--- In Repeater-Builder@yahoogroups.com, John Sehring <wb...@...> wrote: > > There seems to be confusion & mystery in the crowd of radio buffs that I han out with (not in this group!) on the subject of connecting cable lengths for cavity & duplexer use. I've heard that the manufacturers of such devices also tend to be mum on this.
These sets of cables are generally known (where I come from) as "critical length harnesses". > It seems to me that if these devices are tuned up to perform their function(s) (notch, peak, bandpass, bandreject, etc.) with 50 ohms of pure R in & out as source & load Z, cable length ought not make a difference (within reason, I'm not talking long cables with significant losses) to their performance. > > Is this so? Am I missing something? Thanx! Common sense would say you're right on the money. However, I think that common sense only applies if the velocity factor of your cable is 100%. There's also something to do with the "shape" of waves travelling along it, and voltage/current minima and maxima, I suppose :-)
