"SJ" and "SD" radar - what does it stand for?

[Raptor1]

I also believe that it does not stand for anything, I think surface ships' equivilant was called the SG Radar, and the model that succeded the SD Radar was called the SV Radar...

The S stood for S-Band while the other letter stood for the model as far as I know

[kylesplanet]

The SD radar got its name from the crew. Each time the radar picked up a plane the crew screamed SH*T! DIVE!!! Hence the acronym, SD.
:rotfl: :rotfl:

[V.C. Sniper]

^ I LUL'D!!1!1 :rotfl: :rotfl: :rotfl:

[Nisgeis]

There are two main groups of radar, search and fire control. Fire control radar is prefixed with an F and search radar is prefixed with an S. The second letter is usually the model of search radar, so the SJ radar is search radar, model J (model 10). Fire control radar used to be denoted by letters, but was standardised to be numbered instead, so what used to be called an FC or FD would subsequently be called just a Mark III or Mark IV.

Any number after the S<letter> system is a modification. So, SJ-1 is the first modification to the SJ radar set, which increased range.

[Able72]

Wow, some of you guys know more history about military equipment than a sane human being should

[Raptor1]

Originally Posted by Able72

Wow, some of you guys know more history about military equipment than a sane human being should

Being a sane human must be boring then...

Anyway, Nisgeis, I think your right about the S standing for Search and the other letter standing for the model number, but the earliest type of US Shipborne Search Radar used in WWII was called the CXAM (Though I think the CXAM-1 was more widespread), which was introduced before the S models, What did that stand for?

[MonTana_Prussian]

Originally Posted by Raptor1

Being a sane human must be boring then...

Anyway, Nisgeis, I think your right about the S standing for Search and the other letter standing for the model number, but the earliest type of US Shipborne Search Radar used in WWII was called the CXAM (Though I think the CXAM-1 was more widespread), which was introduced before the S models, What did that stand for?

Actually it was XCAM,and I don't know what it meant. I do know that USS Enterprise had it early on.

[LukeFF]

Originally Posted by Nisgeis

Any number after the S<letter> system is a modification. So, SJ-1 is the first modification to the SJ radar set, which increased range.

Kind of. Any number following the two-letter prefix denoted a factory modification. A lower-case letter denoted a field modification. In reference to WWII radar, SJ-a was a field-modified SJ radar set modified with a PPI screen, and likewise SD-a was an improved version of the original SD (what is known as "improved SD radar" in SH4).

[Nisgeis]

Originally Posted by LukeFF

Any number following the two-letter prefix denoted a factory modification. A lower-case letter denoted a field modification. In reference to WWII radar, SJ-a was a field-modified SJ radar set modified with a PPI screen, and likewise SD-a was an improved version of the original SD (what is known as "improved SD radar" in SH4).

I typed out the thing about field mods and then deleted it, because I can't remember the source I got that from and I'm not actually sure I ever did see one. Do you happen to know of a source for that field mod convention?

[Raptor1]

I know that USS North Carolina and USS Washington we're refitted with SG Radar in 1942, But does anyone know if the pre-war Carriers retained the CXAM-1 or we're they also refitted with a more advanced set (And if so, when)?

[LukeFF]

Originally Posted by Nisgeis

I typed out the thing about field mods and then deleted it, because I can't remember the source I got that from and I'm not actually sure I ever did see one. Do you happen to know of a source for that field mod convention?

Norman Friedman talks about it in his book for both SD and SJ radars, in the footnotes for his chapter on WWII.

[JetSnake]

Originally Posted by Nisgeis

There are two main groups of radar, search and fire control. Fire control radar is prefixed with an F and search radar is prefixed with an S. The second letter is usually the model of search radar, so the SJ radar is search radar, model J (model 10). Fire control radar used to be denoted by letters, but was standardised to be numbered instead, so what used to be called an FC or FD would subsequently be called just a Mark III or Mark IV.

Any number after the S<letter> system is a modification. So, SJ-1 is the first modification to the SJ radar set, which increased range.

[Austin Powers] Nerd Alert!!!! [Austin Powers]




Thanks for that explanation!

[Crosseye76]

Here is one from the Wiki on CXAM radar:

"
The CXAM radar system was the first production radar system deployed on US Navy ships. It followed several earlier prototype systems, such as the NRL radar installed in April, 1937 on the USS Leary (DD-158); its successor, the XAF, installed in December, 1938 on the USS New York (BB-34); and the first RCA-designed system, the CXZ, installed in December, 1938 or January, 1939 on the USS Texas (BB-35). Based on testing in January, 1939, where the XAF was more reliable, the US Navy ordered RCA to build six XAF-based units for deployment and then shortly thereafter ordered 14 more.
The first six units RCA produced (delivered in 1940) were denoted "CXAM" and were a fusion of XAF and CXZ technologies. These were installed on the USS California (BB-34), the USS Yorktown (CV-5) (in September, 1940), and four cruisers. The next 14 units RCA produced (also delivered in 1940) were denoted "CXAM-1" and were slight improvements over the CXAM design. These were installed on the the USS Texas (BB-35) (in October, 1941), USS Pennsylvania (BB-38), USS West Virginia (BB-48), USS North Carolina (BB-55), and USS Washington (BB-56); on the aircraft carriers USS Lexington (CV-2), USS Saratoga (CV-3), USS Ranger CV-4), USS Enterprise (CV-6), and USS Wasp (CV-7); on one heavy cruiser; on two light cruisers; and on the seaplane tender USS Curtiss (AV-4).
Radar detection range of aircraft depends on altitude, size, and number of aircraft. The CXAM is listed (in U.S. Radar, Operational Characteristics of Radar Classified by Tactical Application) as being able to detect single aircraft at 50 miles and to detect large ships at 14 miles. Other sources list CXAM detection range on aircraft out to 100 miles.
The US Army's first non-prototype radar system, the SCR 270 radar, was developed in parallel with the CXAM."


Even though the Wiki calls them 'production' sets, I think they were still pretty much prototype sets or low-rate production test sets to try them out in the field, and the designation seems to reflect that. When the first real production line sets were made in large quantities, they were given the standard designations.

[Raptor1]

"Production" might be misleading, I think the proper term would be "Operational"...