The Tirpitz was equipped with FuMO26 sets (as well as Hohentwiel and Wuerzburg) during the time it was laid up from the X craft attack from Sept 1943 to March 1944. The large antenna FuMO26 sets had 30% more range than the FuMO27 sets it had from 1941 until late 43. The FuMO27 had a BB to BB range of ~30km prior to 1943. The early models such as mounted on Graf Spee and Gneisenau could easly track large warships to 25km. In 1938 trials on Graf Spee it proved it could track another Panzerschiff to 25km. The Gniesenau's Seetakt picked up and tracked the Renown at 25km in brutal weather on April 9th 1940. The second generation in mid 1940 gave a 20% increase in range above that baseline. The FuMO27 on Luetzow picked up and tracked Burnettes light cruisers from 29km at Barents Sea in late 1942. In tests of large antenna versions of Seetakt it could track PT's to 15km. Late war the Germans standardized the size of the ship targets to a 2,000 ton warship for range comparison purposes.

The prototypes for 125-150kw transmitters code named Gesela were finished by the end of 1943, but still needed some developmental work before sending it to the front. Gesela utilized anode modulation with a high voltage pulse delivered by a pulser. The GEMA radar had always used a unique range measuring technique with a precision delay line to compress incoming pulses, but that required precise and coherent coordination between sent and received pulses. With the standard transmitter the perfectly formed pulse of small amplitude was delivered to the control grids of the transmitting tubes by a Central Impulse Geraete and then amplified. This design could provide the necessary coherence and precision (this was why they dropped the magnetron from the design in 1936). This also was why the GEMA radar was so exceptionally accurate.

The unique range measuring system could still be used with Gesela but at the cost of some precision. The 400kw transmitter for Seetakt used a spark gap pulser but the timing was so scattered that the unique precision ranging method could not be used. A new range measuring and indication system had to be developed and this was given the code name Paris and Paris II. Paris and Paris II could provide a range accuracy of 100 meters, which was 4 times less accurate than the existing sets had attained by then. Bearing accuracy and resolution would be the same as the existing sets because these are determined by the lobe switching system and the antennas.

In May 1944 a Calias B Seetakt was equipped with a Paris II system and a Gesela transmitter module for testing. It could track destroyers to 40km, large ships to beyond 50km, and aircraft to more than 200km. There were 26 Paris modules completed before the end of the war of which 11 were known used for shore based sets. I don't know if Gesela or Paris modules were intergrated into existing Seeart sets aboard the remaining major warships. Since the existing fine ranging system could be used with Gesela at the cost of some precision, it would have been possible due the modular nature of Seetakt to piggy back it onto an existing system with the option of high power or standard power operation.

Parallel to the program to develop 80cm Seetakt at high power and super high power, was also a program to provide centimetric options for existing Seetakt sets. The high frequency components for 9cm or 3cm operation could be piggy backed into existing sets keeping the existing components for indication and so forth. Shore based Seetakt given centimetric operational options was given the codename Renner and ship based Seetakts were given the code name Segler. Segler D was given for 3cm. A Renner was tested against the standard Calias B, also in May 1944. The Calais B at 80cm and 8kw could track a PT boat to 15km. The Renner version to 23km. Segler with conical scan was given a sub-fix of II. Therefore a Seetakt operating on 3cm would be named Segler II-D. The possibility existed to have a Seetakt set on a capital ship with three operational modes had the war lasted longer into 1945.

The bearing accuracy attainable by the 1940 series designs using Radattel Peilung lobe switching was 0.1*. This lobe switching was done through phased array manipulation of the receiving array of the antenna. Indication of the bearing was on a CRT with a null mark at the center of the display. The pip took a saddle shape and if the notch on the pip was on the null mark then the antenna was aimed dead on to the target. The pip wandered off the null mark if the aim was off to left or right.

This capability wasn't really usable on large warships until late 1941, but was used for blind fire as early as the fall of 1940 for shore based versions.

The bearing resolution is a function of the 1/2 power beam width. This can be calculated mathematically. WL/antenna size in dipole wavelengths (.75). In FuMO27's case it would be 80/10 (.75) =~6* FuMO25 would yield ~3.75* The (.75) figure is a corrective factor for the type of antenna. In this case a dipole array. It would be ~1.2 for a dish type antenna and the antenna size would be the dish's area on the horizontal coordinant in wave lengths. By using common mode antenna from late 1943 more dipoles are brought into the equation.

The range accuracy of early models using the fine range system depended in part on how far out the fine range indicator needed to be zoomed out. It was generally 100 meters in 1938. The 1940 models saw a significant improvement to about 50 meters. By 1943 typical range accuracy was +/-25 meters even with the fine range indicator zoomed out to display 300 meters of range. Range resolution of artillery specific models was as fine as 10 meters.

