---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 04/23/10: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:08 AM - Re: Surface temperature sensor (Steve Thomas) 2. 06:33 AM - Re: Proper SWR meter (Robert L. Nuckolls, III) 3. 06:45 AM - Re: Proper SWR meter (earl_schroeder@juno.com) 4. 07:26 AM - Re: Future of general aviation (Ken Howell) 5. 09:41 AM - Re: Proper SWR meter (The Kuffels) 6. 01:47 PM - Re: Surface temperature sensor (rampil) 7. 02:11 PM - Re: Re: Surface temperature sensor (Dj Merrill) 8. 02:30 PM - Re: Re: Alternator field feed - fuse vs. fusible link (Robert L. Nuckolls, III) 9. 02:35 PM - Re: Proper SWR meter (Robert L. Nuckolls, III) 10. 07:41 PM - Re: Surface temperature sensor (J. Mcculley) 11. 11:33 PM - Big load on BAT BUS (jonlaury) 12. 11:39 PM - Re: Big load on BAT BUS (jonlaury) ________________________________ Message 1 _____________________________________ Time: 06:08:03 AM PST US Subject: Re: AeroElectric-List: Surface temperature sensor From: Steve Thomas Why off-list? I'm sure that many readers of the list would be interested. Please share with all of us! Steve Thomas ________________________________________________________________________ On Apr 22, 2010, at 1:19 PM, J. Mcculley wrote: > > I've been using a very inexpensive system with 18 sensor locations in my Wittman Tailwind for well over 500 hours and 7 years, with never a malfunction. It's based on inexpensive thermistors available from most electronics suppliers and feeds into the display head of an ordinary digital meat thermometer mounted on my instrument panel. It can handle up to 300 degree F which covers everything firewall-forward except engine cylinder EGT and CHT. > > If you want some part numbers and more details contact me off list at mcculleyja@starpower.net. > > Jim McCulley > =================================================================================== > > longg@pjm.com wrote: >> Q, >> Has anyone come across an example of a surface temperature sensor (generic)) that could be used on engine parts or perhaps the firewall and send a digital reading back to the panel? >> Example. I would like to measure the temperature on the surface of my oil filter/fuel pump and display that value on the panel. >> FYI I have stick-on thermometers that work great when performing engine checks on the ground but they are of little use in the air. >> Thanks, >> Glenn >> * * > > > > ________________________________ Message 2 _____________________________________ Time: 06:33:04 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Proper SWR meter At 11:46 PM 4/22/2010, you wrote: >Me: > ><< you must *transmit* power on the frequencies of interest, a >practice frowned upon by the FAA and the FCC unless you are >communicating with someone. >> > >Bob: > ><< Actually, the MFJ259 is an active emitter too but in the >milliwatt level. >> > >Absolutely true, but in this context all receivers are "active >emitters". For example, Canadian police use a special receiver to >detect the miniscule signal emitted by radar detectors to enforce >their ban on such devices. The point being made is the amount of >power needed to operate the old style SWR meters *will* cause >appreciable interference to other users while the MFJ259 and such >for all practical purposes will not. Sure, but that wasn't the point, the MFJ device one is looking for is not the "noise bridge antenna analyzer" or MFJ202. This network analyzer excited by a broadband noise source requires a receiver with a signal strength indicator tuned to the frequency of interest as part of the test equipment. Further their only noise bridge offering http://mfjenterprises.com/man/pdf/MFJ-202B.pdf is more of a system designer's instrument than a technicians test tool. Bob . . . ________________________________ Message 3 _____________________________________ Time: 06:45:13 AM PST US From: "earl_schroeder@juno.com" Subject: Re: AeroElectric-List: Proper SWR meter Bob wrote: Actually, the MFJ259 is an active emitter too but in the milliwatt level. But the best part is that it's ability to accurately display antenna and transmission line characteristics is quite good at 130 Mhz. I use to rent one to the OBAM aviation community but wear and tear outgo was higher than rental income. Bob . . . When you 'rented' the MFJ259, did you include a simplified instruction sheet? As a proud owner of a MFJ259, I would like a 'cook book' type instructions tailored to the OBAM aviation community. I would like to know all the theory etc but at this time do not have the time to invest