---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 08/30/09: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:44 AM - Balun for VOR antenna (Gilles Thesee) 2. 05:39 AM - Transponder Re-Check? () 3. 06:37 AM - Re: Groundblock Tube/Fabric Airplane (special4) 4. 07:50 AM - Re: Re: Transmit noise (Ian) 5. 09:07 AM - Re: Balun for VOR antenna (Robert L. Nuckolls, III) 6. 09:19 AM - Re: Re: Transmit noise (Robert L. Nuckolls, III) 7. 12:44 PM - Re: Balun for VOR antenna (Gilles Thesee) 8. 05:33 PM - Re: Transponder Re-Check? (al38kit) 9. 06:13 PM - Re: Re: Transponder Re-Check? (Don Curry) 10. 06:20 PM - Re: Re: Transponder Re-Check? (Dj Merrill) 11. 06:34 PM - Re: Transponder Re-Check? (al38kit) 12. 07:11 PM - Sensor wires with ignition leads (Bob Barrow) 13. 08:43 PM - Re: CHT probes (Doug Baleshta) 14. 10:54 PM - Re: Re: CHT probes (David M) ________________________________ Message 1 _____________________________________ Time: 01:44:42 AM PST US From: Gilles Thesee Subject: AeroElectric-List: Balun for VOR antenna Bob and all, While helping a friend wiring his airplane, I stumbled on the instruction leaflet for his RA-Miller VOR antenna. It calls for a specific built-in balun coax. My intention was to follow the instructions in http://www.aeroelectric.com/articles/BALUN/Balun_Fabrication.html, but the coax already installed and bundled in the fuselage is RG 58. To avoid crawling into the fuselage and doing everything again, is it doable to keep the RG 58, and WHEN and IF a balun is required, to add a portion of RG 400 with the balun via a pair of BNC connectors ? Thanks in advance, Best regards, -- Gilles http://contrails.free.fr ________________________________ Message 2 _____________________________________ Time: 05:39:03 AM PST US From: Subject: AeroElectric-List: Transponder Re-Check? 8/30/2009 Don Wrote "Will I need another transponder/encoder cert IAW 91.413?" Here is what 91.413 says: "91.413 ATC transponder tests and inspections. (a) No persons may use an ATC transponder that is specified in 91.215(a), 121.345(c), or 135.143(c) of this chapter unless, within the preceding 24 calendar months, the ATC transponder has been tested and inspected and found to comply with appendix F of part 43 of this chapter; and (b) Following any installation or maintenance on an ATC transponder where data correspondence error could be introduced, the integrated system has been tested, inspected, and found to comply with paragraph (c), appendix E, of part 43 of this chapter." It would appear that if you could satisfy yourself in some manner (preferably documented) that "data correspondence error" could not be introduced either by the repair or your subsequent reinstallation then no Appendix E recheck would be required. First flights after reinstallation should include some airborne check of the system with ATC. Why not ask the people who just did your check what their opinion is -- realizing that it may not be entirely unbiased. 'OC' Says: "The best investment we can make is the effort to gather and understand knowledge." ============================================ Time: 07:51:42 AM PST US From: "Don Curry" Subject: Avionics-List: Transponder Re-Check? I just had my biennial transponder/encoder certification (IAW FAR 91.413) done. The system passed and log book was signed off. On the very next flight, the transponder acted up. I had it pulled and sent off for repairs and it is due back Monday with a fresh 8130. Will I need another transponder/encoder cert IAW 91.413? Don ________________________________ Message 3 _____________________________________ Time: 06:37:14 AM PST US Subject: AeroElectric-List: Re: Groundblock Tube/Fabric Airplane From: "special4" Thanks Bob, thanks Rodney, I will do the tests as you are recommending, and try to isolate the noise. Re headsets; I have 2 headsets, one is a PNR and the 2nd one is a ANR. With the ANR headset I could hear the rpm changes , but after I have installed the sparkplugwire shielding that noise is gone. Peter -------- Sportsflyer Read this topic online here: http://forums.matronics.com/viewtopic.php?p=260461#260461 ________________________________ Message 4 _____________________________________ Time: 07:50:31 AM PST US Subject: Re: AeroElectric-List: Re: Transmit noise From: Ian I'd like to offer two small ideas since they both seem to make a big difference in my aircraft: 1. The headset manufacturer says put the mike 1/8" from your mouth. That's pretty close, and the further away it is the more other noises can be heard. 