---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 02/15/08: 23 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:40 AM - Loran Antenna (Don Curry) 2. 06:05 AM - Re: Boeing 767 speeds (was External antennas) () 3. 06:31 AM - Re: Loran Antenna (rampil) 4. 06:45 AM - (Robert L. Nuckolls, III) 5. 06:57 AM - Re: Re: Boeing 767 speeds (was External antennas) (Mike) 6. 06:58 AM - Re: Re: Loran Antenna (BobsV35B@aol.com) 7. 07:07 AM - Re: Loran Antenna (Mike) 8. 07:11 AM - Re: Re: Boeing 767 speeds (was External antennas) (Ernest Christley) 9. 07:35 AM - Re: Re: Boeing 767 speeds (was External antennas) (Matt Prather) 10. 07:45 AM - Tefzel dielectric strength (Sam Hoskins) 11. 10:37 AM - Re: Tefzel dielectric strength (rampil) 12. 10:43 AM - Re: Re: Why can't the tower hear me? (Buckaroo Banzai) 13. 10:52 AM - Re: Tefzel dielectric strength (Robert L. Nuckolls, III) 14. 11:45 AM - Re: Tefzel dielectric strength (George, Neal E Capt MIL USAF 605TES/TSI) 15. 12:55 PM - Re: Tefzel dielectric strength (Robert L. Nuckolls, III) 16. 03:24 PM - Re: Tefzel dielectric strength (Sam Hoskins) 17. 04:54 PM - Re: Tefzel dielectric strength (rampil) 18. 05:37 PM - Re: Re: Why can't the tower hear me? (Robert Feldtman) 19. 06:58 PM - Re: Re: Boeing 767 speeds (was External antennas) (Gilles Thesee) 20. 07:10 PM - Re: Re: Boeing 767 speeds (was External antennas) (Gilles Thesee) 21. 07:16 PM - Re: Re: Tefzel dielectric strength (Robert L. Nuckolls, III) 22. 07:33 PM - Re: Tefzel dielectric strength (Robert L. Nuckolls, III) 23. 08:31 PM - Re: Re: Boeing 767 speeds (was External antennas) (Ernest Christley) ________________________________ Message 1 _____________________________________ Time: 05:40:02 AM PST US From: "Don Curry" Subject: AeroElectric-List: Loran Antenna Many believe Loran is dead technology, but I'm not one of them. Old, yes; stale, yes; but dead, no! In fact, I'm including a KLN-88 in a panel project on a Tiger. Which brings me to my question. I have room in my wingtips for the KA-84 antenna, but I'm concerned about reception. Is "ground plane" an issue with Loran? If so, would the wingtip location provide sufficient ground plane? Are there any other reasons to NOT consider the wingtips as a location for the antenna? Also, while I don't currently have strobe lights in my wingtips, I would like to retain the option of installing them in the future. Since I'm certain that strobe lights would interfere with Loran reception, is there some type of shielding that I could install along with the strobes to prevent the interference? Don ________________________________ Message 2 _____________________________________ Time: 06:05:32 AM PST US From: Subject: AeroElectric-List: Re: Boeing 767 speeds (was External antennas) Mike: Not sure what your talking about, but I wrote or should have wrote 460kt (true). I fly both the 757/767. I never do more than 250kias below FL100. We usually climb at about 280-320 kias to FL250. Than we go to Mach above approx FL270. Normal econ cruise is about mach 0.82. Mach 0.82 = about 280 kias, 450 ktas @ FL350. Indicated a/s depends on altitude. Red line, Vmo/Mmo is a moving target. Max Vmo/Mmo is no longer a Boeing Limit to memorize, because it moves around and its always displayed on both the mechanical airspeed indicator and the speed tape on the EFIS. Off the top of my head @ sea level its approx 350 kias/M.86 range for the B757. The limit is the lower of the two limits, Vmo/Mmo. Kts are for lower altitudes and Mach for higher altitudes above FL270. Of course we don't do 350 kts on the deck, but it would be fun. During a pilot oral exam there is no Vmo/Mmo to remember. You don't have to memorize stuff that is right in front of you. Good thing, less to memorize. Other speeds are in the checklist. My point is the antenna does not care what size plane it is on. Drag is drag. Think about it, Mike Cheers George ATP/757/757/CE500 >From: "Mike" >Subject: Re: External antennas on composite plane >460 kts TAS not indicated. The indicated speed of a >757 or 767 is 360kias. >Think about it, Mike --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. ________________________________ Message 3 _____________________________________ Time: 06:31:45 AM PST US Subject: AeroElectric-List: Re: Loran Antenna From: "rampil" Loran IS dead, but still walking. The sizing mechanics of VLF antenna is completely different than VHF (com/nav) or Microwave (GPS). In the latter two, a ground plane should be in the range of 1/4-1/2 wavelength radius , depending on config of antenna. In VLF, wavelength may be 100-1000x size of your Tiger. Best Loran antenna is a trailing wire 1 half mile long ;-) No ground required! I have an uninstalled 618, can I sell it to you? Nice paperweight! -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=164186#164186 ________________________________ Message 4 _____________________________________ Time: 06:45:20 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Comments/Questions: How many terminals would you say is the max on the hot side of a batt contactor?