in learning its complete capability and retaining it. I am interested but short on time. My Grandson currently has priority! I just want to know how to correctly connect it and read the SWR. Then some clues as to how to correct it if necessary. Then I would like to assist my EAA chapter folks in checking their installations. The MFJ259 sitting on the shelf isn't doing anyone an favors... (no, it isn't for sale at this time) Earl ________________________________ Message 4 _____________________________________ Time: 07:26:02 AM PST US From: "Ken Howell" Subject: RE: AeroElectric-List: Future of general aviation I agree with everything you said. There is one other factor to consider, affordability. It may have already been discussed. As an E3 in 1957, I could actually afford to take flying lessons. As a 25 year-old raising a family, I could afford to own and fly a Porterfield CP-65. Now with the cost of litigation and fuel, that is no longer the case for the majority of young people. Even with the new LSA rules, it's out of the reach of most. The lawyers have successfully killed the prospects of a continuing, vital General Aviation system in America, witness the recent 89 million dollar award against Lycoming, who are being made to pay for pilot error. The oil companies are contributing to its demise with their exhorbitant rates, insuring their continuing record profits each quarter. I'm still a capitalist and not overly pessimistic, but I have to say even though it was great while it lasted; RIP to GA in America. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Thursday, April 22, 2010 10:51 AM Subject: Re: AeroElectric-List: Future of general aviation --> >We all need to contribute to the continuance of this legacy by >supporting programs like Young Eagles, encouraging youth who express >interest in what we do, participating in information exchange forums >like this one, and never taking the privilege of flying for granted. I fear that the inoculation for indifference may be more complicated that enthusiastic offers of airplane rides. Our culture is slowly loosing its curiosity and excitement as to how and why things work. There's more interest in stepping up to the next revision of "Borg Wars" or seeking out the most outrageous roller coaster. The perpetual quest for transient pleasures is winning out over the joy of finding things out. Young Eagles is a fine idea but it's also a "process" enthusiastically endorsed by folks who think education is "flip switch A, insert tab C into slot D, watch video F, etc". Real teaching is a meeting of the minds, an exchange of concepts and a study of recipes for success crafted of simple-ideas. My grandson doesn't know what he's in for. We're going to cook, grow, build, design, cut metal, photoshop, autocad, cut wood, take things apart, put them back together and explore the simple-ideas that are discovered in the process. Exactly how he uses these experiences will ultimately be up to him. But without having peeked behind all those doors, how can he make well considered choices? Our contemporaries have, I suspect, not peeked behind many doors . . . their teachers (which includes EVERY adult interaction in their younger lives) have failed them. I have the signatures of more than 50 young eagles in my logbook . . . I'll bet not one of them has set foot back in an airplane . . . unless it was at the NEXT air show where free rides were offered again. That "privilege" thing is closely related to what doors have been peeked into. Present trends plotted into the future suggest that ANY privilege we now enjoy can disappear any time with the mere stroke of a pen in Washington. Bob . . . ________________________________ Message 5 _____________________________________ Time: 09:41:15 AM PST US From: "The Kuffels" Subject: Re: AeroElectric-List: Proper SWR meter << Sure, but that wasn't the point, the MFJ device one is looking for is not the "noise bridge antenna analyzer" or MFJ202 >> As usual, Bob is correct. I falsely "remembered" my MFJ HF/VHF SWR Analyzer Model MFJ-259B used noise bridge technology. Should have checked my instruction manual first and used the full, official name. The Model MFJ-259 Analyzer is what you will commonly find available from local ham radio operators/clubs. The original point remains, it is a much better tool to adjust aircraft antennas than the Lafayette style SWR meters. Tom Kuffel ________________________________ Message 6 _____________________________________ Time: 01:47:42 PM PST US Subject: AeroElectric-List: Re: Surface temperature