If it's good coax and you take some simple measures to ensure RF currents on the *outside* are suppressed, there should be no problem at all, either injecting xmit RF into other circuits or picking up noise from them. That sort of thing is done all the time in commercial layouts.
Good coax has dense shield. Cheap coax may have rather loose shielding covering perhaps only 70% or 80% of the inner conductor's insulation. That allows leakage of RF in and out of the shield. Normally it's not enough to cause real trouble, but when you want good shielding you need a good, dense shield. Coax braid should cover well over 90% of the center conductor. Since RF travels on the skin of the conductor, the RF currents on the outside surface of the shield are completely isolated from those on the inside surface (assuming it's good shield). In most Ham installations, RF currents on the outside are hard to avoid, since the end of the coax near the antenna is very close to it! When feeding a balanced radiator, like the center of a dipole, it's often recommended that the coax run away from the antenna at exactly right angles for at least 1/4 wavelength. That's to minimize RF currents on the outside of the coax shield. Strong currents will be induced on the outer shield by the close proximity of the antenna carrying strong RF currents, but, if the coax runs away at exactly right angles, the currents induced in the shield by one side of the antenna will be exactly balanced by the 180 degree out-of-phase currents on the other side of the antenna and no net current will flow on the outside of the shield. Some guys are lucky, but I easily can count the number of times I've been able to do that at home in the HF range: zero! The currents flowing on the outside of the coax can be suppressed though, using ferrite beads that slip over the coax (the famous W2AU balun is just such a device) or coiling the coax into an inductor of sufficient size to choke off the currents. If you do that where the coax enters your home, you should not have significant currents on the outside to bother any other electronics. Ron AC7AC -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Craig Rairdin So right now I run the coax from my HF antenna to a point just outside my window. When I want to operate I crank open the window and connect the coax from my rig to the end of the coax outside the window. I don't really have a way to leave it hooked up all the time because I don't want to leave the ground-level window partially open. I want to run the coax into the house through the wall, up the inside of the wall into the attic above my office, across the floor of the attic and down the inside of a wall to an existing utility box that is where all my phone and network connections are routed. This means I'll have coax running alongside both phone and CAT5. Seems like a lot of RF. I'm only running 100W. I suppose someday I might get some kind of amp but it's not a priority. But I don't want to rule that out simply because of the way I routed my antenna feedline. I can choose a different routing for the feedline and terminate it in a different box that's a few feet away from my CAT5 and phone lines, but I'd prefer not to have to install a new box. So my question is, is all that RF going to interfere with my network connection or my phones? Any thoughts or recommendations? Craig NZ0R KX1 #1499 K1 #1966 K2/100 #4941 K3/100 < #200 _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