(4?) Ideally, just one. There are two considerations for stacking things on the single stud.: (a) the more wires . . . presumably most of them 'fat' wires . . . the greater the torque-moments that tend to unwind the nut. Obviously, if the installer makes a considered effort to insure integrity of the join (thread locker, locking nut, making up the joint to the max recommended torque value for the materials, etc) the lower the probability of in-service loosening. Of course, supporting the exiting wires soon after they depart the nut will reduce the free-mass waving in the breeze and reacting on the join. (b) thread length of the exposed terminal is an obvious mechanical limit. The books tell us that we should drive for a minimum headroom of 1.5 exposed threads sticking out of the nut when we're finished. Quite often, this is the biggest limiting factor for how many terminals get stacked on the stud. Stud length can vary significantly between brands for similar devices. See: http://www.aeroelectric.com/Pictures/Contactors/stud_length.jpg http://www.aeroelectric.com/Pictures/Contactors/strtrctr.jpg http://www.aeroelectric.com/Pictures/Contactors/6041_Contactor.jpg There is no industry-wide practice for setting limits on how much 'stuff' you stack on these studs. It's up to the designer/installer to be cognizant of the conditions that tend to undo the design and exercise due diligence in crafting the joint. Where can I find the appendix for suppliers? On the 'net. In early issues of the 'Connection I offered a listing of handy suppliers for tools, materials and parts useful to the OBAM aircraft community. That was an exceedingly difficult list to keep up to date so, as the first paragraph of Appendix Z points out, we deleted appendices A, C and K in favor of offering those coverages on the 'net. And finally, is there a chart of recommended circuit breakers for a specific AWG, you say 5 amp for 22awg, what are other recommendations? Breakers protect wires . . . period. Maximum recommended loads on any given wire are NOT based on danger to the wire (copper) but to the insulation. For example, in this slide taken from my weekend seminar presentation . . . http://www.aeroelectric.com/Pictures/Wire/22AWG_20A.pdf we see a 22AWG wire loaded to 20A on the bench. The insulation temperature isn't even close to being over-stressed. It's got another 40C to go! At the other end of the spectrum, cross country power lines that make up the nation's distribution grid are oft cited as being 'dangerously overloaded'. Are they at risk for parting the line due to melting? No, their temperature rise is so high that coefficient of expansion effects are causing the wires to sag into trees. The risk is for tripping the line off when system arcs to ground through a tree. I'm recalling that the great Northeast Blackout a few years ago was triggered by a power line dropping into a tree up in Canada. Yes, there's a VERY conservative wire rating table in the book and repeated here: http://www.aeroelectric.com/Pictures/Wire/Wire_Table.jpg Here we see that the 22AWG wire is industry rated (or perhaps de-rated?) to 5A capacity. This isn't a 'rule of thumb'. It's the product of a process that says based on our experience (airplanes with environments that range from -55C to 100C) and bundles of perhaps hundreds of wires, running no more than 5A through a 22AWG wire offers a 99.999% degree of confidence for satisfactory-lifetime-of-the-airframe-performance (SLOTAP). Should you choose to tailor your own use of 22AWG wire, there are innumerable tutorials on how this is accomplished . . . but I'll suggest your time is better spent getting all the rivet heads smooth and the upholstery seams straight. Further to this, if I have a 2 amp load on a 22AWG, do I still need 5 amp CB to protect it, or is it OK if the breaker doesn't exceed 5 amps, but is lets say, 3 amps? As discussed above, you can do about anything you want in terms of protecting any give chunk of wire. And based on your considered analysis of how the wire is used in YOUR airplane, the breaker might be anything from 1 to 10 amps! But breakers below 5A are more expensive and breakers above 5A start pushing out into the corners of the performance envelope that reduce your SLOTAP confidence. Love the book, learned more than in 2 years at college! I'm pleased that you're getting a good return on your investment. Bob . . . ________________________________ Message 5 _____________________________________ Time: 06:57:24 AM PST US From: "Mike" Subject: RE: AeroElectric-List: Re: Boeing 767 speeds (was External antennas) George, I only pointed it out because I assumed that you were trying to illustrate the speed effect of a higher speed aircraft on an antenna and its relationship to