11 ____________________________________ Time: 08:23:54 AM PST US From: "Gary Casey" Subject: AeroElectric-List: Over-voltage protection (again) --> AeroElectric-List message posted by: "Gary Casey" In reading all the submissions about over-voltage protection I have come up with a question. It is based on the assumption that the only failure that can cause an over-voltage condition is that of the voltage regulator, assuming that the regulator is external or otherwise not internally powered. The typical over-voltage protection circuit is in series with the regulator and disconnects the power feed to the field. I'm assuming that the protection device could be on either side of the regulator. Question: Why not just install a second regulator in series with the first? The second one could be adjusted to a somewhat higher voltage than the first one and could be designed to provide an output for a warning light if it came on line. Therefore, a (primary) regulator failure would result in a system voltage of, say, 15 volts instead of 14 and a warning indicator. Nothing would have to be done by the pilot and he could complete his flight without worry of running out of battery. This would seem like a more elegant solution than to just kill the alternator if the voltage regulator fails, which only replaces one emergency with another less urgent one. Gary Casey ________________________________ Message 12 ____________________________________ Time: 08:41:26 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Airframe ground --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:49 AM 12/30/2002 -0500, you wrote: >--> AeroElectric-List message posted by: "Ed Kramer" > >List, > I have a question. My original plan was to use the airframe as the > ground for things such as the strobe power supply, nav-lights ect. I've > been told radio noise can be eliminated by running a ground wire directly > from the unit to the firewall. If this is true what kind of a ground wire > is used? (just insulated or must it be shielded). You use the same wire to "ground" things as you use to "power" things . . . shielded wire is used only when the installation instructions for the device call for it. Bob . . . ________________________________ Message 13 ____________________________________ Time: 08:45:28 AM PST US Subject: Re: AeroElectric-List: toggle spacing From: "Robert Dickson" --> AeroElectric-List message posted by: "Robert Dickson" Bob Thanks! that's EXACTLY what I was looking for. Robert Dickson RV-6A electrical do not archive ---------- >From: "Robert L. Nuckolls, III" >To: aeroelectric-list@matronics.com >Subject: Re: AeroElectric-List: toggle spacing >Date: Mon, Dec 30, 2002, 11:07 AM > > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > At 09:01 AM 12/30/2002 -0500, you wrote: >>--> AeroElectric-List message posted by: "Robert Dickson" >> >> >>What are you folks using for toggle switch spacing on your panels? Also, >>anyone want to comment on how and why they grouped their switches? >> >>I'm using two toggles for mags/start and am generally following Z-11. >> >>After a very quiet week on this list, maybe this will get some chatter going >>and I can learn something I really need to know. > > I use .8" spacing for the switches we sell. I've published > some exemplar layouts for switch panels at > > http://216.55.140.222/temp//Switches.pdf > > If the switches go in a single row, I try to organize > switches used pre/post-flight separate from those used > in flight. Two row switch panels might put the engine > and DC power switches above those used for lighting > and other functions likely to be used en route. > > Bob . . . > > > ________________________________ Message 14 ____________________________________ Time: 09:40:37 AM PST US From: CBFLESHREN@aol.com Subject: Re: AeroElectric-List: toggle spacing --> AeroElectric-List message posted by: CBFLESHREN@aol.com In a message dated 12/30/2002 9:04:02 AM Eastern Standard Time, robert@thenews-journal.com writes: > >What are you folks using for toggle switch spacing on your panels? Hi Robert, assuming you are not in dire need of EVERY square millimeter of your panel space, the most relevant affect dictating minimum spacing (since you're not building a Certificated A/C) on the front of the panel is your finger size/length. Unless you want to make the concerted effort of using only the tip of your index finger & thumb, locate your switches at least far enough