I was beaten to the door on this. Actually there is a spot up about one third wavelength that is 100 ohms,for a perfectly resonate radiator. So it would be 2 to one and a dandy perfect resonate vertical with over a hundred radials is about 35 ohms so the magical 1 to 1 is nothing magical. I would beg everybody to read at least two chapters of Walt Maxwell's book " Reflections". The right SWR for the wrong reason, and the Wrong SWR for the right reason. The first I would call dummy load syndrome and the second as above. This stuff is not opinion or politics it is pure science and can be tested at YOUR house.. 73 Mike
----- Original Message ----- From: "Gary Schafer" <[EMAIL PROTECTED]> To: "'Discussion of AM Radio'" <[email protected]> Sent: Thursday, April 20, 2006 10:12 PM Subject: RE: [AMRadio] antenna tuners > This is another tidbit to keep in mind for those that still may think that > an antenna has to be resonant to give 1:1 swr. > > A dipole antenna rarely is 50 ohms at resonance. It is very dependent on > height above ground as to what impedance it presents at the feed point. It > can range anywhere from below 30 ohms to above 70 ohms. > > So if you cut your antenna so that you have 1:1 swr at the transmitter end > of the coax, the antenna is probably not tuned to resonance! You have > detuned the antenna to change its impedance that the coax sees. > > Only rarely does a resonant antenna turn out to be 50 ohms. > > 73 > Gary K4FMX > >
