---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 02/08/21: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:49 AM - Molex vs bus bar (Daryl Thompson) 2. 08:22 AM - Re: Molex vs bus bar (Charlie England) 3. 08:58 AM - Re: Molex vs bus bar (Daryl Thompson) 4. 10:00 AM - Re: Molex vs bus bar (Charlie England) 5. 10:19 AM - Re: Molex vs bus bar (Daryl Thompson) 6. 11:29 AM - Re: EFIS Erratic Temp Readings () 7. 04:21 PM - Re: Molex vs bus bar (user9253) 8. 05:04 PM - Antenna Grounding (Eric Page) 9. 07:53 PM - Re: Antenna Grounding (user9253) 10. 07:57 PM - Re: Antenna Grounding (user9253) ________________________________ Message 1 _____________________________________ Time: 06:49:25 AM PST US From: Daryl Thompson Subject: AeroElectric-List: Molex vs bus bar Need some thoughts from you guys. I am installing 8 Mitchell products cluster gauges in a 1978 PA32-300 (fuel qty, oil press, oil tem, etc). I am wondering if there are any disadvantages to using a molex 8 pin connector with one side having the 8 power wires connected to it and the other side with the single 20 AWG power wire to one pin location and then use jumping wires to connect in series the other remaining pins so as to power the entire set of 8 gauge clusters. Each cluster draws 1/10th amp and 20 AWG wire is attached to the existing 5A Inst Gauge C/B. The other alternative would be to use a bus bar but I am very limited in locating a good place to attach a bar. Could I also do the same for the grounding wires, i.e. 8 ground wires to one side of the molex connector and other side with a single grounding wire with jumped pins. The single ground wire (size?) would be grounded to the frame. The entire installation will be receiving a 337 field approval. Thoughts? ________________________________ Message 2 _____________________________________ Time: 08:22:27 AM PST US Subject: Re: AeroElectric-List: Molex vs bus bar From: Charlie England On 2/8/2021 8:48 AM, Daryl Thompson wrote: > Need some thoughts from you guys. I am installing 8 Mitchell products > cluster gauges in a 1978PA32-300 (fuel qty, oil press, oil tem, etc). > I am wondering if there are any disadvantages to using a molex 8 pin > connector with one side having the 8 power wires connected to it and > the other side with the single 20 AWG power wire to one pin location > and then use jumping wires to connect in series the other > remainingpins so as to power the entire set of 8 gauge clusters. Each > cluster draws 1/10th amp and 20 AWG wire is attached to the existing > 5A Inst Gauge C/B. The other alternative would be to use a bus bar > but I am very limited in locating a good place to attach a bar. Could > I also do the same for the grounding wires, i.e. 8 ground wires to one > side of the molex connector and other side with a single grounding > wire with jumped pins. The single ground wire (size?) would be > grounded to the frame. The entire installation will be receiving a 337 > field approval. Thoughts? The architecture sounds reasonable to me, but my personal choice of hardware would not be molex. I was an electronics tech in several past lives, and saw a *lot* of reliability issues with them, in a lot of different environments. In addition, jumping that many pins would be as big a pain as just jumping from instrument to instrument in the 'traditional' fashion of wiring instruments. My choice of hardware would be Dsub. The airframe side of the connector could be a molded solder cup style, allowing you to bridge an entire line of pins with a single bared wire for B+, and the same on the other line for ground. A 25 pin connector would likely take less real estate than a 16 pin molex. The instrument side of the connector could be the removable pin type of connector, making it easy to add additional power wires for each instrument. Similar idea to the 'panel ground bus' detailed in the AEC drawings, but with one row being the supply instead of ground. FWIW, Charlie -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 3 _____________________________________ Time: 08:58:22 AM PST US From: Daryl Thompson Subject: Re: AeroElectric-List: Molex vs bus bar Awesome idea! Thank you sir! Any recommendations on the best place to buy the d subs? On Mon, Feb 8, 2021 at 11:27 AM Charlie England wrote: > ceengland7@gmail.com> > > On 2/8/2021 8:48 AM, Daryl Thompson wrote: > > Need some thoughts from you guys. I am installing 8 Mitchell products > > cluster gauges in a 1978 PA32-300 (fuel qty, oil press, oil tem, etc). > > I am wondering if there are any disadvantages to using a molex 8 pin > > connector with one side having the 8 power wires connected to it and > > the other side with the single 20 AWG power wire to one pin location > > and then use jumping wires to connect in series the other > > remaining pins so as to power the entire set of 8 gauge clusters. Each > > cluster draws 1/10th amp and 20 AWG wire is attached to the existing > > 5A Inst Gauge C/B. The other alternative would be to use a bus bar > > but I am very limited in locating a good place to attach a bar. Could > > I also do the same for the grounding wires, i.e. 8 ground wires to one > > side of the molex connector and other side with a single grounding > > wire with jumped pins. The single ground wire (size?) would be > > grounded to the frame. The entire installation will be receiving a 337 > > field approval. Thoughts? > The architecture sounds reasonable to me, but my personal choice of > hardware would not be molex. I was an electronics tech in several past > lives, and saw a *lot* of reliability issues with them, in a lot of > different environments. In addition, jumping that many pins would be as > big a pain as just jumping from instrument to instrument in the > 'traditional' fashion of wiring instruments. > > My choice of hardware would be Dsub. The airframe side of the connector > could be a molded solder cup style, allowing you to bridge an entire > line of pins with a single bared wire for B+, and the same on the other > line for ground. A 25 pin connector would likely take less real estate > than a 16 pin molex. The instrument side of the connector could be the > removable pin type of connector, making it easy to add additional power > wires for each instrument. Similar idea to the 'panel ground bus' > detailed in the AEC drawings, but with one row being the supply instead > of ground. > > FWIW, > > Charlie > > -- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > ________________________________ Message 4 _____________________________________ Time: 10:00:15 AM PST US From: Charlie England Subject: Re: AeroElectric-List: Molex vs bus bar They're sold by just about every vendor that handles electronic components, so it's hard to recommend just one. For the individual crimp pin type, B&C would be a great choice. https://bandc.com/product-category/electrical-supplies/d-sub-audio-connectors/ For solder style (and crimp, as well), just about any of the 'usual suspects'. Newark, Mouser, Digi-Key, Allied, etc. The highest quality individual pins are like the ones B&C sells; known as 'machined pins', that have gold plated contact surfaces. Some (not all) of the solder type connectors will have gold plated contact surfaces, as well. Just search their sites for 'Dsub' and 'DB25' (for a 25 pin version). Charlie On Mon, Feb 8, 2021 at 11:06 AM Daryl Thompson wrote: > Awesome idea! Thank you sir! Any recommendations on the best place to buy > the d subs? > > On Mon, Feb 8, 2021 at 11:27 AM Charlie England > wrote: > >> ceengland7@gmail.com> >> >> On 2/8/2021 8:48 AM, Daryl Thompson wrote: >> > Need some thoughts from you guys. I am installing 8 Mitchell products >> > cluster gauges in a 1978 PA32-300 (fuel qty, oil press, oil tem, etc). >> > I am wondering if there are any disadvantages to using a molex 8 pin >> > connector with one side having the 8 power wires connected to it and >> > the other side with the single 20 AWG power wire to one pin location >> > and then use jumping wires to connect in series the other >> > remaining pins so as to power the entire set of 8 gauge clusters. Each >> > cluster draws 1/10th amp and 20 AWG wire is attached to the existing >> > 5A Inst Gauge C/B. The other alternative would be to use a bus bar >> > but I am very limited in locating a good place to attach a bar. Could >> > I also do the same for the grounding wires, i.e. 8 ground wires to one >> > side of the molex connector and other side with a single grounding >> > wire with jumped pins. The single ground wire (size?) would be >> > grounded to the frame. The entire installation will be receiving a 337 >> > field approval. Thoughts? >> The architecture sounds reasonable to me, but my personal choice of >> hardware would not be molex. I was an electronics tech in several past >> lives, and saw a *lot* of reliability issues with them, in a lot of >> different environments. In addition, jumping that many