---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 09/22/16: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:21 AM - Re: Problems Soldering DB-25 Connectors (Sebastien) 2. 05:31 AM - Re: Problems Soldering DB-25 Connectors (racerjerry) 3. 05:46 AM - Re: Re: New smartphone app for pilots (Ryan Brown) 4. 06:50 AM - Re: Problems Soldering DB-25 Connectors (Robert L. Nuckolls, III) 5. 07:04 AM - Re: Re: Problems Soldering DB-25 Connectors (Robert L. Nuckolls, III) 6. 08:03 AM - Speaking of solder . . . (Robert L. Nuckolls, III) 7. 08:06 AM - Re: Problems Soldering DB-25 Connectors (Robert L. Nuckolls, III) 8. 09:51 AM - Re: New smartphone app for pilots (rampil) ________________________________ Message 1 _____________________________________ Time: 02:21:36 AM PST US From: Sebastien Subject: Re: AeroElectric-List: Problems Soldering DB-25 Connectors You and everyone else who hasn't spent a lot of time practicing soldering th em. Two choices. Keep trying until you get it right or my favorite: Get rid of the solder connectors and order some crimp ones. Sebastien > On Sep 21, 2016, at 20:33, Art Zemon wrote: > > Folks, > > I am trying to solder 20 gauge wire into DB-25 connectors and having a tou gh time. The conductors just barely fit into the cups on the backs of the pi ns when everything is "dry," before tinning. After I tin either one, pin or w ire, I cannot get all of the conductors into the cup. I end up with somethin g like this: > > > > I'm afraid that those are not acceptable. What do you think? > > If they are not acceptable, what is the solution? Can I trim a few conduct ors away so that the remainder will slip into the cup? Or should I just give up and switch to crimp pins? Or what? > > Thanks, > -- Art Z. > > -- > http://CheerfulCurmudgeon.com/ > > "If I am not for myself, who is for me? And if I am only for myself, what a m I? And if not now, when?" Hillel ________________________________ Message 2 _____________________________________ Time: 05:31:37 AM PST US Subject: AeroElectric-List: Re: Problems Soldering DB-25 Connectors From: "racerjerry" To tin the wire, I first clamp the stripped wire into my padded vise. After applying solder, I immediately wipe the tinned end to remove any excess solder. I use an old washcloth. Reapply heat, pinch the rag between thumb and finger around the wire and pull straight off the conductor. This should result in no stray strands and minimum solder. -------- Jerry King Read this topic online here: http://forums.matronics.com/viewtopic.php?p=460661#460661 ________________________________ Message 3 _____________________________________ Time: 05:46:43 AM PST US From: Ryan Brown Subject: Re: AeroElectric-List: Re: New smartphone app for pilots What? In 2012 there was a single Nexus model with a barometer. According to gsmarena.com it's now included in 132 Android phone models, including the S5 and S6. But we've also got dozens of free altimeter apps in the play store, so don't feel bad about leaving us Android folks hanging. On Wed, Sep 21, 2016, 7:25 PM rampil wrote: > > Hi Bill, > > You are absolutely right. These apps don't run on Android yet. > I am only a one man shop and that unfortunately requires setting > priorities. I might, however, point out, in defense of my choice, > that it is only quite recently that a single Samsung 7 series was released > with the barometer hardware. So it's not quite a massive > market yet. That being said, I do have a copy of the Xamarin > cross-development system, and playing with it is in the queue. Stay tuned. > > -------- > Ira N224XS > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=460649#460649 > > ________________________________ Message 4 _____________________________________ Time: 06:50:25 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Problems Soldering DB-25 Connectors At 07:33 PM 9/21/2016, you wrote: >Folks, > >I am trying to solder 20 gauge wire into DB-25 connectors and having >a tough time. The conductors just barely fit into the cups on the >backs of the pins when everything is "dry," before tinning. After I >tin either one, pin or wire, I cannot get all of the conductors into >the cup. I end up with something like this: Then don't 'tin' them first. In my Shop Note for dealing with solder-cup d-subs, I suggest tinning before dropping it into pre-filled cups. With 22AWG, the fits are not so tight and the process works well. When the stranding is tight, as with 20AWG, it's better to dry fit then solder. Bob . . . ________________________________ Message 5 _____________________________________ Time: 07:04:16 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Problems Soldering DB-25 Connectors At 08:22 PM 9/21/2016, you wrote: > >Be careful about dry joints, the solder