Skunk;194094 Wrote: > Not sure where I got AndyC772, there must be a couple of you here. > > Your instructions were really helpful, or will be once I get the tool > that is. The only thing holding me up is the thought of BNC connectors.
Thanks. BTW, the only reason I got the more expensive adjustable Canare cable stripper was because I wanted to use the Belden 89259 cable. This cable does not have dimensions that match any of the standard Canare cables. If you use the Canare cables, you can find out which one of the non-adjustable strippers is needed and save money by getting the cheaper non-adjustable ones. See the Canare catalog for more details. > Does anyone who's done the BNC mod think it's worth it over good cable > and 75 ohm RCA jacks? Do 75 ohm RCA jacks actually exist? I shudder to > think how much they might cost if so. I haven't done a BNC mod, but I'm familiar with the RCA impedance issue. Assuming the connector geometry is just concentric cylinders (outer conductor, dielectric and inner conductor), the diameter of the pin of an RCA plug is so large that getting a 75 Ohm impedance is physically impossible. The capacitance per unit length is too large. There's a specialized 75 Ohm RCA plug/jack combo available from one of the exotic cable vendors (can't remember which one). They get a true 75 Ohm impedance by removing some of the ground area, reducing the capacitance. This requires matching RCA plug and jack. Since it requires replacing the jack anyway, it makes more sense to get a 75 Ohm BNC. Note that there are both 50 Ohm and 75 Ohm BNC plugs and jacks available. Be sure to get the right ones if you do this. Canare claims very good VSWR for their RCA plugs, but I think they are playing games with the spec. If you move the VSWR reference plane back to before the transition from the small-diameter cable center conductor to the fat pin, it will make the VSWR data look very good. This suggests that the mismatch error is largely lumped into the jack. The jacks do indeed measure much poorer VSWR than the plugs, so I suspect this is what they are doing. -- andy_c ------------------------------------------------------------------------ andy_c's Profile: http://forums.slimdevices.com/member.php?userid=3128 View this thread: http://forums.slimdevices.com/showthread.php?t=32988 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
