DER's - Edsall Destroyer Escorts underwent modification to radar picket ships late in the war; unlike the DDR's, postwar they were a major component of US Naval Forces-CONAD. The class selected for the conversion was the FMR (for Fairbanks-Morse Reduction, ie, diesel-powered). As developed, the ships were scheduled to receive two AN/SPS-6B air search radars (one each fore and aft), two AN/SPS-8's, and a single AN/SPS-4 surface search. Due to equipment limitations, most went to sea with only one SPS-6B. The first two conversions were USS Harveson (DER-316) and USS Joyce (DER-317). Later mods brought a radar suite of a single SPS-6 on the after deckhouse, an AN/SPS-12 air search radar no the mast, and an AN/SPS-10 surface search radar. The last of 36 conversions - which included two WGT/steam geared-turbine escorts, USS Wagner (DER-539) and USS Vandiver (DER-540) - were completed in 1957. Small, slow and single-screwed, the ships were cramped but had the legs for extended picket duty off the Atlantic and Pacific coasts. Notably, their air defense armament was limited to a pair of single 3"50's, with one gun each fore and aft. According to Norman Friedman in US Destroyers: An Illustrated Design History (Annapolis: Naval Institute Press, 1982), everyone knew they were undergunned vis a vis AAW, but, "There would be little point in wasting part of a strategic attack force on a DER - which would provide first warning by its disappearance" (oh BOY!). The ships turned out to be highly effective (if boring, I'd presume, and they probably didn't ride too well with all that heavy metal hanging up high). Most started going into mothballs or the reserves during the mid-1960's when the Navy cut back it's radar picket program, although several ships saw extensive service off Vietnam as part of Operation Market Time, performing coastal surveillance and interdiction. One of the DER's ended up with the Tunisian Navy, while another went to the South Vietnamese Navy. It escaped in 1975 and later served with the Philippine Navy.

In June 1954 the ship was moved the Philadelphia Naval Shipyard, fitted out with the latest equipment, redesignated a Radar Picket Ship, DER-133, in August 1954 and recommissioned 15 March 1955. After refresher training and shakedown Pillsbury sailed for Newport R.I. to assume her duties as a Radar Guardship acting as an element of protective radar screen around the United States. During 1958 Pillsbury Made 7 picket patrols on the Atlantic Barrier, five trips to Argentia, Newfoundland and one trip to Summerside, Prince Edward Island.She was decommissioned 20 June 1960,and was struck from the Naval Vessel Register 1 July 1965, and sold for scrapping to Boston Metals Co., Baltimore, Md in 1966. Pillsbury recieved five battle staes for World War II service.