Decca....."state of the art"?
Ah, yes.....Decca and the last remaining Consol Station in Norway....however could we have found Teeside without them!
For you youngsters out there.....
Consol was a radio beacon operating at 1 kilometer (300 kHz), with three fixed antennas in a row spaced a kilometer (one wavelength) apart. The antennas produced a complicated signal that allowed determination of the radial to the beacon. It performed a cycle of transmissions as follows:
* Broadcast of an omnidirectional beacon signal for 6 seconds, along with a station identification code, presumably in the form of Morse letters.
* A "break" of transmission for 2 seconds.
* Broadcast of a complex signal for 30 seconds that consisted of dots and dashes leading up to a tone. The radial was given by the number of dots and dashes before the tone.
* Another break of transmission for 2 seconds.
If the aircraft was on a track roughly perpendicular to the beacon, the navigator could get a fix on it at two different locations along the flight path and use simple triangulation to determine the aircraft's position.