More than 73,000 federal workers in hard-to-fill jobs will get "special" pay raises averaging 3 percent this month. The increases are supposed to make the government competitive with private firms.

Uncle Sam's special pay umbrella can extend worldwide to all the employes in an occupation, whether they work in Germantown, Md., or Germany, or the special rates may be limited geographically with surgical precision so that employes working on one side of the street sometimes get the raises and those a block away do not. Examples:In April, the government gave pay adjustments to 42,000 clericals here, the largest occupational group ever to receive the special raises. Their increases ranged from 2.6 percent to 23 percent. Employes who got them aren't included in the newest round of special rate raises.

This month's raise for some medical officers is worldwide, yet raises for certain GS 4 and 5 clerk-typists are limited to the Corps of Engineers employes in the Federal Center South building in Seattle. Clerk-typists in other agencies or other buildings there get no raise. Even more precise are the pay boundaries for certain GS 2 through 6 clericals on the West Coast. To be eligible for this month's special rate raise, employes must work in Los Angeles "within the area bounded by Manchester Avenue on the north, Crenshaw Boulevard on the east, Artesia Boulevard and Gould Avenue on the south and the Pacific Ocean on the west. Included are positions in the Defense Investigative Service, 15110 Atkinson Ave., Gardena, Calif., and Army Plant Representative Office-Hughes Helicopter (Culver City) and the Centers for Disease Control (other positions within the department of Health and Human Services are excluded)." Now that is spelling it out.

Locally, the October special rate increases will go to the following jobs:

Medical Officer, Series GS 602 (primary care): GS 11, $34,678 to $42,832; GS 12, $41,568 to $51,342; GS 13, $49,430 to $61,049; GS 14, $56,912 to $70,637; GS 15, $61,659 to $77,805 (but limited to the statutory rate of $72,500).

Medical Officer (nonclinical): GS 11, $32,934 to $41,088; GS 12, $39,471 to $49,245; GS 13, $48,162 to $59,781; GS 14, $53,917 to $67,642; GS 15, $58,135 to $72,500.

Medical Officer, other positions: GS 13, $46,471 to $58,090; GS 14, $51,865 to $65,590; GS 15, $57,418 to maximum of $72,500.

Metallurgist, Series GS 1321: GS 5, $18,364 to $22,603; GS 7, $22,747 to $27,994; GS 9, $25,689 to $32,115; GS 11, $28,489 to $36,409.

Computer Scientist, Series GS 1550, limited to positions in NASA, Defense, Commerce, HHS and Treasury: GS 9, $26,215 to $32,956.

Petroleum Engineer, Series GS 881: GS 5, $19,268 to $23,714; GS 7, $23,886 to $29,374; GS 9, $28,347 to $34,890; GS 11, $30,640 to $37,714.

Patent Examiner (engineering specializations only), Series GS 1224: GS 5, $19,268 to $23,714; GS 7, $23,866 to $29,374; GS 9, $25,454 to $32,195.

Therapeutic Radiological Technologist, Series GS 648: GS 8, $22,921 to $29,023.

Nurse, Series GS 610: GS 5, $19,268 to $23,714; GS 7, $20,806 to $26,314.

Nurse, Series GS 610 (critical care): GS 9, $24,705 to $31,446.

Nurse and psychiatric nurse (St. Elizabeths Hospital): GS 4, $16,055 to $20,033; GS 5, $17,614 to $22,060; GS 7, $20,605 to $26,113; GS 9, $23,725 to $30,466.

Professional Engineer: GS 9, $29,199 to $35,940; GS 11, $31,383 to $39,537; GS 12, $35,825 to $43,753.

Electrical Engineer: GS 9, $29,199 to $35,940; GS 11, $31,863 to $40,017; GS 12, $35,825 to $45,986.