Radio Compass Station NLG
It all began with a plank of wood. The plank was from a shipping case. Stenceled upon it was the address: "Radio Compass Station NLG, Point Reyes". That was a challenge if ever there was one. Since Point Reyes is the home of the KPH receive site we thought we knew the radio history of the area. But NLG was new to us. Luckily our library contains an ITU book from the 1930s covering radionavigation stations. And there it was, NLG Point Reyes, complete with the latitude and longitude. The coordinates were plugged into a GPS and the little arrow was followed to... Well, see below for what was found.
A strict procedure applied to the process for obtaining a radio bearing from a radio compass station. All communications took place on 800m (375kc). Stations that were part of a harbor entrance group, as NLG was, had a single control station that communicated with the ship. The ship began the process by calling the compass station on 800m and sending QTE? (what is my bearing?). The call was answered by the compass station or control station which, when ready to take a bearing, sent K (invitation to transmit). The ship then sent its call repeatedly for 50 seconds with the dashes considerably prolonged. Signals such as V or MO were not authorized for bearing purposes. The radio compass station then sent the bearing, or multiple bearings in the case of a harbor entrance group of stations, to the ship. These were plotted on a chart to fix the ship's position with appropriate corrections to correct for angular distortion at ranges over 50 miles if a Mercator chart was used. Accurate bearing were generally available out to a range of 150 miles. ("The Radio Manual", George E. Sterling, 1928 pp 505-507)
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