HiIn photos I've seen of old planes (particularly seaplanes) such as the SO3C Seamew and the OS2U Kingfisher, the observer/radio operator (that guy in the back) station always has what looks to be an ADF loop antenna in the cockpit! Case in point:OS2U: http://upload.wikime...flight_1942.jpgSO3C: http://upload.wikime...with_floats.jpgThey might be hard to see b/c of the canopy glazing, but they are indeed there. They are just in front of the radio operator/observer/gunner. Much clearer view of OS2U back seat, complete with mystery antenna: http://www.google.co...=1t:429,r:3,s:0 http://navsource.org/archives/01/057/015768z.jpghttp://navsource.org/archives/01/057/015768z.jpgIf it is indeed an ADF reciever, why place it in the cockpit? I am no mechanic and no aircraft historian, but wouldn't that result in decreased signal strength? The waves would not only have to pass thorugh the air but through several inches of metal, glass and canvas to get to the reciever. Also, if it is NOT an ADF, what is it? A radio, perhaps?

Early direction finding systems were not automatic. The operator listened to the received signal through headphones and rotated the aerial to determine the direction if the ground station. Rotation was achieved mechanically so it would be convenient to position the aerial near to the operator.

It would appear to be a Bendix DU-1 direction finding antenna mounted over a Bendix RA-1B radio receiver.http://aafradio.org/docs/DU-1.pdfhttp://www.radiomilitari.com/ra1b.htmlscott s..

Here is a better view

Early direction finding systems were not automatic. The operator listened to the received signal through headphones and rotated the aerial to determine the direction if the ground station. Rotation was achieved mechanically so it would be convenient to position the aerial near to the operator.

On the subject of direction finders, how would you navigate by ADF in FS2004? Do you just dial in the NDB code into the ADF radio and just follow the needle?

On the subject of direction finders, how would you navigate by ADF in FS2004? Do you just dial in the NDB code into the ADF radio and just follow the needle?

Pretty much. Doing it that way would be known as homing.

Pretty much. Doing it that way would be known as homing.

I remember reading about a method of ADF navigation where you have to do some calculations based on your heading and the ADF course. How would that work? B/c I read that homing onto stations is really a bad idea.How would you use an RMI for VOR ops? An RMI does not have a CDI, so how would you know if you were straying from your desired radial?Source: http://www.navfltsm.addr.com/ndb-nav-adf-2.htm

If you turn the plane until the needle points straight forward is homing.If there is a crosswind it will make you fly a curved path.To fly a straight path you must crossreference the ADF needle with the directional gyro.Then you turn the plane to keep the needle pointed at the same bearing.If you know the direcion and speed of the wind you can calculate a correction angle and keep the ADF pointed at it.An RMI works similar to an ADF.It's compass rose will turn with the plane.The VOR needle will point out the radial that you are on.If you want to fly the 090 radial you need to keep the VOR needle on the 090 on the compassrose.