sensor From: "rampil" Don't count on home and garden type thermometer systems to be especially accurate. They have no requirement to be calibrated or calibrateable. -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295453#295453 ________________________________ Message 7 _____________________________________ Time: 02:11:30 PM PST US Subject: Re: AeroElectric-List: Re: Surface temperature sensor From: Dj Merrill On 4/23/2010 4:45 PM, rampil wrote: > > Don't count on home and garden type thermometer systems to be > especially accurate. They have no requirement to be calibrated > or calibrateable. Easy enough to test - put the sensor in boiling water. If it is even remotely close to the right value, it is probably "good enough" for most of our purposes. Hard to argue with the price... :-) -Dj -- Dj Merrill - N1JOV Glastar Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/ Grumman Yankee Driver N9870L - http://deej.net/yankee/ ________________________________ Message 8 _____________________________________ Time: 02:30:33 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Alternator field feed - fuse vs. fusible link At 09:48 PM 4/22/2010, you wrote: > >Just to play the Devil's advocate: > >The breaker is part of an overvoltage protection circuit, not a >conventional B lead breaker prone to nuisance popping. Why would >anyone be resetting this breaker in flight after what is most likely >an overvoltage event? While we do our best to fine tune the dynamic response of all over-voltage protection systems, the designs are based on 99% probability dynamics. I.e., tailor your circuitry to these curves . . . http://www.aeroelectric.com/Reference_Docs/Mil-Specs/Mil-Std-704_excerpts.pdf . . . and you're good to go . . . MOST of the time. In 40+ years of designing and manufacturing various ov sensing systems, there have been a few instances where antagonists on the particular system were more aggressive that the 99% curves suggested. Hence, virtually every ov protection system has a pilot-resetable feature. Of course, like any breaker-trip, the most you want to tweak the tail of the tiger is one time before leaving it off and go to plan-B. Bob . . . ________________________________ Message 9 _____________________________________ Time: 02:35:00 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Proper SWR meter At 11:37 AM 4/23/2010, you wrote: ><< Sure, but that wasn't the point, the MFJ device one is > looking for is not the "noise bridge antenna analyzer" > or MFJ202 >> > >As usual, Bob is correct. I falsely "remembered" my MFJ HF/VHF SWR >Analyzer Model MFJ-259B used noise bridge technology. Should have >checked my instruction manual first and used the full, official >name. The Model MFJ-259 Analyzer is what you will commonly find >available from local ham radio operators/clubs. The original point >remains, it is a much better tool to adjust aircraft antennas than >the Lafayette style SWR meters. ABSOLUTELY!! I've owned three of them and it's the first tool I pick up when there are questions of feed line and/or antenna quality to be explored. I used to have a noise-bridge. It does perform as advertised and was VERY reasonably priced because the heavy lifting for test equipment was the companion receiver not supplied. I think I gave that one away many moons ago. Bob . . . ________________________________ Message 10 ____________________________________ Time: 07:41:21 PM PST US From: "J. Mcculley" Subject: Re: AeroElectric-List: Surface temperature sensor Sorry Steve and others...I just thought this subject might be of interest to so few that I should not take up bandwith that those not interested would have to deal with. But, here it is: This is a very accurate system that I tested with a laboratory quality temperature meter and found the accuracy of all my sensors to be two degrees F. It may not be very sophisticated, but it is super-inexpensive and has never malfunctioned. I use it on every flight to assure myself that no changes suddenly occur that could indicate a malfunction. Mine is about a $15 to $25 system that I've operated now for over seven years and upwards of 600 flight hours on it's original internal watch-size battery. The sensors are standard mini glass-encapsulated thermistors available from most electronic supply sources. I used Digi-Key # KC013-ND, 100k ohm units. For those sensors measuring metal surface temperatures (cylinder bases, starter, mags, boost pump, alternator, etc.) the sensors are attached to the surfaces with heat sink grease, and held in place mechanically and/or