WesWorld

Continuing from here.

First off, the quick and dirty primer of what historically took place, via wiki .

Quoted

Guglielmo Marconi initiated the research in Italy on radio-based detection technology. In 1933, while participating with his Italian firm in experiments with a 600 MHz communications link across Rome, he noted transmission disturbances caused by moving objects adjacent to its path. This led to the development at his laboratory at Cornegliano of a 330-MHz (0.91-m) CW Doppler detection system that he called radioecometro. Barkhausen-Kurz tubes were used in both the transmitter and receiver.

In May 1935, Marconi demonstrated his system to the Fascist dictator Benito Mussolini and members of the military General Staff; however the output power was insufficient for military use. While Marconi’s demonstration raised considerable interest, little more was done with his apparatus.

Mussolini directed that radio-based detection technology be further developed, and it was assigned to the Regio Instituto Electrotecnico e delle Comunicazioni (RIEC, Royal Institute for Electro-technics and Communications). The RIEC had been established in 1916 on the campus of the Italian Naval Academy in Livorno. Lieutenant Ugo Tiberio, a physics and radio-technology instructor at the Academy, was assigned to head the project on a part-time basis.[59]

Tiberio prepared a report on developing an experimental apparatus that he called telemetro radiofonico del rivelatore (RDT, Radio-Detector Telemetry). The report, submitted in mid-1936, included what was later known as the radar range equation. When the work got underway, Nello Carrara, a civilian physics instructor who had been doing research at the RIEC in microwaves,[60] was added to be responsible for developing the RDT transmitter.

Before the end of 1936, Tiberio and Carrara had demonstrated the EC-1, the first Italian RDT system. This had an FM transmitter operating at 200 MHz (1.5 m) with a single parabolic cylinder antenna. It detected by mixing the transmitted and the Doppler-shifted reflected signals, resulting in an audible tone.

The EC-1 did not provide a range measurement; to add this capability, development of a pulsed system was initiated in 1937. Captain Alfeo Brandimarte joined the group and primarily designed the first pulsed system, the EC-2. This operated at 175 MHz (1.7 m) and used a single antenna made with a number of equi-phased dipoles. The detected signal was intended to be displayed on an oscilloscope. There were many problems, and the system never reached the testing stage.

Work then turned to developing higher power and operating frequencies. Carrara, in cooperation with the firm FIVRE, developed a magnetron-like device. This was composed of a pair of triodes connected to a resonate cavity and produced 10 kW at 425 MHz (70 cm). It was used in designing two versions of the EC-3, one for shipboard and the other for coastal defense.[61]

Italy, joining Germany, entered WWII in June 1940 without an operational RDT. A breadboard of the EC-3 was built and tested from atop a building at the Academy, but most RDT work was stopped as direct support of the war took priority.

As a possible PoD from the original program (in addition to all the waves likely from other WW events that tend to sooth some of the historical wrinkles in the program), I would like to propose the involvement of Ducati from a early stage in up-scaling the program. Ducati being a major player in the Italian vacuum tube and radio manufacturing at this time (Motorcycle production begins to enter the company in the mid 1940's) in addition to FIVRE would have been able to provide additional resources that would have allowed for scaling up of both the research side of the program and production. Greater cooperation with Phillips via AEGIS ties are an additional possibility.

I have compiled a list of the WW-Historical uses of Radar by Italy that I know of. This list might not be complete as I am continuing to search, so I will update if new material presents itself. Note that I reference Naval radar as entering service over the range of ship construction as it has, AFAIK, not been documented differently then the Springsharp reports. Note several ships designed by RA did not note the specific fit. For the purpace of this exersize, I have made some assumptions based on ships of a comprible age.

First-Generation Sets (Introduced 1934-1937)

RaA.1 (Ship-based Air Warning), RaS.3 (Ship-based Surface Warning), GDR1 (Fire Control/Gunnery): These are found on the Litorrio and Rimini classes and are presumed to be on the Garibaldi, Alberto da Giussano, and Lombardia classes. I feel these sets are first kicks at the proverbial can and were not likely to be very good.

Second-Generation Sets (Introduced 1937-1941)
RaA.2 (Ship-based Air Warning), RaS.50 (Fire Control/Gunnery), RaA.50 (AA Fire Control/Gunnery): Used on the Tripolitania and Leonardo de Vinci classes and presumably the Pisa and Zara classes (tho they might use a mix of Gen-One sets). Given the classes they are noted as being on, I think that these are ment to be more specialized systems for Big-Gun Capital Ships.

GDR101 (Fire Control/Gunnery): Found on the Rimini class, I presume this is an attempt at a dedicated destroyer set.

Third-Generation Sets (Introduced 1939-1942, Current standards)
RaA.6 (Ship-based Air Warning), RaA.5 (Ship-based Air Warning), RaS.4 (Ship-based Surface Warning), GDR1R (Fire Control/Gunnery), GDR5 (Fire Control/Gunnery): These are the current standard, with various pieces being used on practically everything built, refitted or reconstructed since 1942.

Unknown Designation (Airborne Maritime Search): Mounted on Fiat Scorpions. First referenced by me in a Feb.1944 story.

So obviously there are a few gaps here, mostly in land-based radar. What I would like to do, is establish comparable OTL sets to the WW-Italian ones and then use those to help fill in the gaps in missing sets that could be presumed. Does this seem like a logical course of action?

It does appear to me to be a viable approach; I look forward to seeing your initial proposals.

For the initial go at this, I'm using British sets as detailed here to provide posible approximate analogs, as it provides a nice progression format with dates unlike its counterpart for the USN. These are not meant to be exact clones of the British systems.

RaA.6: Type 281
RaA.5: Type 279
RaA.2: Type 79
RaA.1: None suitable

RaS.4: Type 271P
RaS.3: Type 271 (Downgraded somewhat due to date difference)

GDR5: Type 285P
RaA.50: Type 285
GDR101: Type 273
GDR1R: Type 284P
RaS.50: Type 284M
GDR1: Type 284 (Downgraded somewhat due to date difference)

EDIT: The Airborne radar is something similar to the ASV II or ASV III

Thoughts?

Looks plausible enough to me, I'd need to dig out my British radar notes, but I've no worries at this stage. That RN wiki list is about the best I've ever found on WW2 radars.

The ASV radars and H2S etc. and one/ some of the naval radars (I think 271 but I'd need to check) shared the same transmitter etc. so its logical Italy could build a series of sets like the British did using common parts but different antennas etc.

I was not planing on aiming at major comonality with the Gen-3 stuff (yes with Gen-4 however), but if it is a side effect of my chosen baseline then alright.