Harry E. Yarnell was equipped with RIM-2 Terrier surface-to-air missile launching rails both fore and aft and ASROC anti-submarine missiles, as well as more conventional torpedo tubes and guns.
The new ship was fitted out at Boston and began sea trials.
While out on trials, Yarnell was diverted on 10 April 1963 to search for USS Thresher (SSN-593), the nuclear submarine later found on the bottom some 8,000 feet down.
Quartering the area where the sub was last reported, the guided missile frigate found an oil slick and some debris but could not contact the lost submarine.

On her way to her new home base, Naval Station Norfolk, on 23 April, Harry E. Yarnell passed and photographed several Soviet "merchant" ships.
The next few months were spent conducting training for shakedown and missile qualification.
Designated to carry out standardization trials for her class as well as special acoustical tests, Yarnell spent 28 October–26 November in the Caribbean operating out of Guantanamo Bay and then returned to Norfolk.

Yarnell continued operating in the Virginia Capes area and the Caribbean until departing from Norfolk on 8 September 1964 for her first Atlantic crossing.
NATO ASW exercises en route took the guided missile frigate far north, and she crossed the Arctic circle on 21 September.
She visited Amsterdam en route to the Mediterranean, where she remained until returning to Norfolk in February 1965.

On her next Mediterranean deployment, which began 8 October, she transited the Dardanelles on 3 January 1966 and entered the Black Sea to operate close to the Soviet Union before returning to Norfolk in March.
After NATO exercises in the North Atlantic, Harry E. Yarnell received the battle efficiency "E" for the preceding year.
She also won the 1966 Marjorie Sterrett Battleship Fund Award for the Atlantic Fleet.

Operations in the Gulf of Mexico and Caribbean brought the ship and her crew to a high degree of readiness before she sailed for her 3rd Mediterranean deployment early in 1967.
She cruised the Mediterranean until returning to Norfolk in May. At mid-year she operated in the North Atlantic.

After the upgrade in Bath, Maine, in 1969, the Yarnell made her way to Boston Naval Shipyard.
 The Yarnell was given a new crew and recommissioned for service in Boston.
The Yarnell was then assigned to Naval Station Newport.
A year of testing all the new systems and the Yarnell set sail in July, 1970 on a UNITAS cruise for exercises with the naval forces of South American countries.
 Following departure from Newport and an overnight visit at Dam Neck, VA, Yarnell sailed to San Juan, Puerto Rico to pick up the admiral for the cruise.
 The Yarnell visited Caracas, Venezuela; and Salvador, Rio de Janeiro (twice) and São Paulo, Brazil.
A scheduled visit to Montevideo, Uruguay was cancelled due to political activity there, so Yarnell returned to Rio de Janeiro for a second visit.
 Following a stop in Comodoro Rivadavia, Argentina to take on supplies, Yarnell proceeded through the Magellan Straits and the Chilean Waterway into the Pacific Ocean, where stops were made in Chile, Peru, Ecuador, and Panama before going through the Panama Canal and returning to Newport via San Juan and St. Thomas, U.S. Virgin Islands.

In late 1972, the Yarnell was again deployed to the Mediterranean.
 On the way across the Atlantic a helicopter from a Russian cruiser flew around the Yarnell taking many photographs.
 The Yarnell was ordered to accompany the Russia submarines from the Strait of Gibraltar to the Black Sea.
 Yarnell made port visits at Naples, Genoa, and Venice, Italy; Nice, France; Mallorca, Valencia and Barcelona, Spain; and Athens, Corfu, Rhodes, and Kavalla; Greece.

