Hi Didier, I believe you are mistaken about what holds a crimp SMA connector together. The crimp force is entirely taken up in trying to constrict the circumference of the solid copper jacket. Because a cylinder is one of those perfect structures discovered by the ancients, this crimping pressure doesn't apply a significant amount of additional pressure to the center insulator. I have made numerous shielded opens for network analyzer use by crimping an SMA connector nut onto a piece of copper semi-rigid shield tube without using any center insulator, or center pin.
The screw on BNC's that you can get at Radio Shack hardly qualify as a connector. -Chuck Harris Didier Juges wrote: > ); SAEximRunCond expanded to false > Errors-To: [EMAIL PROTECTED] > > I was referring to the crimp connectors like the SMAs where the cable is > press-fit in the connector. These work well at t=0 and in low stress > equipment, but are not too good in high vibration or thermal cycling > environments. > > Also, I believe the deformation of the outer conductor where the 1/4" > semi-rigid cable is squeezed introduces impedance changes and reflections. > Since most of these cables have Teflon insulation, cold flow and thermal > expansion create additional problems. These problems are not eliminated by > using solder type connectors though, as I have seen a number of soldered > SMAs with cracked solder joint. > > They are very easy to apply though, considerably easier than the solder > types, and you are less likely to let a badly crimped connector go through > inspection than a badly soldered one. Problems tend to be obvious. A cold > solder joint, or too much heat applied to the cable (melting the insulation) > while soldering are much harder to spot. > > I have occasionally used crimp BNC connectors and they were as you describe > for the most part. Other than that, my personal experience is mostly with > solder-type coax connectors. > > The cheap but not inexpensive screw-on BNC connectors you can find at Radio > Shack do not have an inner sleeve either, if I recall correctly. Not that I > would recommend using those for ANYTHING (well, I had to try them, so I > did....) > > Didier KO4BB _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.