President Reagan will try to build the Navy a skeleton version of the radio grid it is seeking in upper Michigan and Wisconsin to beam messages to submarines patrolling the depths, the Pentagon announced yesterday. The mini-grid would cost $230 million and go into service in 1985.

Since the 1960s, the Navy has been trying to find a home for a communications system powerful enough to penetrate the ocean so submarines would not have to continue rising near the surface to receive electronic messages. The deeper a submarine, the less chance it may be detected.

Wisconsin was the Navy's first choice for the grid, partly because the northern part of the state includes a layer of rock that reflects radio waves to help them penetrate the sea.

The original plan called for the burying of 4,000 miles of cable in the forests near a town called Clam Lake. Over this grid, called Sanguine, a president could have sent a doomsday message to submarines to fire missiles at the Soviet Union.

But Wisconsin citizens, many of them mobilized by environmental groups, rebelled against Sanguine for fear that its powerful radio beams would harm them, electrocute earthworms, provoke miscarriages in cows and ruin television reception. The Navy commissioned several studies that concluded no such things would happen.

Nevertheless, the protests continued, prompting then-Defense Secretary Melvin R. Laird, a Wisconsinite, to order Sanguine out of the state as one of his last acts at the Pentagon in 1973.

The Navy then tried to sell Sanguine to Texas, only to have hunters around the chosen site do everything but fire their rifles at an admiral trying to assure them that no harm would come to the surroundings, including the deer.

So the Navy went back north to Michigan's Upper Peninsula where it built a small experimental grid at the K.I. Sawyer Air Force Base. Again, protests and environmental alarms broke out.

During his 1976 presidential campaign, Jimmy Carter promised he would not force the grid--whose name went from Sanguine to Seafarer to ELF, for extremely low frequency--upon the people of Michigan.

A Navy plan to connect the Wisconsin and Michigan test sites was never carried out during the Carter administration, even though the military warned that better submarine communications were critical.

Reagan's mini-ELF, recommended by Defense Secretary Caspar W. Weinberger, is a skeleton of the 4,000-mile Sanguine. It would consist of 28 miles of cable at Clam Lake and 56 miles more around Sawyer Air Force Base in Michigan.

Messages sent to submarines over this comparatively small network would be short and slow, compared by the Navy to flag hoist signals sent by one ship to another.

Presidential missile-firing orders would not be sent over this mini-ELF. The closest thing to those would be coded signals for submarines to rise near the sea's surface to receive instructions from other sources.

One such source are Navy C130 planes that trail long sending antennas. They are part of the fleet called TACAMO (Take Charge and Move Out).

Capt. Daniel E. Donovan, deputy director of naval communications, conceded in a Pentagon briefing yesterday that Reagan's ELF is much less capable than the system the submariners originally sought. But, he said, "some system is better than none at all."

Reducing the amount of time submarines would have to stay near the surface to receive messages would reduce their vulnerability proportionally, he said.

Donovan also recommended that laser beams to penetrate the depths be pursued at the same time the mini-ELF is under construction. One early political return indicated that even this mini-ELF will run into trouble in Congress.

Said Sen. Carl Levin (D-Mich.) yesterday about Reagan's proposal:

"ELF is an outmoded and ineffective scheme . . . . I will continue to try to block the wasteful expenditure of public funds" for it.