Fu. 30 a Richtkreis (Aiming Circle)
An WWII German radio direction finder must be properly set up with a compass, so the direction of a signal is correctly and accurately identified on a map. The problem is that EM radiation from the direction finder affects the compass needle. Enter the Fu. 30 a Richtkreis (and it's substitute - the Peilkompaß). The Fu. 30 a system was manufactured by Ertel-Werk of München as a 2-piece set: the Aiming Circle (Richtkreis) and the Aiming Sight (Richtausatz). The Aiming Sight was without a compass needle and was placed right in the center of the direction finding antenna. The Aiming Circle was set up 40 to 60 meters away from the direction finding receiver. Once the accurate degree direction was established on the radio direction finder, it was then adjusted on the aiming sight, and transferred over to the Aiming Circle to get an accurate compass bearing for a map reading. Both the Aiming Circle and the Aiming Sight could be operated at night with a battery power cable. Power requirements for the night illumination light are 2.5 Volt - 200 mA.



Outside of the box.



Top of the box.



Lid removed.



Lid removed.



The left view of the Richtkreis.



Right view of the Richtkreis showing the power connector for the night lighting system.



The front of the Richtkreis showing the compass window.



The manufacturer's data and the Waffenamt stamp.



The degree measurement scale with nonius.



Closeup of the compass window.



The built-in level.



This is a photo of a complete Fu. 30 a set from the collection of Guenther Hütter. On the left is the Aiming Sight, on the right is the Aiming Circle, in the middle are 5 spare light bulbs, and on top are the other accessories.



Here is a drawing of the Richtkreis from the manual.



The manual cover.