As stated above the range accuracy of Paris and Paris II systems was 100 meters.

The range discrimination using the fine ranging system (Messketten) could be as fine as 10 meters. This was a huge advantage for using Seetakt to spot the fall of shot and also to correct MPI errors. The way it worked in this context was that the pip was moved to the null mark at the center of the screen and held there (this procedure also electronically measured the range to target and continously updated it). Splashes falling short, or over, could therefore be discriminated from the target itself and by how far. The amount of time base presented on the screen was adjustable through zooming the screen in or out. For example, if you wanted to be able to see splashes as much as 150 meters short or long of the target, then you could set the screen to present 300 meters of range with the target located on the null mark in the exact center of the screen.

Coarse range monitoring, or overall monitoring of all targets within the scan sector, and the exact bearing to within 1/10 * of the selected target, was monitored on the Module PB indicator. Discrimination of shell splashes from the selected target for bearing was eqivilent to the 1/2 power beam width. This would be about 3* for FuMO26 or FuMO25. It would be about 6* for FuMO27. By way of comparison the bearing discrimination for Mk8 was 2*, and for Type 284M, 4.5*.

The maximum range that a radar can detect shell splashes is a complex equation depending on several factors as well as the size of and height of the shell splashes.

In the latewar British ASE documents they point out that detection of shell splashes was mainly the function of the minimum signal to noise ratio required for detection, or the sensitivity of the reciever in simple terms. This Min S/n ratio is in turn a function of the bandwidth of the reciever's IF (ZF in German) section(s) and how it is matched to the pulse width. The ideal amount of bandwidth is the inverse, measured in mhz, of the pusle width. For example, if the pulse width is 2 ms then the ideal bandwidth that gives the best possible S/n ratio required for detection, would be 1/2 mhz or 500 khz. The more this relationship is mismatched the greater the S/n ratio required for detection. Here German radars are generally well engineered because they are usually almost perfectly matched for bandwidth to pulse width. (By contrast British radars that used pulsers that deilivered a high voltage pulse to the anodes of either triodes or magnetrons required very high bandwidth to form and process a well shaped pulse. They thus required several times greater signal strengths to detect a target to a given range, unless the pulse widths were extremely short.) With Seetakt and Freya, the Min S/n ratio was also impacted by the amount the pulse was compressed by the precision delay line.

Other factors that may impact the range that a particular shell splash can be detected are related to the operating wave length. When KGV was bombarding Bismarck and the 284 radar was knocked out by recoil shock, they switched over to the 7.5 meter 279 radar. The 279 radar detected shells in flight and shell splashes better than the 50cm 284. This was because the shells length was a mutiple of the radars wave length. The reflectivity of a target is also impacted by wavelength. The radar cross section of a ship is greater with shorter wavelengths, because the antenna gain will usually be much greater. But the radar cross sections of aircraft are usually much greater, with longer wavelength radars. Generally, the range of detection overall increases with longer wave lengths, as long as the antenna gain is not significantly decreased, or a vertical lobes structure isn't formed in the case of detecting ships. This is reflected in the radar equation by placing wavelength squared in the numerator.

The type of indicator may also have an effect on the max range for detecting shell splashes. If there's much noise or sea clutter present then it will be easier to discriminate the shell splashes from the noise on an A-scope, than it would be on a PPI. This is because the noise will be presented as grass along the bottom of the A-scope and the shell splash amplitude will be much greater than the average noise, but on a PPI the noise will dispersed through out as snow.
The fine bearing and the phased array lobe on receive only system used by the FuMG40G series is well explained by von Kroge. Also Commander Giessler described that the operator used module PB for both target bearing and overall observation during his 1944 presentation. There are a few things that come to mind when talking about fine bearing system upgrades through 1942. The basic lobe switching and bearing indication system was expanded in 1942 to provide lobing on the vertical axis as well as the horizontal. There was also an alternative indication system provided to some Generation II Freya sets because Luftwaffe radar expert Diehl preferred the old indication system of comparing pips which the first generation GEMA radars used (Peilung verfaren A/N, which 1st Gen Seetakt did not normally use aboard ship, but was used by Calais A). The alternative indication system still allowed a comparison form of presentation, but with the new lobing technique.

They may well have needed to supply additional modules after the new AEG antenna traversing equipment was installed on the major warships beginning in mid 1941 and into 1942 , following Bismarck's loss. Different applications may have required more extensive modules as well.

BTW, Bismarck always had FuMG-40G series of radars (later designinated FuMO27). This is proven by the test reports of the radars putting out 9kw with a PRF of 500.