On Gneisenau KTB from 23 February 1941.
"1920 hours: Radar device locates Scharnhorst in 356º at 25,000 meters."
At this time both German battleships were operating in the North Atlantic against enemy merchant shipping.

alecsandros wrote:Thanks you, David,
25km for BB range is pretty good.
Any chance we might learn more about the conditions in which the range was measured ? Was it something normal for such a device ?
The call of the Navy for increasing the range of their Seetakt sets, for both sea surveillance and gun-laying, was more emphatic than that of the Luftwaffe. Their sets which used grid modulated transmitters with two decimeter wave triodes of the type TS6, gave a maximum range of 30km and obviously required increased power.
The range of FuMO27 mounted not as high as a foretop would be less of course, perhaps by as much as 30%.The development of the essential triode TS60 had been completed by the start of 1943 so (tube) production could begin. Siemens took over production of the new TS60 because GEMA's tube production for new radars and the supply of replacement tubes was over committed. By mid 1943 the development of the transmitter module Gisela was completed. This extended allowed power on (80cm) to 125 kw or 150 kw. In combination with a partial increase in antenna area where it was possible, this lead to ranges of the ship board sets of up to 60km, according to the size of the target ship. Even from U-boats the increasing of the transmitter power (to FuMO30) gave ranges of 20 km against sea targets, despite the low position of the antenna.
As I understand it all the radars were linked directly to the computers. This became standard procedure on all German warships. The aft computer on Hipper developed a fault in this connection from the aft radar, so the telephones had to be used, in one example.alecsandros wrote:It would be plausible to consider 30km as normal detection range, or maximum reliable detection range for capital ships ?
I'm asking because Hood was coming at almost right angles over Bismarck, thus presenting a smaller surface area to reflect the radar pulses than it would have been if the ship were on a parallel course.
And another matter: we have info from AVKS that the EM-II device was connected to the main battery computers. Any info on the situation of the 3 radars ? Were they all connected, or just the main one ? (foretop)
Standard radar cross section calculations for ships is cutting across them at a 45* angle, not broadside on. Radar reflectivity is highly dynamic. it is not just down to size and height. Anything can happen.The data wheels (of the new design) were so arranged as to allow selsyns for data transmission. ... This design proved itself and was a feature of subsequent equipment.