drag/speed. You wrote 460 knots. I was just trying to point out that as it relates to the antenna drag, you use indicated speed not True Airspeed in that speed range (not true for high mach numbers). I then pointed out that the 757 only does 350=92ish Knots Indicated. Mike The dark side (Airbus) -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of gmcjetpilot@yahoo.com Sent: Friday, February 15, 2008 7:02 AM Subject: AeroElectric-List: Re: Boeing 767 speeds (was External antennas) Mike: Not sure what your talking about, but I wrote or should have wrote 460kt (true). I fly both the 757/767. I never do more than 250kias below FL100. We usually climb at about 280-320 kias to FL250. Than we go to Mach above approx FL270. Normal econ cruise is about mach 0.82. Mach 0.82 = about 280 kias, 450 ktas @ FL350. Indicated a/s depends on altitude. Red line, Vmo/Mmo is a moving target. Max Vmo/Mmo is no longer a Boeing Limit to memorize, because it moves around and its always displayed on both the mechanical airspeed indicator and the speed tape on the EFIS. Off the top of my head @ sea level its approx 350 kias/M.86 range for the B757. The limit is the lower of the two limits, Vmo/Mmo. Kts are for lower altitudes and Mach for higher altitudes above FL270. Of course we don't do 350 kts on the deck, but it would be fun. During a pilot oral exam there is no Vmo/Mmo to remember. You don't have to memorize stuff that is right in front of you. Good thing, less to memorize. Other speeds are in the checklist. My point is the antenna does not care what size plane it is on. Drag is drag. Think about it, Mike Cheers George ATP/757/757/CE500 >From: "Mike" >Subject: Re: External antennas on composite plane >460 kts TAS not indicated. The indicated speed of a >757 or 767 is 360kias. >Think about it, Mike _____ Be a better friend, newshound, and "http://www.matronics.com/Navigator?AeroElectric-List"http://www.matroni cs.com/Navigator?AeroElectric-List "http://forums.matronics.com"http://forums.matronics.com "http://www.matronics.com/contribution"http://www.matronics.com/contribu tion 10/2/2007 11:10 AM 10/2/2007 11:10 AM ________________________________ Message 6 _____________________________________ Time: 06:58:33 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re: Loran Antenna Good Morning Ira, I suppose this will start an argumentative string, but I agree with you. For the time being, LORAN as we have used it, is dead. There may be something new on the horizon, but the best currently available LORAN set can't hold a candle to a 100 dollar handheld from K-Mart. The newly proposed eLORAN (Enhanced Loran) is being proposed primarily as device to back up the timing and coordination capabilities of GPS. It is not meant to be a primary navigation device. I realize that the engineers will undoubtedly come up with newer antenna systems, but when eLoran was first proposed several years ago, the suggested antenna array was bigger than a Bonanza. The KLN-88 is a very nice component to use with a flight management system. It does have the capability of feeding data to many sophisticated navigation devices that were in common use twenty years ago. My feeling is that it belongs in a museum to be used to point out how much better are the devices we currently use. Do Not Archive Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator 628 West 86th Street Downers Grove, IL 60516 630 985-8502 Stearman N3977A Brookeridge Air Park LL22 In a message dated 2/15/2008 8:38:59 A.M. Central Standard Time, ira.rampil@gmail.com writes: --> AeroElectric-List message posted by: "rampil" Loran IS dead, but still walking. The sizing mechanics of VLF antenna is completely different than VHF (com/nav) or Microwave (GPS). In the latter two, a ground plane should be in the range of 1/4-1/2 wavelength radius , depending on config of antenna. In VLF, wavelength may be 100-1000x size of your Tiger. Best Loran antenna is a trailing wire 1 half mile long ;-) No ground required! I have an uninstalled 618, can I sell it to you? Nice paperweight! -------- Ira N224XS **************The year's hottest artists on the red carpet at the Grammy Awards. Go to AOL Music. (http://music.aol.com/grammys?NCID=aolcmp00300000002565) ________________________________ Message 7 _____________________________________ Time: 07:07:36 AM PST US From: "Mike" Subject: RE: AeroElectric-List: Loran Antenna Don, A more constructive response would have been something like this, nice multi-chain (KLN-88) Loran and it works well. Because of the FREQ range that system works in it is highly susceptible to poor gain and interference with the short antennas required for aircraft. Many Lorans require an amplifier/processor to enhance the signal to make it usable in aircraft. Most of the hard core Loran users have experienced reception problems with loran in clouds, prcip, ect. I have not seen, installed, or tested an internally mounted Loran antenna but my Guess is the performance would be reduced, possibly to less then acceptable. Mike And like you I like a GOOD Loran (unlike the 614) for area navigation. