P4-58 is a Vintage Raytheon Navimatic Radio Direction Finder that was salvaged from a once working vessel and is now available for sale. These 2 were wired together. The small radio gave you the Direction that the signal came from, whether it was a radio tower/ beacon or a vessels radio signal. The lower unit (your present picture) gave the signal of the radio tower/ beacon which had a particular code to distinguish it from other radio towers. Normally a morse code signal which was assigned to a specific beacon. You would receive this signal and plot a single LOP (line of position) so you knew where you were. Another signal from a different beacon would give you 2 lines of position or a “cross” on a chart, that when plotted would identify your position with greater accuracy.
It is likely that this part was manufactured by the Sperry Corporation that was sold to Raytheon in the 20th century. The serial number on the back is faint but can be read as “221735”.
Height: 5.5 Inches
Length: 11.75 Inches
Width: 5 Inches
Weight: 4.5 lbs.
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