2. I noticed most of my transmit noise went away if I unplugged the second headset, or switched the intercom to "isolate" even though the second PTT wasn't pushed. Not sure why that is, or whether it was just noise in my headset that wasn't actually being transmitted. Ian Brown Bromont Quebec, RV-9A ________________________________ Message 5 _____________________________________ Time: 09:07:44 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Balun for VOR antenna At 03:32 AM 8/30/2009, you wrote: > > >Bob and all, > >While helping a friend wiring his airplane, I stumbled on the >instruction leaflet for his RA-Miller VOR antenna. It calls for a >specific built-in balun coax. >My intention was to follow the instructions in >http://www.aeroelectric.com/articles/BALUN/Balun_Fabrication.html, >but the coax already installed and bundled in the fuselage is RG 58. >To avoid crawling into the fuselage and doing everything again, is >it doable to keep the RG 58, and WHEN and IF a balun is required, to >add a portion of RG 400 with the balun via a pair of BNC connectors ? It is never "required". Thousands of airplanes were built in the 50's and 60's where the coax feedline to a VOR antenna "whiskers" were simply attached to the two antenna elements: center conductor to on, shield to the other. This is depicted on 'Connection drawings in the chapter on antennas. If I interpret the words describing the RA Miller AV12 antenna at: http://www.aircraftspruce.com/catalog/avpages/av12L_ant.php it says that the balun is "integral to the coax supplied". I don't see how this is done in the data supplied. However, you're not on shaky ground to simply install per manufacturer's instructions using cable supplied. While not necessarily the best we know how to do, its performance will be entirely satisfactory. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 6 _____________________________________ Time: 09:19:18 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Transmit noise At 09:45 AM 8/30/2009, you wrote: >I'd like to offer two small ideas since they both seem to make a big >difference in my aircraft: > >1. The headset manufacturer says put the mike 1/8" from your >mouth. That's pretty close, and the further away it is the more >other noises can be heard. Sure. This is typical of any noise canceling mic. The term noise cancelling is mis-leading. Microphones cannot differentiate between "noise" and "good stuff." Depending on their quality, they may do a fair job of differentiating between near-field sounds (your voice) and far-field sounds (noise). The further your voice moves away from the microphone, the less it looks like good stuff and the more it looks like noise. >2. I noticed most of my transmit noise went away if I unplugged the >second headset, or switched the intercom to "isolate" even though >the second PTT wasn't pushed. Not sure why that is, or whether it >was just noise in my headset that wasn't actually being transmitted. Aha! TWO microphones that are tied together without benefit of separate voice-operated switching. These systems suffer full-time bombardment of TWICE the noise when only one person is talking. This causes you to tighten squelch controls to silence the extra noise and requires that voices be louder (or microphone half way down your throat) in order that the tighter squelch be accommodated. I'm pretty sure that 90% of your problem arises from the combination of headsets and your audio system's handling of microphone signals. It is unlikely that you can achieve much better results without replacing the intercom, headsets or both. You're not alone in believing that stuff designed for "aircraft" is suited for cockpits with essentially open-air noise levels. I'm thinking that intercoms designed for mounting in helmets of motor cycles may be better designed for this task. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 7 _____________________________________ Time: 12:44:13 PM PST US From: Gilles Thesee Subject: Re: AeroElectric-List: Balun for VOR antenna Thank you for your quick and comprehensive answer. > It is never "required". Thousands of airplanes > were built in the 50's and 60's where the coax > feedline to a VOR antenna "whiskers" were simply > attached to the two antenna elements: center > conductor to on, shield to the other. This is what I did with RG 58. > > However, you're not on shaky ground to simply install > per manufacturer's instructions using cable supplied. The problem is, the antenna was purchased with no cable. Thanks again, Best regards, -- Gilles http://contrails.free.fr ________________________________ Message 8 _____________________________________ Time: 05:33:18 PM PST US Subject: AeroElectric-List: Re: Transponder Re-Check? From: "al38kit" Here's a realistic