Madhatter Posted October 7, 2015 Report Share Posted October 7, 2015 I was referring to ac voltage used in some avionics circuitry, and through a wire, can induce voltage into other wires. You would have to look at schematics of the installed equipement to determine this. This is not exclusive to large aircraft. Shielding is the easiest way to solve this if needed. I have noticed that there are no shielded wires in my ct, including serial wires of which I have changed. I will find and correct this problem in my ct when I am finished with another aircraft restoration project. I am only bringing up this anomaly because it occurs in my ct, I can't speak for any other ct Link to comment Share on other sites More sharing options...
Anticept Posted October 7, 2015 Report Share Posted October 7, 2015 I was referring to ac voltage used in some avionics circuitry, and through a wire, can induce voltage into other wires. You would have to look at schematics of the installed equipement to determine this. This is not exclusive to large aircraft. Shielding is the easiest way to solve this if needed. I have noticed that there are no shielded wires in my ct, including serial wires of which I have changed. I will find and correct this problem in my ct when I am finished with another aircraft restoration project. I am only bringing up this anomaly because it occurs in my ct, I can't speak for any other ct The only AC in avionics bundles would be in radio antenna coax cables, and they should come shielded and routed separately from wire bundles anyways. The circuits inside of the avionics should also be heavily shielded. There's such an incredibly tiny amount of AC on those wires when not transmitting that it takes significant amplification before it's usable. It's the risk of other devices interfering with those antenna coax that they are shielded. Everything will use switched/attenuated DC. Switching is simpler, while attenuating is easier for high-speed communications. Using AC as a carrier wave across copper would make the electronics unnecessarily and pointlessly complex. I'm not saying you're wrong in your induction theory, I'm just saying you're not going to find AC (by design) in a CT, and pretty much any small aircraft, or even medium aircraft, for that matter. Fluctuating DC can induce electrical current just as well as AC, all that is needed is a changing current (and thus, the electrical flux changes, which will cross over nearby wires, inducing current). Systems that don't transmit carrier waves should only need shielding, as you said. But, as an additional point: those systems which are very sensitive to interference, cross-talk, or induction should be using twisted pairs (preferably with shielding if they are super sensitive). EDIT: Now that I think about it, mic and headset jack leads are probably AC, but these should be in a shielded, possibly twisted pair, anyways. If not, they can feed interference into the intercom and radios. If you guys can think of anything else, feel free to point them out! Link to comment Share on other sites More sharing options...
Madhatter Posted October 7, 2015 Report Share Posted October 7, 2015 I am only referencing my observation on my aircraft and what I have found in my many years of dealing with this. You do what you want with this, I am not interested in big debates, egos or gurus. From now on anything I feel is pertinent I will mention to Roger and he can disposition it. Link to comment Share on other sites More sharing options...
Anticept Posted October 7, 2015 Report Share Posted October 7, 2015 Look, I feel it is important to point out AC/DC because you won't have much luck finding voltage using the wrong setting on a voltmeter. Someone working on an experimental could damage their systems if they don't use the right settings and make a decision based on inaccurate data. Maybe I'm being too pedantic, but my google searches are still turning up not-quite-correct information when I am trying to research a complicated subject. I have made bad decisions due to inaccuracies (nothing serious), which is why I make an effort to mention if I am simplifying a subject that I am explaining, or pointing out inaccuracies in other's posts. It's not an attack on you, your character, or necessarily your methods, it is an effort to try and keep accurate information presented for "drive by readers" who are trying to research. Link to comment Share on other sites More sharing options...
Madhatter Posted October 7, 2015 Report Share Posted October 7, 2015 I am done with this forum Link to comment Share on other sites More sharing options...
Anticept Posted October 7, 2015 Report Share Posted October 7, 2015 Best of luck, sorry that I got you upset. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted October 7, 2015 Report Share Posted October 7, 2015 I am done with this forum Wow, that escalated quickly. Link to comment Share on other sites More sharing options...
Anticept Posted October 7, 2015 Report Share Posted October 7, 2015 Sorry; I'm an engineer at heart and have a big thing about accuracy, especially when posted in a public place. I also strive for healthy debate, not for the purposes of being right, but for the fact that both individuals and onlookers can gain so much from hearing competing views. It's one of the most effective ways humankind has invented for hammering out common ground in science and finding truth in discoveries and engineering, as long as people set aside their PRIDE. I can come across sometimes like sandpaper on skin, but the information I try to provide could prove valuable to someone someday. I'm sorry that my social side is dry and cold, but it's in my personality; i value factual accuracy above all else, and it does rub people the wrong way sometimes... Still though, I hope at least the info that I provide is helpful. In the case of madhatter's post, he is right about induction, it's just that in our aircraft it will more than likely be caused by fluctuating DC. In copper communications, this is called crosstalk. As a sidenote, in radios, though, it can also be caused by radio frequency interference, such as from poorly sielded LED switched mode power supplies, or from a poorly shielded ignition system. Link to comment Share on other sites More sharing options...
