Hi Dick, An EZNEC and SimSmith model of the on ground 1/4 wave vertical: https://www.kn5l.net/images/SS-KA5KKT-vertical.png
SimSmith R1 represents ground loss, the value set to establish a 50 ohm load at the transmitter, G in SimSmith. According to the models, the 7 to 7.3 MHz SWR is a little below 1.3. A flat measurement using the K3 SWR meter seams reasonable. My suggestion is to use a Antenna Analyzer to measure the antenna and system. John KN5L On 12/2/18 12:16 AM, Dick Dickinson wrote: > I have a full-size monoband vertical for 40 meters. Simple architectural > aluminum tapering from 1 ¼” (?) in 6’ telescoping sections. The radial > field is designed to provide a 50 ohm match at the feed point…12 – 13’+ > radials. It is fed directly…no matching device with RG-213 from the remote > antenna switch about 50’ away at my tower. The coax from the rig to the > remote antenna switch is estimated to be ~ 50’ in length. A lot of the time > running K3EZ to sweep the band (typically 20 watts), it will indicate a > 1.0:1 SWR from 7.0 MHz to 7.3 MHz in 20 kHz steps. Occasional deviation > from one K3EZ run to another might be due to variations in moisture content > of the ground or less than perfect connection to the vertical…an uncommon > situation. The K3 shows the same readings. > > Is this 1.0:1 SWR across the entire 40 meter band curious or remarkable? ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
