Wow…looks quite impressive compared to the competitors:
http://www.tek.com/spectrum-analyzer/rsa306
http://www.tek.com/datasheet/rsa306/rsa306-usb-real-time-spectrum-analyzer-datasheet
Even with interferer hunting feature: “SignalVu-PC Option MAP enables interference hunting and signal strength
analysis. Locate interference with azimuth direction function. It lets you
draw a line or an arrow on a mapped measurement to indicate the direction
your antenna was pointing when you take a measurement. You can also
create and display measurement labels.”