idea. When your transponder comes back, put it in and forget about the paperwork. Al Read this topic online here: http://forums.matronics.com/viewtopic.php?p=260540#260540 ________________________________ Message 9 _____________________________________ Time: 06:13:24 PM PST US From: Don Curry Subject: RE: AeroElectric-List: Re: Transponder Re-Check? I'm fighting that very temptation. However, all too often if a person will compromise once, s/he'll do it again. And I don't want to be that person. As near as I can tell, it's best just to play by the rules. After all, it's a hobby, right? Don > -----Original Message----- > From: alfranken@msn.com > Sent: Sun, 30 Aug 2009 17:31:05 -0700 > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: Re: Transponder Re-Check? > > > Here's a realistic idea. > > When your transponder comes back, put it in and forget about the > paperwork. > > Al > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=260540#260540 > > > > > > > ________________________________ Message 10 ____________________________________ Time: 06:20:47 PM PST US Subject: Re: AeroElectric-List: Re: Transponder Re-Check? From: Dj Merrill On 8/30/2009 8:56 PM, Don Curry wrote: > After all, it's a hobby, right? Er, no, its an addiction actually... ;-) -Dj ________________________________ Message 11 ____________________________________ Time: 06:34:06 PM PST US Subject: AeroElectric-List: Re: Transponder Re-Check? From: "al38kit" If it's a hobby, then I would expect the answer should be really easy. Put it back in and forget about it. If it's in a plane you're flying for a living, and could potentially lose your shirt over a lawsuit, then it's a different situation. If you're so worried about not following the rules once (how old are you?) and then thinking you'll be addicted...I don't know what to tell you...javascript:emoticon('[Twisted Evil]') [quote="don.curry(at)inbox.com"]I'm fighting that very temptation. However, all too often if a person will compromise once, s/he'll do it again. And I don't want to be that person. As near as I can tell, it's best just to play by the rules. After all, it's a hobby, right? Don > -- [Twisted Evil] [Twisted Evil] [Twisted Evil] Read this topic online here: http://forums.matronics.com/viewtopic.php?p=260557#260557 ________________________________ Message 12 ____________________________________ Time: 07:11:44 PM PST US From: Bob Barrow Subject: AeroElectric-List: Sensor wires with ignition leads I've seen quite a few Experimental aircraft (and some certificated aircraft ) with the EGT and CHT sensor wires bundled with the lower ignition leads o n Lycoming engines. The usual protocol is to attach the lower ignition leads to the cylinder he ads by means of a clamp attached at the lower rocker cover screw. The EGT a nd CHT sensor wires are then run through the same clamp. Is this a kosher practice. It's certainly convenient....but are there any d ownsides to bundling these sensor wires with ignition leads. Regards Bob Barrow _________________________________________________________________ View photos of singles in your area Click Here ________________________________ Message 13 ____________________________________ Time: 08:43:59 PM PST US From: "Doug Baleshta" Subject: AeroElectric-List: Re: CHT probes I don't think I've seen this anywhere on the list, but is there a difference between a type K thermocouple ring style (sits under the sparkplug between the sparkplug and the head) vs the straight style that screws into the head? And, I believe Bob (or someone) mentioned that standard aircraft wire can connect to the thermocouple wires if they are not long enough, provided the lengths are identical, is that correct? thanks Doug ________________________________ Message 14 ____________________________________ Time: 10:54:14 PM PST US From: David M Subject: Re: AeroElectric-List: Re: CHT probes For TC's, Greg, it is not recommended. The unit depends upon an exact measurement between two certain wires (dependent upon TC type.) David M... Doug Baleshta wrote: > > I don't think I've seen this anywhere on the list, but is there a difference between a type K thermocouple ring style (sits under the sparkplug between the sparkplug and the head) vs the straight style that screws into the head? And, I believe Bob (or someone) mentioned that standard aircraft wire can connect to the thermocouple wires if they are not long enough, provided the lengths are identical, is that correct? > > thanks > Doug > > > > ------------------------------------------------------------------------ > > > Checked by AVG - www.avg.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.