I totally agree with that Bob. I believe the dissimilar metal *thing* has far less to do with generating noise and PIM, than the simple fact that we have separate wires and elements constructing the shield that have very bad electrical connections with each other.
Aluminum is known to always form a non-conducting oxide on it when exposed to air. Non-silver plated copper braid wires can have the same problem, though not quite as readily if kept dry. In any case, there are thousands of potential diode mixers per foot of cable. I too, use only silver-plated braid or solid copper such as Superflex. I'll never forget the piece of RG213 that I once had feeding a repeater antenna that easily generated noise when taken in hand and flexed. I say all the good luck to those that successfully use 9913 and similar cables in duplex service. I'll use cables that are virtually certain to *not* generate duplex noise in my installations. Laryn K8TVZ > BTW, they don't need to be dissemilar metals. I once confirmed a 100% > copper braided RG-213 jumper as a PIM source. I only use silver-plated > braided coax beyond the duplexer from now on. > > Bob NO6B >