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Don Curry Sent: Friday, February 15, 2008 6:36 AM Subject: AeroElectric-List: Loran Antenna Many believe Loran is dead technology, but I'm not one of them. Old, yes; stale, yes; but dead, no! In fact, I'm including a KLN-88 in a panel project on a Tiger. Which brings me to my question. I have room in my wingtips for the KA-84 antenna, but I'm concerned about reception. Is "ground plane" an issue with Loran? If so, would the wingtip location provide sufficient ground plane? Are there any other reasons to NOT consider the wingtips as a location for the antenna? Also, while I don't currently have strobe lights in my wingtips, I would like to retain the option of installing them in the future. Since I'm certain that strobe lights would interfere with Loran reception, is there some type of shielding that I could install along with the strobes to prevent the interference? Don 10/2/2007 11:10 AM 10/2/2007 11:10 AM ________________________________ Message 8 _____________________________________ Time: 07:11:01 AM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Re: Boeing 767 speeds (was External antennas) gmcjetpilot@yahoo.com wrote: > > My point is the antenna does not care what size > plane it is on. Drag is drag. > > Drag is drag, and planes are planes; but the relative importance of a quantity of drag varies from plane to plane. A Cozy or Quickie can do 150mph to 200mph with 100Hp or less, because everything imaginable has been done to drop the drag. The drag of the antennae is no more than it would be on the same 90mph Pietenpol, but it is a much more significant portion of the entire airplane's drag. You can't take an antennae and say that it will have a specific speed penalty. You take the antennae and say how much power will be required to push it through the air at a specific speed. You have a power budget set by the engine. Any of that budget spent pushing antennaes through the air will not be available for pushing the airframe through the air. It is up to the builder to decide if spending a piece of that limited budget is worth the effort or degraded performance associated with not spending it. A 757 has a rather large power budget (compared to a Quickie). Sticking another antennae on is unlikely to even register, no matter what speed the airplane is going. I just isn't worth much effort to try to get it out of the airstream. Other configurations will differ. In my case, I know that I tend to be a heavy-handed klutz. No matter how hard I try, I know I'll break off an antennae every time I was the plane. My push to clean up my airframe has more to do with what I know will be a maintenance headache. ________________________________ Message 9 _____________________________________ Time: 07:35:18 AM PST US Subject: Re: AeroElectric-List: Re: Boeing 767 speeds (was External antennas) From: "Matt Prather" Think about it George, The antenna doesn't care what size airplane it's on, but different sized (flat plate drag) airplanes use differing amounts of thrust force to go the same speed. The thrust-drag balance determines speed. If you add 5 lbs of drag to an airplane that only makes 10lbs of thrust you change the cruise speed more than you would for an airplane that makes 500lbs of thrust to go the same speed. A 757 would care not about one more comm antenna when running 200kts (indicated), but a Lancair Legacy would notice it quite a bit. It's all about the relative drag vs. thrust balance. Cheers, Matt- Or is that Cheers Matt (to me)? > Mike: > > Not sure what your talking about, but I wrote or > should have wrote 460kt (true). > snip > My point is the antenna does not care what size > plane it is on. Drag is drag. > > Think about it, Mike > > Cheers George ATP/757/757/CE500 > ________________________________ Message 10 ____________________________________ Time: 07:45:55 AM PST US From: "Sam Hoskins" Subject: AeroElectric-List: Tefzel dielectric strength I am installing a strobe system with a 50 watt power supply from Nova. The system comes with a fairly heavy shielded 3-wire 18AWG cable that has 300V printed on the jacket. It does not appear to be tefzell coated. (I think it is mostly used in automotive applications, such as police and fire vehicles). Due to space constraints, I am unable the pass this thick cable through the openings in my wing. However, the shielded 3-wire 22AWG, from B&C will do the trick. What is my risk for using the 22AWG vs. the 18 AWG? Thanks Sam Hoskins Quickie Q-200 Murphysboro, IL ________________________________ Message 11 ____________________________________ Time: 10:37:26 AM PST US Subject: AeroElectric-List: Re: Tefzel dielectric strength From: "rampil" Sam, I would like to try to