This article is rated Stub-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects:

Military history: Technology / Russian & Soviet This article is within the scope of the Military history WikiProject. If you would like to participate, please visit the project page, where you can join the project and see a list of open tasks. To use this banner, please see the full instructions.Military historyWikipedia:WikiProject Military historyTemplate:WikiProject Military historymilitary history articles Associated task forces: /  Military science, technology, and theory task force Russian, Soviet and CIS military history task force

The E-3 APY-1 and APY-2 radars are not frequency hopping radars. They are second generation Pulse Doppler (digital filter), and operate on fixed frequencies. The frequency can be changed in each sector, but not on a pulse to pulse basis.

First generation Pulse Doppler radars (Original F-15) were analog filter radars. MonsieurET ( talk) 23:02, 31 July 2017 (UTC) reply