apart so you can comfortably cycle the switches without cycling it's neighbor . You can "slot" a piece of scrap material, install three switches in the slot, chuck it up in your vice & cycle the middle switch in a comfortable manner. Try left & right hands. At least a few hairs greater distance than it takes to not disturb switches 1 and 3 is your minimum clearance. Obviously switch type can limit spacing behind the panel (i.e. a typical 4 pole toggle switch is 1.5" wide). Rocker type switches are typically smaller & selected with just a finger tip so they are often the choice for tighter spacing. Wire routing & the way the wires attach to the switch can also influence spacing. At a minimum the switches should never touch each other behind the panel. > Also, anyone want to comment on how and why they grouped their switches? In turbulence you don't want to have to actually read what a given switch's function is. If you have 12 similar switches in a row , you will have a hard time actually counting "5" from either end. So! Grouping "choices" are only limited by your imagination. Landing, taxi, strobe and nav (position) lights would be a logical "group" separated from a continuing "row" by at least one switch hole spacing being blank. Longer "rows" of switches are dealt with by occasionally installing a switch with a differently designed lever or any one of a variety switch guards or at least a different color. This way you can quickly count 2 from the right of "this" switch or 3 from the left of that switch . Obviously never include batt master or buss switches or fuel boost or transfer pump switches where they could possibly be confused with anything else ! I have not checked lately but I'm sure Bob addresses all of this somewhere in the "Connection" publication. I think that's where I learned it ! Hope my 2 cent's worth is helpful . Good luck Robert & Happy New Year ! Chris Fleshren ________________________________ Message 15 ____________________________________ Time: 02:36:27 PM PST US Subject: AeroElectric-List: SD-20 From: Walter Casey --> AeroElectric-List message posted by: Walter Casey On page 17-9 of "Electrical System Reliability" Bob recommends an SD-20 20A backup alternator. I can't find this alternator on the B&C web site. Is this a discontinued item or what? Best wishes Walter ******************************************** * Walter Casey * * 6528 S. Oneida Ct. * * Englewood, CO 80110-4617 USA * * * * Phone (303) 771-0815 * * FAX (303) 220-1477 * * eMail mikec@caseyspm.com * ******************************************** ________________________________ Message 16 ____________________________________ Time: 05:34:54 PM PST US From: Whollo80@aol.com Subject: AeroElectric-List: GPS Antennas --> AeroElectric-List message posted by: Whollo80@aol.com I'm using a Garmin 90 and sometimes lose coverage on cloudy days. Would using one of the externally mounted antennas improve my coverage? Everything that I see in Aircraft Spruce is a little bit on the expensive side. Any thoughts? Bill ________________________________ Message 17 ____________________________________ Time: 05:48:53 PM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: GPS Antennas --> AeroElectric-List message posted by: BobsV35B@aol.com In a message dated 12/30/02 7:36:06 PM Central Standard Time, Whollo80@aol.com writes: > I'm using a Garmin 90 and sometimes lose coverage on cloudy days. Would > using > one of the externally mounted antennas improve my coverage? Everything that > I > see in Aircraft Spruce is a little bit on the expensive side. Any thoughts? Good Evening Bill, The clouds should have absolutely nothing to do with your GPS coverage. However, getting a full view of the sky is always a good idea. The 90 was a good unit in it's day and still has the capability of providing useful information, but the technology curve is still rising quite steeply on such equipment. You might consider upgrading to something like the Garmin 196. Any remote antenna that will allow a better view of the sky will make the 90 work a bit better. I don't know whether an active antenna will help with the 90 or not, but why don't you call the Garmin service number? I have found them to be easy to get hold of and full of good information. I added an active antenna for use with my Trimble 2000 Approach Plus. That old antique had it's performance noticeably improved by the addition. Look up Garmin at: www.garmin.com They have data