Tom Baker Posted October 7, 2015 Report Share Posted October 7, 2015 Anticept needs a vacation from this site. I really don't think he needs a vacation from the site. Now there was this other guy who was banned just before you joined. He could be quite disruptive to the forum at times. He was banned once or twice, but kept signing back up under a different user name. It's people like that who need a vacation from this site. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted October 7, 2015 Report Share Posted October 7, 2015 Corey says what he means, and none of his comments are particularly inflammatory, nor are they personal attacks. If what he says wraps you around your own axle, then maybe you are a little too sensitive. When did spirited debate become a cause for bans, and when did we become so thin-skinned that such a thing would even occur to us? Link to comment Share on other sites More sharing options...
gbigs Posted October 7, 2015 Report Share Posted October 7, 2015 Corey says what he means, and none of his comments are particularly inflammatory, nor are they personal attacks. If what he says wraps you around your own axle, then maybe you are a little too sensitive. When did spirited debate become a cause for bans, and when did we become so thin-skinned that such a thing would even occur to us? Anticept, on 06 Oct 2015 - 6:52 PM, said: False equivalence. You're kidding, right? Link to comment Share on other sites More sharing options...
FlyingMonkey Posted October 7, 2015 Report Share Posted October 7, 2015 You're kidding, right? Nope. If you are offended by strong opinions using salty language, the Internet is not really for you. This is not kindergarten. Link to comment Share on other sites More sharing options...
AZAV8OR Posted October 7, 2015 Report Share Posted October 7, 2015 Corey says what he means, and none of his comments are particularly inflammatory, nor are they personal attacks. If what he says wraps you around your own axle, then maybe you are a little too sensitive. When did spirited debate become a cause for bans, and when did we become so thin-skinned that such a thing would even occur to us? Totally agree!! Link to comment Share on other sites More sharing options...
AZAV8OR Posted October 7, 2015 Report Share Posted October 7, 2015 "Now, about that engine oil . . . . where were we?" Yes, let's get back on track: I'm waiting for my oil cooler to come back from getting hot flushed. On their first pass, they got the flow up from 7GPH to 9GPH. I've not yet heard if it got any better after multiple passes. I'm hoping that the 22% flow increase will make the difference. They are sending me the debris that came out on the first pass. I'm sending it to Blackstone for analysis, as I'm concerned about its source in an engine that's only 165 hours old. More later. Link to comment Share on other sites More sharing options...
207WF Posted October 9, 2015 Report Share Posted October 9, 2015 About those oil temps again: Yes, I have put in springs, but no, I have not flushed beyond what Roger and I did in his shop. I have had this since the bird was 6 months old, but I suppose that does not mean that a good flush won't help! WF Link to comment Share on other sites More sharing options...
Roger Lee Posted October 9, 2015 Report Share Posted October 9, 2015 Hi Wayne, kevin flushed his in the shop too, but they still got crud out when he didn't get anything. Kevin's cooler is on the way back and they sent the crud for analysis with it. He got a 25% increase in flow. It will be interesting to see how this plays out once he takes his test flight next week. If his oil temps drop then I would pull my cooler off and send it to the Hot Flush shop. Link to comment Share on other sites More sharing options...
207WF Posted October 9, 2015 Report Share Posted October 9, 2015 I will be listening for the results! WF Link to comment Share on other sites More sharing options...
Ed Cesnalis Posted October 9, 2015 Report Share Posted October 9, 2015 Any yellow cheese? Link to comment Share on other sites More sharing options...
AZAV8OR Posted October 9, 2015 Report Share Posted October 9, 2015 Any yellow cheese? No. Will report back when the analysis comes back from Blackstone. Link to comment Share on other sites More sharing options...
AZAV8OR Posted October 9, 2015 Report Share Posted October 9, 2015 Ed, What was your oil flow before and what was it after the hot flush? Link to comment Share on other sites More sharing options...
Ed Cesnalis Posted October 9, 2015 Report Share Posted October 9, 2015 I don't think hot flush provided before and after flow rates to me. Link to comment Share on other sites More sharing options...
sandpiper Posted October 12, 2015 Report Share Posted October 12, 2015 About those oil temps again: Yes, I have put in springs, but no, I have not flushed beyond what Roger and I did in his shop. I have had this since the bird was 6 months old, but I suppose that does not mean that a good flush won't help! WF Same here. Had no problem the summer of 2007 which is the first summer. Plane was new. Plus it still had the factory set prop which maxed out at 5300 RPM. Problems started during summer #2 and have continued. The only change I made after summer #1 was flatten the prop to 5600 RPM. That should make it run cooler, right? Instead, climbing from 200 MSL to 5000 MSL with full throttle and 85-90 KIAS and 78 on the OAT, the oil temp will be mid yellow and climbing. Temp inversion that day, OAT on ground was 67F which increased to 78F at 5000 MSL. In order to go higher I had to level out and run at 5000 RPM to get the temp down so I could continue the climb. Running at 5200 RPM would not let the engine cool but did stop the upward trend. Maybe a hot flush is in order? Link to comment Share on other sites More sharing options...
AZAV8OR Posted October 13, 2015 Report Share Posted October 13, 2015 John, My oil cooler just got back from HotFlush. It will be installed tomorrow, test flight Wednesday AM. Stay tuned. Link to comment Share on other sites More sharing options...
IrishAl Posted October 13, 2015 Report Share Posted October 13, 2015 Anticept is an excellent contributor to this forum - he's thorough, conscientious and willing to learn from others. Just wanted to mark my appreciation for all I've learned from him. Link to comment Share on other sites More sharing options...
Anticept Posted October 13, 2015 Report Share Posted October 13, 2015 Anticept is an excellent contributor to this forum - he's thorough, conscientious and willing to learn from others. Just wanted to mark my appreciation for all I've learned from him. Thanks for the kind words, but don't forget to include everyone else . I think everyone here has contributed at least a thing or two, especially roger whom I had actually learned a lot from, and FastEddieB who has presented a lot of flying safety advice and helped me re-examine my thought process more than once. Did you post this in the wrong thread, by the way? Link to comment Share on other sites More sharing options...
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