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
INDEX | Back to Main INDEX |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: 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 <art@zemon.name> 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:
>
> <IMG_20160921_192531.jpg>
>
> 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
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Problems Soldering DB-25 Connectors |
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
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | 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 <ira.rampil@gmail.com> 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
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: 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
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | 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
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | 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
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: 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
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: New smartphone app for pilots |
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
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|