BALTIMORE, FEB. 4 -- Two former executives of Nurad Inc., an antenna manufacturing firm here, were ordered imprisoned today after pleading guilty to falsifying records to conceal substandard production of radar-jamming devices designed for the Air Force F-16 fighter plane.

David Rider, 50, a former Nurad vice president, was sentenced to three years by U.S. District Judge Walter E. Black Jr. Rider pleaded guilty last August to two counts of making false statements that masked the failure of the antennae to meet U.S. performance specifications. Prosecutors said Rider is not likely to be considered for parole until he has served at least one year.

Bruce Kopp, 35, a former project engineer for Nurad, was sentenced to eight months in prison after pleading guilty to one count of making false statements. He is expected to serve his full term minus a possible short period of credit for good behavior in prison.

The F-16 is an all-weather fighter plane being used in the Persian Gulf War. The Nurad antennae, designed to jam radar of hostile aircraft and missiles, were never permanently installed in any F-16s, and shipment of the devices was suspended in 1988 after authorities were tipped to possible irregularities.

Prosecutors said the F-16s in the gulf war are equipped with other jamming devices.

In addition to Rider and Kopp, Nurad as a corporation pleaded guilty to falsifying test results on the antennae and was fined $500,000 on Jan. 24 by Black. Nurad, a subsidiary of New York-based Dover Corp., also agreed to pay $750,000 in settlement of a civil claim by the government.

The case grew out of a $4 million subcontract that Nurad won in 1985 to make 700 special antennae as part of an Airborne Self-Protection Jammer system for the F-16, manufactured by General Dynamics Corp.

Prosecutors said Nurad executives ordered technicians to alter testing procedures to generate documents that made the antennae appear to meet performance requirements.