should be bright and shiny all around >the joint. . . . which is easy to achieve with 63/37 solder featuring quality flux. > If the wire is carrying just signal, clipping a strand or two should >be fine . . . I've attached 18 AWG wires to solder-cups by trimming back excess strands. This was a system with long runs of wire where voltage drop was an issue. There are companies that make special adapters to put too-large wires into 20AWG solder-cups but trimming the strands is more compact and works good too. > (with adequate strain relief). The backshell is were wire-support takes place. Heat shrink is more of a hedge against pin-to-pin shorts by conductive contaminants . . . a thing that just doesn't happen in a clean work environment. >Power carrying wire demand more careful consideration >about potential resistive heating and voltage drop. Sort of . . . but pin-to-socket interface within the connector is the driving concern about path resistance. 20AWG wire is 10 milliohms per FOOT, 22AWG is 16 mOhms/Ft. A single pin-to-socket interface on a d-sub can present 3 millioms of resistance over a millimeter. Variability in resistance between pin-to-socket interface within a connector gives rise to the prohibition for paralleling pins to increase current handling of any one path. I designed and qualified a paralleled d-sub pin process at Beech that was used in both targets and production aircraft. This involved EXTENDING each pin in a paralleled array with say 12" of 22AWG wire before the pin-paths were joined in parallel. This ADDS 16 milliohms resistance to each 1-3 milliohm pin-to-socket variability. This 'ballasting' resistance forces the sharing of current across an array of paralleled pins. The short answer is that concerns for heating due to current flow reside in the pins . . . not the wires. Bob . . . ________________________________ Message 6 _____________________________________ Time: 08:03:44 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Speaking of solder . . . We've had many discussions on the List over the years concerning soldering materials, tools and techniques. I own perhaps a dozen tools intended to effectively heat solder and the target work piece(s). I use solders of several types for both electronic and mechanical joining. For about the last 15 years, Metcal solder stations have been my favorite tools for joining everything from specks of electronic fly-dung on etched circuit boards to installing terminals on 4AWG wire. Metcal stuff has been readily available on eBay and I've pretty well outfitted the tool boxes of myself and relatives with these tools. I had recently had occasion to enhance a product development partner's tool compliment and decided to try a prominently promoted product line I saw on eBay. http://tinyurl.com/zddlb2t I bought one for the project . . . and a few months later, added another to my drive-stand bench. These have proven VERY capable. Good temperature control, good energy concentration at the tip, reasonably priced tips in range of sizes and shapes. I've found them to be a good value and more readily available than the older Metcal system products at similar prices. I think Hakko may be the Metcal of the Pacific Rim. They have a broad range of products and are widely represented. I can recommend them as an alternative to Metcal. Bob . . . ________________________________ Message 7 _____________________________________ Time: 08:06:51 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Problems Soldering DB-25 Connectors At 07:33 PM 9/21/2016, you wrote: >Folks, > >I am trying to solder 20 gauge wire into DB-25 connectors and having >a tough time. The conductors just barely fit into the cups on the >backs of the pins when everything is "dry," before tinning. After I >tin either one, pin or wire, I cannot get all of the conductors into >the cup. I end up with something like this: Art, if you do not have 63/37 solder of known pedigree, drop me your mailing address and I'll send you enough to do a handful of d-dsub jobs . . . having a good solder is 75% of the task, good iron is 20% thus making your probability of success in mastering the last 5% more of a sure thing. Bob . . . ________________________________ Message 8 _____________________________________ Time: 09:51:01 AM PST US Subject: AeroElectric-List: Re: New smartphone app for pilots From: "rampil" So much for my Android "guru" Just out of curiosity, any of those play store apps have a kollsman window for altimeter setting and density altitude and performance computations? -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=460669#460669 ------------------------------------------------------------------------------------- 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.