They literally Sinified the ship. They took out every Russian radar and replaced it with Chinese equivalents. Two of these radars are ironically, Chinese copies or variants of such, such as the Type 382 replacing the Top Plate, and the Type 366 replacing the Mineral ME Bandstand. Others have a more Western European design legacy, particularly from CSF Thompson, now absorbed into Thales, namely the Type 344 replacing the MR184 for AK130 gunnery, and the Type 347G replacing the MR123 for the AK630 control. The Type 344 is the standard gun fire control radar used by the PLAN for all its ships, and the Type 347G is the radar used on the Type 730 and 1130 CIWS but can be installed separately from those. Likewise, all the ellipsoid antenna navigation radars that were the originals, were replaced by linear array bar shaped navigation radars, this being a typical change. The Russian EW suite is replaced by the standard Chinese set used with other PLAN ships, namely the Type 726-1 ESM, 726-2 ESM and 726-3 ESM, but I don't see the Type 726-4 decoy system however. The decoy system is something that needs to be added sooner or later. The pole behind the top radar is changed to something that's used on the 052D, but also seen in the 051B Shenzhen refit. This pole probably is for SIGINT and UHF/VHF ESM. The EO has been changed or add to like something the ones used on the Type 054A frigates. The SATCOMs you typically see on Chinese ships are also added, there should be at least two kinds or pairs, a smaller and a larger one, for Ku band and X-band respectively. I would expect that with all these changes, the sonars on the ship would have been changed to Chinese ones, with matching changes in the internal network and computer systems.I've been watching the Russian military for ten years and it's great to see these old soldiers get a new lease on life. Apologies for the unformed question - what changes did they make to these ships? Did they swap out the engines? I can see it has new anti ship missiles and Sino-RAM.
Literally, a Sovremenny with Chinese characteristics.
The additions is the HQ-10 launcher, and the Type 364 radar on the back. There is no direct Russian equivalent to the Type 364 radar, which is an intended as a medium ranged scanner and tracker specific for sea skimmer missiles, so that is a new thing that was installed on the ship, and is found in almost all PLAN warships as a standard fit. Then of course, you have the VLS. The Front Domes are reduced from six to four, and likewise, the originals are replaced by domestic copies that are compatible with the HQ-16 SAM. The Moskits are replaced by YJ-12s, another obvious step in the Sinification.
More than upgrades, these changes are meant to bring the ships in line with the current PLAN standards in terms of electronic warfare, radar and sensor use. It also brings the ships in line with training the crews with the rest of the fleet
The AK-130s and AK-630s are retained, though overhauled. Its likely the original engines are also retained, but overhauled.
The one thing I'm surprised is that they have not fitted some kind of new PLAN data com array that the PLAN has been retrofitting on as many ships as it can. Yet. Maybe that will happen during their service of 136 and 137. Even the other two, not refitted Sovremenny have been already been fitted with this antenna as you can see with Ningbo here. The new antenna is the one you see underneath the second window of the bridge to the left.
The second pair of ships present a difference from other Sovremennys. Kashtans replace the AK630s, and there is a second radar on the back, likely to be a second Mineral ME Bandstand to cover the rear arc. There is a question whether the Kashtans will be replaced by Type 730 or 1130. The second Bandstand on the rear can either be changed by another Type 366 Bandstand copy or a Type 364 radar.