Bonn — There are mixed signals coming over the Berlin Wall. The East Germans are raising part of the wall from 13 to 16 feet. At the same time, they are permitting mass emigration from East to West Germany for the first time since the wall was erected in 1961.
East Germany opened the flood gates on Feb. 18, without prior announcement or subsequent explanation. Since then, about 5,000 people have been allowed to leave the country for West Germany legally, often taking their furniture with them. That is 10 times the usual rate, and no one knows how long it will last.
West German leaders discuss the new situation in measured tones, trying to avoid gloating lest the Communists once more slam the door shut.
In his annual report to Parliament on the state of the nation March 15, West German Chancellor Helmut Kohl declared carefully that ''since my last report a year ago, inner-German relations have generally developed positively.''
But Mr. Kohl shares the general feeling that communist liberalization is in reaction to the Bonn government's decision in 1983 to guarantee a billion mark (about $385 million) commercial bank loan to East Germany - then, as now, short of hard currency to finance the purchase of Western capital goods.
No political conditions were expressly attached to Bonn's guarantee because, as one high government source put it, ''you can't buy the communists.''
But at the time, Kohl and his lieutenants all said they harbored ''certain expectations.''
''In approving the loan,'' Kohl told Parliament, ''the government sent a clear signal to the leaders of the (East) German Democratic Republic. . . . We maintain our security and alliance interests, but naturally are prepared to cooperate in the inner-German relationship.''
Business journalists at the Leipzig spring fair last week reported the East Germans now are looking for a number of additional but smaller Western loans.
Most Western leaders assume the communists are preparing the way to ask for those additional loans, and also improving the atmosphere in advance of East German President Erich Honecker's first visit to West Germany this fall. Honecker probably wants to be able to visit his hometown of Saarbrucken without provoking the ugly street protests that marked East German Prime Minister Willy Stoph's visit to Kassel 14 years ago.
This probably also explains why Honecker began last fall to dismantle the deadly booby-trapped shotguns mounted along several hundred kilometers of the East-West German frontier. These have been a sore point with the West Germans. Their removal will soothe a lot of tempers without actually making it any easier to cross the border without permission.
To underline the point that the communists still have no intention of permitting uncontrolled exchanges across the dividing line between the two German states, they last week began to build a new section of the wall near Berlin's Brandenburg Gate. The new section is higher than the old wall it apparently is to replace, making it more difficult for Germans even to look across at each other.