answer your question, but I am not sure I understand it. What does dielectric strength have to do it. Gauge size of wire determines voltage drop across its length Splicing in a short run of 22g will introduce 6 extra connections to reduce reliability (but for a strobe, realistically, who cares!) Is this cable, I presume the hot side of the strobe power, i.e., so the voltage is 500-1000 or so. Most insulation would be just fine. Dielectric puncture is not only dependent on the material constant be also the thickness -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=164258#164258 ________________________________ Message 12 ____________________________________ Time: 10:43:43 AM PST US From: Buckaroo Banzai Subject: Re: AeroElectric-List: RE: Why can't the tower hear me? You might try filing an ASRS. NASA will follow up with the FAA which might get a real technician out there to check the tower's radios and maybe any dead spots on the field. Greg "H. M. Haught Jr. " wrote: Cordiality wasn't in evidence at KOUN. I was told in no uncertain terms that it wasn't their fault that my radio was junk, but they would give me light signals to get me out. I tried to explain that I've had the radio worked on a number of times and their facility was the only place I was having any trouble, which was true at the time, and got the reply - "If you want light signals to get out, then tell me, but don't blame our equipment for your radio problems." I was on a telephone talking to them from the service office - wouldn't see me face to face. They see lots of high power stuff and cater to it - my old ratty looking Pacer was consider "junk". I took the light signals and the radio was working fine by the time I got to the end of the taxiway. Called up OK City immediately after leaving the pattern, had radio check and was told "five x five". Next time I go in, (I've got my hand held set up on an external antenna as a backup radio ), as soon as I power down, I'm going to call up tower for radio check on the Icom, and then do the same thing with the handheld on rubber ducky antenna. Next day, if I have problems, I'll try the rubber ducky antenna again, as using the external antenna on the hand held also resulted in unreadable transmissions. Just doesn't make sense that two different radios are having the same problem on the same day. M. Haught Greg Young wrote: -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of glen matejcek Sent: Thursday, February 14, 2008 7:39 AM Subject: AeroElectric-List: RE: Why can't the tower hear me? --> Hi All- Sounds like perhaps it's time for phone calls to the tower chief to make sure that he/she knows of the issue. If that gets no results, a letter to the regional office. Make sure to delineate all the steps you guys have taken to verify your own equipment ops. You can also call them to let them on the phone to coordinate a NORDO arrival. Just be sure to review the light gun signals. Also, remember to keep you Piet under 200 KIAS ;-) As an aside, I've a good friend who is a controller who has provided me with various insights. Included in those were that although they can't upgrade equipment, they do get new leather furniture. Makes one proud of the system. glen matejcek aerobubba@earthlink.net --------------------------------- ________________________________ Message 13 ____________________________________ Time: 10:52:25 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Tefzel dielectric strength At 09:42 AM 2/15/2008 -0600, you wrote: > >I am installing a strobe system with a 50 watt power supply from Nova. > The system comes with a fairly heavy shielded 3-wire 18AWG cable that >has 300V printed on the jacket. It does not appear to be tefzell >coated. (I think it is mostly used in automotive applications, such >as police and fire vehicles). > >Due to space constraints, I am unable the pass this thick cable >through the openings in my wing. However, the shielded 3-wire 22AWG, >from B&C will do the trick. > >What is my risk for using the 22AWG vs. the 18 AWG? The wire supplied with strobe kits is "Beldfoil" shielded trio of PVC insulated wires. This is a grand-fathered wire that was the best we could buy in 1967. Indeed, it's quite suitable for this task and should not be held a arm's length just because someone holds their nose over it. We did some calculations several years ago about the potential for reduced light output for having switched to 22AWG wires. It may have been so long ago that the discussion was pre-matronics . . . on Compuserve's AVSIG bulletin board! The consensus was that it would probably be difficult to measure the difference and you probably wouldn't "see" it. I think several folks tried it and reported satisfactory performance. It would be REALLY interesting to wire up a kit of strobes with the heads separated by a distance of 30 feet or so. Wire the right side with 18AWG and the other with 22AWG. Stand off about a mile and see if the observer can perceive any difference in the two flashes. If someone would loan me their kit of strobe goodies, I'll go do the experiment. I'll get a group of observers unaware of which side is small wire to tell me if they think one is noticeably different from the other. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 14 ____________________________________ Time: 11:45:41 AM PST US Subject: RE: AeroElectric-List: Tefzel dielectric strength From: "George, Neal E Capt MIL USAF 605TES/TSI" Bob - You can use mine, if they ever come back from Whelen. Neal If someone would loan me their kit of strobe goodies, I'll go do the experiment. I'll get a group of observers unaware of which side is small wire to tell me if they think one is noticeably different from the other. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 15 ____________________________________ Time: 12:55:24 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Tefzel dielectric strength At 01:42 PM 2/15/2008 -0600, you wrote: >605TES/TSI" > >Bob - > >You can use mine, if they ever come back from Whelen. > >Neal Okay, let's plan on it. It would be a short evening of fun work to do the experiment. I'm only a few miles from quiet country roads. No hurry . . .it's not going to be warm enough to be enjoyable for a few more weeks. Bob. . . ________________________________ Message 16 ____________________________________ Time: 03:24:58 PM PST US From: "Sam Hoskins" Subject: Re: AeroElectric-List: Tefzel dielectric strength That sounds like logical information. What about the 300V rating on the wire? Would the tefzel be similar? Here is the wire at B&C: http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?8X358218#s906-3-22 Sam On Feb 15, 2008 12:49 PM, Robert L. Nuckolls, III wrote: > > At 09:42 AM 2/15/2008 -0600, you wrote: > > > > >I am installing a strobe system with a 50 watt power supply from Nova. > > The system comes with a fairly heavy shielded 3-wire 18AWG cable that > >has 300V printed on the jacket. It does not appear to be tefzell > >coated. (I think it is mostly used in automotive applications, such > >as police and fire vehicles). > > > >Due to space constraints, I am unable the pass this thick cable > >through the openings in my wing. However, the shielded 3-wire 22AWG, > >from B&C will do the trick. > > > >What is my risk for using the 22AWG vs. the 18 AWG? > > The wire supplied with strobe kits is "Beldfoil" shielded > trio of PVC insulated wires. This is a grand-fathered wire > that was the best we could buy in 1967. Indeed, it's > quite suitable for this task and should not be held a > arm's length just because someone holds their nose over > it. > > We did some calculations several years ago about the > potential for reduced light output for having switched > to 22AWG wires. It may have been so long ago that the > discussion was pre-matronics . . . on Compuserve's > AVSIG bulletin board! > > The consensus was that it would probably be difficult > to measure the difference and you probably wouldn't "see" > it. > > I think several folks tried it and reported satisfactory > performance. It would be REALLY interesting to wire up > a kit of strobes with the heads separated by a distance > of 30 feet or so. Wire the right side with 18AWG and > the other with 22AWG. Stand off about a mile and see > if the observer can perceive any difference in the two > flashes. > > If someone would loan me their kit of strobe goodies, > I'll go do the experiment. I'll get a group of observers > unaware of which side is small wire to tell me if they > think one is noticeably different from the other. > > Bob . . . > > > ----------------------------------------) > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > ---------------------------------------- > > ________________________________ Message 17 ____________________________________ Time: 04:54:21 PM PST US Subject: AeroElectric-List: Re: Tefzel dielectric strength From: "rampil" OK Bob, Just remember that the human optical receiver system uses a log-sensitive scale, so even a doubling of intensity (double the number of photons) would be imperceptible. It would probably be easier to just measure the voltage spike on scope with the appropriate probe (admittedly not as much fun) -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=164332#164332 ________________________________ Message 18 ____________________________________ Time: 05:37:26 PM PST US From: "Robert Feldtman" Subject: Re: AeroElectric-List: RE: Why can't the tower hear me? Filing the NASA safety form is the BEST idea you can do. I'd also make a copy and send it to the closest Fed Communication Commision (FCC) field office. Just cause they are both fed gov't doesn't necessarily mean they will "cover" for each other. A bad transmitter is a bad transmitter. FCC might jack 'em up a notch or two - at least make them uncofmortable in the