pins would be as >> big a pain as just jumping from instrument to instrument in the >> 'traditional' fashion of wiring instruments. >> >> My choice of hardware would be Dsub. The airframe side of the connector >> could be a molded solder cup style, allowing you to bridge an entire >> line of pins with a single bared wire for B+, and the same on the other >> line for ground. A 25 pin connector would likely take less real estate >> than a 16 pin molex. The instrument side of the connector could be the >> removable pin type of connector, making it easy to add additional power >> wires for each instrument. Similar idea to the 'panel ground bus' >> detailed in the AEC drawings, but with one row being the supply instead >> of ground. >> >> FWIW, >> >> Charlie >> >> -- >> This email has been checked for viruses by Avast antivirus software. >> https://www.avast.com/antivirus >> >> ========== >> - >> Electric-List" rel="noreferrer" target="_blank"> >> http://www.matronics.com/Navigator?AeroElectric-List >> ========== >> FORUMS - >> eferrer" target="_blank">http://forums.matronics.com >> ========== >> WIKI - >> errer" target="_blank">http://wiki.matronics.com >> ========== >> b Site - >> -Matt Dralle, List Admin. >> rel="noreferrer" target="_blank">http://www.matronics.com/contribution >> ========== >> >> >> >> ________________________________ Message 5 _____________________________________ Time: 10:19:15 AM PST US From: Daryl Thompson Subject: Re: AeroElectric-List: Molex vs bus bar Ok thanks Charlie On Mon, Feb 8, 2021 at 1:11 PM Charlie England wrote: > They're sold by just about every vendor that handles electronic > components, so it's hard to recommend just one. For the individual crimp > pin type, B&C would be a great choice. > > https://bandc.com/product-category/electrical-supplies/d-sub-audio-connectors/ > > For solder style (and crimp, as well), just about any of the 'usual > suspects'. Newark, Mouser, Digi-Key, Allied, etc. The highest quality > individual pins are like the ones B&C sells; known as 'machined pins', that > have gold plated contact surfaces. Some (not all) of the solder type > connectors will have gold plated contact surfaces, as well. Just search > their sites for 'Dsub' and 'DB25' (for a 25 pin version). > > Charlie > > > On Mon, Feb 8, 2021 at 11:06 AM Daryl Thompson wrote: > >> Awesome idea! Thank you sir! Any recommendations on the best place to >> buy the d subs? >> >> On Mon, Feb 8, 2021 at 11:27 AM Charlie England >> wrote: >> >>> ceengland7@gmail.com> >>> >>> On 2/8/2021 8:48 AM, Daryl Thompson wrote: >>> > Need some thoughts from you guys. I am installing 8 Mitchell products >>> > cluster gauges in a 1978 PA32-300 (fuel qty, oil press, oil tem, etc). >>> > I am wondering if there are any disadvantages to using a molex 8 pin >>> > connector with one side having the 8 power wires connected to it and >>> > the other side with the single 20 AWG power wire to one pin location >>> > and then use jumping wires to connect in series the other >>> > remaining pins so as to power the entire set of 8 gauge clusters. Each >>> > cluster draws 1/10th amp and 20 AWG wire is attached to the existing >>> > 5A Inst Gauge C/B. The other alternative would be to use a bus bar >>> > but I am very limited in locating a good place to attach a bar. Could >>> > I also do the same for the grounding wires, i.e. 8 ground wires to one >>> > side of the molex connector and other side with a single grounding >>> > wire with jumped pins. The single ground wire (size?) would be >>> > grounded to the frame. The entire installation will be receiving a 337 >>> > field approval. Thoughts? >>> The architecture sounds reasonable to me, but my personal choice of >>> hardware would not be molex. I was an electronics tech in several past >>> lives, and saw a *lot* of reliability issues with them, in a lot of >>> different environments. In addition, jumping that many pins would be as >>> big a pain as just jumping from instrument to instrument in the >>> 'traditional' fashion of wiring instruments. >>> >>> My choice of hardware would be Dsub. The airframe side of the connector >>> could be a molded solder cup style, allowing you to bridge an entire >>> line of pins with a single bared wire for B+, and the same on the other >>> line for ground. A 25 pin connector would likely take less real estate >>> than a 16 pin molex. The instrument side of the connector could be the >>> removable pin type of connector, making