with a coating of the red 600 degree RTV, then insulated from surrounding radiation with fireman's suit material. To assure firm contact with the surface until the RTV sets requires some simple tricks I wont cover unless you desire later. Those sensors that measure airflow temperatures are mechanically supported in various ways depending upon the surrounding environment, and are then shielded from nearby heat radiation, using standoff shields. The display is a panel mounted single LCD with a compact surface mount IC unit that I adapted from a meat thermometer with a range up to 300F. The head of the meat thermometer becomes the panel mounted digital display after cutting off the long stem, but retaining the internal pair of wires to the display head. The individual sensor locations are selected for readout through a rotary switch on the panel. The delay in the presentation from one sensor selection to the next is less than one second and my poor-man's data recording system is via my hot mike through the intercom to a voice recorder. In this current era of exotic digital commercial boxes for anything a person desires, my "keep-it-simple and build-in-lightness mentality" may not be the answer for others, but I don't mind post-flight manually inputting the data from my recorder into a spreadsheet for further massaging if needed. The installation of the thermistors is simpler and much less expensive than thermocouples and since the thermistors operate in a very high-impedence circuit the wiring need not be any larger size than needed to assure mechanical robustness. I used 22 gauge wire and joined all the ground return wires together to pass through the firewall as a single lead, so the wire bundle becomes very small aft of the firewall. Also, because of the very high impedence of the circuitry, there is no sensitivity to length of individual sensor wires between thermistor and display for any possible location within a general aviation installation. Good quality soldering technique is very adequate for connections, as are properly-crimped-on terminals, if desired. ======================================================================= Steve Thomas wrote: > > Why off-list? I'm sure that many readers of the list would be interested. > Please share with all of us! > > > Steve Thomas > ________________________________________________________________________ > > > > > On Apr 22, 2010, at 1:19 PM, J. Mcculley wrote: > >> I've been using a very inexpensive system with 18 sensor locations in my >> Wittman Tailwind for well over 500 hours and 7 years, with never a >> malfunction. It's based on inexpensive thermistors available from most >> electronics suppliers and feeds into the display head of an ordinary >> digital meat thermometer mounted on my instrument panel. It can handle >> up to 300 degree F which covers everything firewall-forward except engine >> cylinder EGT and CHT. >> >> If you want some part numbers and more details contact me off list at >> mcculleyja@starpower.net. >> >> Jim McCulley >> ========================================================================= >> >> longg@pjm.com wrote: >>> Q, >>> Has anyone come across an example of a surface temperature sensor (generic)) >>> that could be used on engine parts or perhaps the firewall and send a digital >>> reading back to the panel? >>> Example. I would like to measure the temperature on the surface of my >>> oil filter/fuel pump and display that value on the panel. >>> FYI I have stick-on thermometers that work great when performing >>> engine checks on the ground but they are of little use in the air. >>> Thanks, >>> Glenn >>> * * > > > > > > ________________________________ Message 11 ____________________________________ Time: 11:33:45 PM PST US Subject: AeroElectric-List: Big load on BAT BUS From: "jonlaury" In an attempt to keep redundant critical items from the same bus, I have placed the fuse (10-15 amp) for my EFI injectors on the Bat Bus. However, this violates BoB N's limit of Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295529#295529 ________________________________ Message 12 ____________________________________ Time: 11:39:50 PM PST US Subject: AeroElectric-List: Re: Big load on BAT BUS From: "jonlaury" Never mind about the SS sleeve question. It will only be a 10 gauge wire and I will 18 ga fuselink it at the battery. J Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295530#295530 ------------------------------------------------------------------------------------- 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.