new leather chairs as they talk on their vaccuum tube jurassic radios. I'm not kiddin. bobf On 2/14/08, glen matejcek wrote: > > aerobubba@earthlink.net> > > Hi All- > > Sounds like perhaps it's time for phone calls to the tower chief to make > sure that he/she knows of the issue. If that gets no results, a letter to > the regional office. Make sure to delineate all the steps you guys have > taken to verify your own equipment ops. > > You can also call them to let them on the phone to coordinate a NORDO > arrival. Just be sure to review the light gun signals. Also, remember to > keep you Piet under 200 KIAS ;-) > > As an aside, I've a good friend who is a controller who has provided me > with various insights. Included in those were that although they can't > upgrade equipment, they do get new leather furniture. Makes one proud of > the system. > > glen matejcek > aerobubba@earthlink.net > > ________________________________ Message 19 ____________________________________ Time: 06:58:18 PM PST US From: Gilles Thesee Subject: Re: AeroElectric-List: Re: Boeing 767 speeds (was External antennas) Ernest Christley a crit : > Drag is drag, and planes are planes; but the relative importance of a > quantity of drag varies from plane to plane. > > A Cozy or Quickie can do 150mph to 200mph with 100Hp or less, because > everything imaginable has been done to drop the drag. The drag of the > antennae is no more than it would be on the same 90mph Pietenpol, but > it is a much more significant portion of the entire airplane's drag. > You can't take an antennae and say that it will have a specific speed > penalty. You take the antennae and say how much power will be > required to push it through the air at a specific speed. You have a > power budget set by the engine. Any of that budget spent pushing > antennaes through the air will not be available for pushing the > airframe through the air. It is up to the builder to decide if > spending a piece of that limited budget is worth the effort or > degraded performance associated with not spending it. Ernest, Matt, Couldn't agree more with you. I built a low drag airplane (MCR four seater), and indeed, hiding the antennas made quite a difference. The present cruise is 130-1135 kt on 100 hp with four on board at low altitude. We still have some cleaning to perform on the airframe. I remember having a long discussion with George on this issue some months ago. Best regards, -- Gilles http://contrails.free.fr ________________________________ Message 20 ____________________________________ Time: 07:10:52 PM PST US From: Gilles Thesee Subject: Re: AeroElectric-List: Re: Boeing 767 speeds (was External antennas) Gilles Thesee a crit : > The present cruise is 130-1135 kt 130-135 kt would more accurate ;-) Best regards, -- Gilles http://contrails.free.fr ________________________________ Message 21 ____________________________________ Time: 07:16:20 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Tefzel dielectric strength At 04:50 PM 2/15/2008 -0800, you wrote: > >OK Bob, > >Just remember that the human optical receiver system uses a log-sensitive >scale, so even a doubling of intensity (double the number of photons) >would be imperceptible. It would probably be easier to just measure the >voltage spike on scope with the appropriate probe (admittedly not as much >fun) But the 'real' question is not wether some techno-wienie can measure the differences on a visual attention-getting/warning system . . . but whether the guy expected to see and react to it can see a difference. I plan to do both. Bob . . . ________________________________ Message 22 ____________________________________ Time: 07:33:23 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Tefzel dielectric strength At 05:21 PM 2/15/2008 -0600, you wrote: > >That sounds like logical information. What about the 300V rating on >the wire? Would the tefzel be similar? Here is the wire at B&C: >http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?8X358218#s906-3-22 I don't recall any of the tefzel wires being rated at less than 600v. You can check through the listings for 22759 in ETFE in the catalog at: http://www.aeroelectric.com/Mfgr_Data/Wire/Standard_Wire_and_Cable/Std_Wire_Cable.pdf I suspect B&C's shielded trio is 22759/16 or 22759/34 both of which are 600v insulations. Bob . . . ________________________________ Message 23 ____________________________________ Time: 08:31:47 PM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Re: Boeing 767 speeds (was External antennas) Gilles Thesee wrote: > > > Gilles Thesee a crit : >> The present cruise is 130-1135 kt > > 130-135 kt would more accurate ;-) > > Best regards, Dang-it!! I was about to send a request for a set of plans. 8*) -- http://www.ronpaultimeline.com ------------------------------------------------------------------------------------- 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.