O.K....P.P.S. (And more to the point); I twist the wires together as tightly as I can, and then a bit less on the next pair, and so forth. I try to make sure that each pair is twisted tightly enough to allow the board/unit in question to stand up using just these wire pairs and then mount the board with plastic "hardware".
On Sun, Dec 6, 2020 at 2:10 PM Bob Finch <[email protected]> wrote: > > Hey Will; > > If you place groups of wires together...twist them as "pairs" > separately, i.e. B+ and B- (ground) together, and each pair of signal > + and signal - (charge firing) together, and so forth. IDEALLY if you > then are forced to place these pairs adjacent to one another AND they > have a slightly different twist "rate" (amount of twist per > "unit-of=-measure") things will be as good as you can get. > ("Crosstalk" between pairs will be minimal as you can make it.) > > In the confines of a "electronics bay" this may seem a lot more > theoretical than useful, but it forms good engineering practice, and > ignoring the above rules completely can contribute to an "ebay cato". > How so: > > When so twisted the wires can "take shape" so that the > printed-circuit-board can be held in place by the wiring alone. So > when the brunt of excessive g forces breaks the plastic screws you > used for mounting (I know, everyone is a perfect flyer, so taking > "hard landings" into account may seem "excessive".....grin.), you now > have a chance of recovering a working unit....... !! (Ask me how I > know.....er, um, another time please !) > > Anyways, my input......hope it helps you fiqure this out. > > Fly high, fly fast, fly safe....not nec. in that order. > > VERY best regards; > > Baab F. > > P.S... Shielding is not as useful as twisting on "balanced" circuits > when considering coupling between each (non-coaxial) wire (or circuit) > -pair, This is due to the lack of a third (tertiary) path on these > two-wire circuits. > > On Sun, Dec 6, 2020 at 11:36 AM Will Marchant > <[email protected]> wrote: > > > > Hi Folks: > > Any "rules of thumb" about how much twisting to do of the various > > avionics wires? > > > > One turn per inch? More? Less? > > > > Thanks in advance for any advice! > > Happy holidays, > > Will > > > > -- > > Will Marchant, KW4WZ > > [email protected] > > http://www.spaceflightsoftware.com/will/ > > _______________________________________________ > > altusmetrum mailing list > > [email protected] > > http://lists.gag.com/mailman/listinfo/altusmetrum _______________________________________________ altusmetrum mailing list [email protected] http://lists.gag.com/mailman/listinfo/altusmetrum