it easy to add additional power >>> wires for each instrument. Similar idea to the 'panel ground bus' >>> detailed in the AEC drawings, but with one row being the supply instead >>> of ground. >>> >>> FWIW, >>> >>> Charlie >>> >>> -- >>> This email has been checked for viruses by Avast antivirus software. >>> https://www.avast.com/antivirus >>> >>> ========== >>> - >>> Electric-List" rel="noreferrer" target="_blank"> >>> http://www.matronics.com/Navigator?AeroElectric-List >>> ========== >>> FORUMS - >>> eferrer" target="_blank">http://forums.matronics.com >>> ========== >>> WIKI - >>> errer" target="_blank">http://wiki.matronics.com >>> ========== >>> b Site - >>> -Matt Dralle, List Admin. >>> rel="noreferrer" target="_blank">http://www.matronics.com/contribution >>> ========== >>> >>> >>> >>> ________________________________ Message 6 _____________________________________ Time: 11:29:19 AM PST US From: Subject: RE: AeroElectric-List: EFIS Erratic Temp Readings Hi Mike, Can you remind us whether the engine is 'standard' mags & carb (or Bendix style injection), or if it has some combination of electronic ignition/fuel injection? It is a LOM engine with magneto's only and mechanical fuel injection. No electronics on the engine at all Mike Thanks, Charlie Virus-free. www.avast.com ________________________________ Message 7 _____________________________________ Time: 04:21:31 PM PST US Subject: AeroElectric-List: Re: Molex vs bus bar From: "user9253" Steinair also sells D-Sub pins. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500607#500607 ________________________________ Message 8 _____________________________________ Time: 05:04:30 PM PST US Subject: AeroElectric-List: Antenna Grounding From: "Eric Page" I think I know the answer to this question, but I'd like confirmation: does an antenna ground plane have to be electrically bonded to the airframe? The aircraft is a Kitfox, which has a steel tube fuselage. In an effort to keep the outside of the plane as clean as possible, I'm trying to put as many antennas as I can inside the fabric envelope. For example, the comm antenna... https://www.aircraftspruce.com/catalog/avpages/antennasystems.php ...is mounted inside the vertical stab. Other Kitfox builders have reported good performance with this antenna in the tail, despite a couple of steel tubes in the vicinity. Since the transponder and ADS-B antennas... https://www.aircraftspruce.com/catalog/avpages/ted_transponder.php --and-- https://www.aircraftspruce.com/catalog/avpages/monopole11-13561.php ...are so short, they'll easily fit inside the wings. I can fabricate a ~3" diameter ground plane from aluminum sheet for each of them, but there's no way to electrically ground those plates to the airframe if they're suspended inside the wings. Is that a problem, or is a good bond from coax shield to ground plane all that's needed? Thanks. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500608#500608 ________________________________ Message 9 _____________________________________ Time: 07:53:17 PM PST US Subject: AeroElectric-List: Re: Antenna Grounding From: "user9253" No, the ground plane does not have to be grounded to the airframe. Com antennas should be vertically polarized. The ANTENNA VHF-5 will work in a wing, but not very well. It might work well vertically in the tail. How about this antenna for $45? https://www.aircraftspruce.com/catalog/avpages/stainlessantenna.php You could make your own antenna. http://www.aeroelectric.com/articles/Antennas/DIY_Comm_Ant/DIY_Comm.html But for $45, it will be easier to buy one. Mount it vertically inside of the fuselage. It can either point up or down. Make a ground plane out of 4 wires going out in 4 directions. Keep the first half of the antenna away from airframe tubes. Use a SWR meter to check how well the antenna works. What engine are you using in your Kitfox? -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500610#500610 ________________________________ Message 10 ____________________________________ Time: 07:57:48 PM PST US Subject: AeroElectric-List: Re: Antenna Grounding From: "user9253" Did you mean 3 inch radius for the transponder antenna? 3 inch diameter is too small. The radius should be at least as long as the antenna. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500611#500611 ------------------------------------------------------------------------------------- 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.