Hello Antonio,
Thank you for posting the excerpt from the PoW tactical plot tracing in your possession. Will you confirm for the others that there is no reference on it to any M/F D/F bearings from Suffolk transmissions or any other vessel after 03:36, and therefore none from the critical period 05;00-06:00?
Thus contradicting your own observation
and PoW measured bearing of Suffolk at 05.35 was 350°
My understanding is that there are three standards for bearing determination:
RDF transmitted energy sent to, and bounced back from the target ie radar (RDF as a name was meant to mislead and create confusion.) Dave Saxton can give us detailed chapter and verse for different sets' bearing performance.
HF/DF developed during the war, PoW may have had the FH3 receiver,an unreliable early set, which like other D/F depended on transmissions from the target. The high frequency waves allowed more accurate determination of bearing. The logged Suffolk transmissions may have come from this.
MF / DF a standard element of marine navigation since the First World War using frequencies allowing only much lower bearing accuracy and normally using triangulation to derive a cocked hat of bearings from fixed shore locations within which the vessel's position was........... somewhere. All the ships had this.
The metal hull of the vessel acted as a distorting aerial bending incoming radio waves by different amounts on different bearings in both the latter systems, and so periodically calibration was necessary, where the vessel anchored in a fixed location, with transmitters on known bearings and the error created by hull distortion mapped for 360 degrees from ships head.
This is the same process as the calibration of the ship's magnetic compass where magnetic field distortion from the shp's hull had to be compensated for.
See
http://nvlpubs.nist.gov/nistpubs/Scient ... 29_A2b.pdf for an early explanation.
Note ordinary single bearing transmissions of MF DF are so useful that Suffolk says:-
20. 0638 (B)-0734 (B). Course and speed as requisite for following enemy in general direction 210°, at 18 miles distance, and for working on to his starboard quarter, Norfolk being (from her reports) to port.
ie MF DF clearly fairly useless for locating Wake-Walker at all and left Ellis relying on Norfolk's transmitted position estimates to know whether CS1 was
north or south of him. Unless this a detail of the elaborate set of lies made up at the time, including recording the idea of ranging on the aircraft to explain why he though he was within gun range of Prinz Eugen, except he wasn't at that time, but he had been earlier, except he had to keep that secret, and make everybody think he hadn't...........
Another important point is that M/F D/F has nowhere near the accuracy of visual bearings. However like visual bearings there is no indication of distance. If an assumed position is charted then it cannot be solely due to a bearing because a single bearing cannot give a position.
traced by Pinchin on " The Plot " as well only partially and ending up on the water ( ???
??? )
of course the bearing ended in the water, Pinchin had no idea how far away Suffolk actually was. The bearings on the PoW tactical plot end in the water because the plotter had no idea how far away Suffolk was.
Antonio has been possession of the PoW tactical plot all along (something not many others might be aware of) and so he knows there has been no attempt on this document to correct retrospectively for dead reckoning errors for PoW, or to the the assumed tracks for Norfolk or Suffolk.
All the best
wadinga