Wullenweber and other HFDF Sites

The Wullenweber Antenna is used for High Frequency radio Direction Finding (HFDF). It is a type of Circularly Disposed Antenna Array (CDAA) that's also known as a Circularly Disposed Dipole Array (CDDA). It had been nicknamed as the elephant cage. They were designed to receive radio signals between 2 and 32 MHz.

Most were built after WWII with the majority built in the Soviet Union and aligned countries. The antennas in the Soviet Union were called Krug (Russian for circle). There were numerous other designations used throughout the world such as FIX8, FIX24, Thick8, and others.

The U.S. military designations for the antenna and associated equipment was AN/FRD-9 (Army and Air Force), AN/FRD-10 (Navy), and AN/AX-16.

Wullenweber Antenna AN/FRD-10 Wullenweber Antenna
Drawings of antenna construction

These two drawings taken from Wikipedia illustrate the physical construction of the antenna and the dimensions:

Wullenweber Antenna Wullenweber Antenna


The map below shows the location of all the CDAA antennas including the Wullenweber, Krug, and variants. If it's a circular, high-frequency direction finding antenna, it's intended to appear on this map.

Help using Google Maps

The Full Screen control in the upper righthand corner of the Google Maps display expands the display to cover the entire computer screen. This full-screen feature is not available on Apple IOS devices like the iPad.

You can exit out of full screen by pressing the Escape key or clicking the control in the upper righthand corner of the display.

Map Satellite Labels

The Map/Satellite control in the upper lefthand corner of the screen lets you choose either the normal map view or the satellite view. The satellite view allows you to see the actual military facility when you zoom in. You can choose to turn Labels on or off. The labels are the names of places, businesses, cities, etc. that appear on the map. You can turn off the labels if they obstruct your view.

Map Satellite Terrain

When you select the Map view, you can turn on terrain features by clicking or touching the Terrain box. This will show things like mountain ranges, similar to looking at a relief map.

+ -

You can zoom in and out in a few ways. The lower righthand corner of the Google Maps display has a plus sign and a minus sign that controls zooming. If you're using a mouse with a scroll wheel, the wheel controls zooming. If you're using an IOS device like an iPhone or iPad, double-tapping the display zooms in but tapping does not zoom out.

Most touch screen devices will zoom by pinching the display with two fingers.

FLR-10   FLR-9   AX-16    KRUG    FIX8    FIX24    FIX40    THICK8    Misc 


Youtube: The Last Elephant Cage

Federation of American Scientists: AN/FLR-9

Wikiwand: Wullenweber

Wullenweber Antenna Arrays

Soviet KRUG and other CDAAs

— END —