Yarnell returned to the Mediterranean in August 1973.
En route she visited Lisbon, Portugal, then took part in Exercise Quickshave off the coasts of France, England and Portugal, followed by turnover in Rota with the USS Dale.
Yarnell then deployed to La Palma, followed by Western Med operations as a picket with a short return afterward, to Palma.
Group Operations off Crete along wit
Harry E. Yarnell was equipped with RIM-2 Terrier surface-to-air missile launching rails both fore and aft and ASROC anti-submarine missiles, as well as more conventional torpedo tubes and guns. The new ship was fitted out at Boston and began sea trials. While out on trials, Yarnell was diverted on 10 April 1963 to search for USS Thresher (SSN-593), the nuclear submarine later found on the bottom some 8,000 feet down. Quartering the area where the sub was last reported, the guided missile frigate found an oil slick and some debris but could not contact the lost submarine.
On her way to her new home base, Naval Station Norfolk, on 23 April, Harry E. Yarnell passed and photographed several Soviet "merchant" ships. The next few months were spent conducting training for shakedown and missile qualification. Designated to carry out standardization trials for her class as well as special acoustical tests, Yarnell spent 28 October–26 November in the Caribbean operating out of Guantanamo Bay and then returned to Norfolk.
Yarnell continued operating in the Virginia Capes area and the Caribbean until departing from Norfolk on 8 September 1964 for her first Atlantic crossing. NATO ASW exercises en route took the guided missile frigate far north, and she crossed the Arctic circle on 21 September. She visited Amsterdam en route to the Mediterranean, where she remained until returning to Norfolk in February 1965.
On her next Mediterranean deployment, which began 8 October, she transited the Dardanelles on 3 January 1966 and entered the Black Sea to operate close to the Soviet Union before returning to Norfolk in March. After NATO exercises in the North Atlantic, Harry E. Yarnell received the battle efficiency "E" for the preceding year. She also won the 1966 Marjorie Sterrett Battleship Fund Award for the Atlantic Fleet.
Operations in the Gulf of Mexico and Caribbean brought the ship and her crew to a high degree of readiness before she sailed for her 3rd Mediterranean deployment early in 1967. She cruised the Mediterranean until returning to Norfolk in May. At mid-year she operated in the North Atlantic.
After the upgrade in Bath, Maine, in 1969, the Yarnell made her way to Boston Naval Shipyard.  The Yarnell was given a new crew and recommissioned for service in Boston. The Yarnell was then assigned to Naval Station Newport. A year of testing all the new systems and the Yarnell set sail in July, 1970 on a UNITAS cruise for exercises with the naval forces of South American countries.  Following departure from Newport and an overnight visit at Dam Neck, VA, Yarnell sailed to San Juan, Puerto Rico to pick up the admiral for the cruise.  The Yarnell visited Caracas, Venezuela; and Salvador, Rio de Janeiro (twice) and São Paulo, Brazil. A scheduled visit to Montevideo, Uruguay was cancelled due to political activity there, so Yarnell returned to Rio de Janeiro for a second visit.  Following a stop in Comodoro Rivadavia, Argentina to take on supplies, Yarnell proceeded through the Magellan Straits and the Chilean Waterway into the Pacific Ocean, where stops were made in Chile, Peru, Ecuador, and Panama before going through the Panama Canal and returning to Newport via San Juan and St. Thomas, U.S. Virgin Islands.
In late 1972, the Yarnell was again deployed to the Mediterranean.  On the way across the Atlantic a helicopter from a Russian cruiser flew around the Yarnell taking many photographs.  The Yarnell was ordered to accompany the Russia submarines from the Strait of Gibraltar to the Black Sea.  Yarnell made port visits at Naples, Genoa, and Venice, Italy; Nice, France; Mallorca, Valencia and Barcelona, Spain; and Athens, Corfu, Rhodes, and Kavalla; Greece.
Yarnell returned to the Mediterranean in August 1973. En route she visited Lisbon, Portugal, then took part in Exercise Quickshave off the coasts of France, England and Portugal, followed by turnover in Rota with the USS Dale. Yarnell then deployed to La Palma, followed by Western Med operations as a picket with a short return afterward, to Palma. Group Operations off Crete along wit
USS Harry E. Yarnell