there as to the phone numbers to call. Happy Skies, Old Bob ________________________________ Message 18 ____________________________________ Time: 06:08:56 PM PST US From: Whollo80@aol.com Subject: Re: AeroElectric-List: GPS Antennas --> AeroElectric-List message posted by: Whollo80@aol.com Thanks Bob, like always you are a great help. Bill ________________________________ Message 19 ____________________________________ Time: 07:01:26 PM PST US From: Michel Therrien Subject: Re: AeroElectric-List: GPS Antennas --> AeroElectric-List message posted by: Michel Therrien I bought a remote amplified antenna from GPSGeek on eBay. 20$ and it performs as well as my other remote Garmin amplified antenna (I have one in each car). Michel --- BobsV35B@aol.com wrote: > --> AeroElectric-List message posted by: > BobsV35B@aol.com > > In a message dated 12/30/02 7:36:06 PM Central > Standard Time, > Whollo80@aol.com writes: > > > I'm using a Garmin 90 and sometimes lose coverage > on cloudy days. Would > > using > > one of the externally mounted antennas improve my > coverage? Everything that > > I > > see in Aircraft Spruce is a little bit on the > expensive side. Any thoughts? > > Good Evening Bill, > > The clouds should have absolutely nothing to do with > your GPS coverage. > However, getting a full view of the sky is always a > good idea. The 90 was a > good unit in it's day and still has the capability > of providing useful > information, but the technology curve is still > rising quite steeply on such > equipment. You might consider upgrading to something > like the Garmin 196. > > Any remote antenna that will allow a better view of > the sky will make the 90 > work a bit better. I don't know whether an active > antenna will help with the > 90 or not, but why don't you call the Garmin service > number? I have found > them to be easy to get hold of and full of good > information. > > I added an active antenna for use with my Trimble > 2000 Approach Plus. That > old antique had it's performance noticeably improved > by the addition. > > Look up Garmin at: HREF="www.garmin.com">www.garmin.com > > They have data there as to the phone numbers to > call. > > Happy Skies, > > Old Bob > > > > Click on the > this > generous > _-> > - > Contributions > any other > Forums. > > latest messages. > List members. > > http://www.matronics.com/subscription > http://www.matronics.com/FAQ/AeroElectric-List.htm > Digests:http://www.matronics.com/digest/aeroelectric-list > http://www.matronics.com/archives > http://www.matronics.com/photoshare > http://www.matronics.com/emaillists > > > > > ===== ---------------------------- Michel Therrien CH601-HD http://mthobby.pcperfect.com/ch601 http://www.zenithair.com/bldrlist/profiles/mthobby http://pages.infinit.net/mthobby ________________________________ Message 20 ____________________________________ Time: 08:19:44 PM PST US From: "Ed Perry" Subject: AeroElectric-List: Checking the crowbar OV module --> AeroElectric-List message posted by: "Ed Perry" Is there any convenient way to check the OV module for proper operation? Ed Perry eperry@san.rr.com ________________________________ Message 21 ____________________________________ Time: 09:09:22 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Checking the crowbar OV module --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:21 PM 12/30/2002 -0800, you wrote: >--> AeroElectric-List message posted by: "Ed Perry" > >Is there any convenient way to check the OV module for proper operation? >Ed Perry >eperry@san.rr.com See notes section of http://www.aeroelectric.com/articles/crowbar.pdf Bob . . . ________________________________ Message 22 ____________________________________ Time: 09:13:16 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: SD-20 --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 03:34 PM 12/30/2002 -0700, you wrote: >--> AeroElectric-List message posted by: Walter Casey > >On page 17-9 of "Electrical System Reliability" Bob recommends an SD-20 >20A backup alternator. >I can't find this alternator on the B&C web site. >Is this a discontinued item or what? >Best wishes >Walter Try http://www.bandcspecialty.com/cgi-bin/ez-catalog/cat_display.cgi?2X358218 Bob . . . ________________________________ Message 23 ____________________________________ Time: 09:14:12 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: SD-20 --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 03:34 PM 12/30/2002 -0700, you wrote: >--> AeroElectric-List message posted by: Walter Casey > >On page 17-9 of "Electrical System Reliability" Bob recommends an SD-20 >20A backup alternator. >I can't find this alternator on the B&C web site. >Is this a discontinued item or what? >Best wishes >Walter On other pages I show an SD-8 which is considerably less expensive and lighter . . . are you sure you NEED one as big as the SD-20? Bob . . . ________________________________ Message 24 ____________________________________ Time: 09:34:01 PM PST US From: "Robert Kellar" Subject: AeroElectric-List: OV regulatro --> AeroElectric-List message posted by: "Robert Kellar" Thank you for you quick response. I missed the part about the breaker in the instructions. I'll install a breaker and fly some more and then let you know here on the list. Re: Voltage before the fuse blows...I am too busy flying the takeoff to notice. I'll bring a passenger to monitor this value. Bob Kellar ----- Original Message ----- From: "Robert L. Nuckolls, III" Subject: Re: 10179 Kellar > At 10:51 PM 12/29/2002 -0800, you wrote: > >Below is the result of your inquiry. It was submitted by > >Robert Kellar (rkellar@attbi.com) on Sunday, December 29, 2002 at 22:51:40 > > > > >Sunday, December 29, 2002 > > > >Robert Kellar > > > >, > >Email: rkellar@attbi.com > >Comments/Questions: I am using your voltage regulator LR3B-14 in my > >RV6. Purchased 2 years ago. Worked wonderfully until 2 months ago. On > >multiple occasions the 5A fuse from the bus to the master switch to > >terminal 6 blows. > > This fuse should have been a circuit breaker . . . all of our > installation drawings show a breaker used with any form of > crowbar overvoltage protection. > > > When not blown the voltage regulator functions perfectly 20+ amps > > charge then cycles down to less than 5 amps for flight. Usually the fuse > > lasts for 1 hr or less and then with the next flight, as I take off the > > fuse will blow and the blinking warning light comes on. Replace the fuse > > and I can fly again for awhile. I have inspected everything in the panel, > > wires, connections etc looking for a possible short or failure. My > > question is...Is there anything internal to the unit that could cause > > this intermittent failure? If not, I will continue my investigation of > > all the wire out to the alternator looking for a possible intermittent short. > > Do you have a voltmeter in the airplane? What does it read > just before the ov system trips? > > > Thank you for your response and all the help provided on the net and in > > your electical manual and diagrams. > > My pleasure sir. > > I will invite you to join us on the AeroElectric List > to continue this and similar discussions. It's useful to > share the information with as many folks as possible. > You can join at . . . > > http://www.matronics.com/subscribe/ > > Thanks! > > Bob . . . > > |---------------------------------------------------| > | A lie can travel half way around the world while | > | the truth is till putting on its shoes . . . | > | -Mark Twain- | > |---------------------------------------------------| > ________________________________ Message 25 ____________________________________ Time: 10:43:43 PM PST US Subject: Re: AeroElectric-List: SD-20 From: Walter Casey --> AeroElectric-List message posted by: Walter Casey Thanks Bob, No I am not sure. I have just started investigating. Best wishes, Walter On Monday, December 30, 2002, at 10:12 PM, Robert L. Nuckolls, III wrote: > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > At 03:34 PM 12/30/2002 -0700, you wrote: >> --> AeroElectric-List message posted by: Walter Casey >> >> >> On page 17-9 of "Electrical System Reliability" Bob recommends an >> SD-20 >> 20A backup alternator. >> I can't find this alternator on the B&C web site. >> Is this a discontinued item or what? >> Best wishes >> Walter > > On other pages I show an SD-8 which is considerably less > expensive and lighter . . . are you sure you NEED one > as big as the SD-20? > > Bob . . . > > ________________________________ Message 26 ____________________________________ Time: 11:06:56 PM PST US Subject: AeroElectric-List: Recombinant Gas Batteries From: Walter Casey --> AeroElectric-List message posted by: Walter Casey In the literature Bob appears to recommend the RG batteries. The problem is that I have searched both B&C and AircraftSpruce but can't find the RG batteries. Please help. Walter