I used various features of the analyzer to profile the SWR of my 80 m horizontal loop antenna. The analyzer settings default to measuring 600 points across the designated frequency range, whose default is 1 to 35 MHz. The 47-page user guide covers all the features, but it is very easy to use. There are convenient buttons to quickly select a single band for analysis. A scan of 600 points takes 25 seconds on my ham shack PC. The number of points to scan can be specified in the software. I found that 200 points still gave satisfactory displays, especially for a smaller frequency range. A table of the scan data is also available with the click of a button. Both the graphic display and the table can be exported easily. When the graphic is displayed following a scan, the mouse pointer can be moved anywhere on the graph to display numeric values of SWR and frequency.
Below is a scan of my 80 m loop with a 4:1 balun connected to the 450-ohm feeder. (Click on the image to enlarge.) The gray vertical bands mark the amateur radio band frequencies. The SWR curve has nice dips in or near the 80, 40, 20, 15, and 10 m bands, but not at 60 m. The SWR scale is on the right side, return loss on left side, and the frequency scan is from 3 to 30 MHz, with 600 points of data. A deep dip in SWR occurs near 10.6 MHz, and this is consistent with SWR data calculated from antenna modeling software.
Returning to the 4:1 balun, I tested the effect of shortening the feed line by 9 ft. The plot is shown below, and has the same scales as the previous plots. It is easy to see that the shorter feed results in the SWR dips moving higher in frequency. A closer examination of the table data would reveal whether the shift causes significant SWR increase within most of each affected band. The SWR at 60 m is not improved.