Tonight, in an apartment on the outskirts of Moscow, Anatoly Scharansky's family gathered for the phone call from Israel they have been waiting for since 1973.

The call from Scharansky and his wife Avital was to be their proof that, after 12 years, nine spent in prison or camps, his ordeal had come to an end.

His mother, Ida Milgrom, a tiny, 77-year-old economist, already had greeted the news of her son's release with an uncharacteristic outburst of emotion.

As he crossed the Glienicke Bridge in Berlin, she was in a friend's apartment, surrounded by reporters and cameras. When the news was phoned in by a western correspondent, she burst into uncontrollable sobs.

To the reporters present, she said through her tears, "Anatoly is free. Lord God above, Anatoly is free. Before I used to only read it on the appeals -- 'Free Anatoly Scharansky.' Now I am at peace; he will be in his own country with his wife."

As the day wore on and Scharansky made his way across West Germany and on to Tel Aviv, his brother Leonid, 39, was left feeling dazed.

"I don't feel relief," he said in an interview in the early evening. "Maybe because I have been struggling for so long, like a boxer in the ring. I am happy, but I don't feel that it has ended, because it has gone on for such a long time."

Leonid Scharansky had just been to Moscow's central telephone exchange to send two telegrams on behalf of his mother, one to President Reagan and one to Soviet leader Mikhail Gorbachev, thanking them for their "good will and efforts in freeing my son."

He said he sent one to Gorbachev because the new Communist Party general secretary had not been in power when the Scharansky case began. "He is not responsible for what happened to my brother," said Leonid. "If it had been the others -- Brezhnev, Andropov -- then we would not have sent it." He was referring to former presidents Leonid Brezhnev and Yuri Andropov.

The day of the exchange at Glienicke Bridge in Berlin began here with high hopes. But the hopes were tinged with the familiar dread that despite all the official confirmations, everything could fall through at the last moment.

Now that Anatoly, 38, has joined his wife in Israel, the Scharansky family has a new set of worries. Milgrom and her son Leonid will go to the Supreme Soviet Wednesday to make a formal application to join Anatoly in emigration.

A report carried in the West German newspaper Bild this week had said that the deal to free Scharansky also involved permission for his mother to emigrate. But according to Leonid, the family will only leave the Soviet Union if all its members -- including his own wife and two sons, aged 14 years and 8 months -- can leave together.

"I shall apply," he said, "but I am not sure they will let me out. It took my brother more than 12 years to get out."

How Anatoly Scharansky came to be a Soviet dissident, jailed on charges of treason and freed in exchange for Communist agents, is a story that tracks the history of twin movements here, one involving human rights and the other Jewish emigration.

In 1973, Scharansky -- a bright young mathematician and chess master with a job programming computers -- was a "refusednik," as persons denied permission to emigrate to Israel are called. He was denied again in 1974, after trying to join his wife, whose visa had been issued one day after their wedding.

The refusals put him in touch with the world of Jewish activists and fellow refusedniks. From there, Scharansky gradually joined ranks with activists involved in broader human rights efforts: he eventually became a member of the group formed to monitor the 1975 Helsinki accords on East-West cooperation in Europe.

A fluent English-speaker with an irreverent and engaging style, Scharansky soon became spokesman and interpreter for various Soviet dissidents, including Nobel Peace Prize-winner Andrei Sakharov.

In that capacity, he became well known among western correspondents and diplomats. In March 1977, those connections provided the backdrop for an attack on Scharansky in the Soviet press, followed in less than two weeks by his arrest on charges of espionage and treason.

Scharansky's trial in 1978 was considered a turning point in the crackdown on the fragile dissident movement. The seriousness of the alleged crime and the length of the sentence -- 13 years -- served as warning signals to all activists. A vigorous press campaign, equating Jewish activism with treason, only underscored the point.

But the notoriety of the Scharansky case cut both ways: While the Soviet press was making its point, western groups took up the cause, making Scharansky one of the most prominent names in the list of Soviet human rights cases.

The activities of his wife Avital abroad and of his mother and brother here helped to keep the case in the public eye. Scharansky went on a 110-day hunger strike in 1980 to protest interception of his correspondence.

He originally was meant to serve three years in prison and 10 years in camp, but the prison sentence was lengthened after he was accused of being a bad prisoner.

While Scharansky was imprisoned, his father -- a Communist Party member who had worked as a journalist in the coal fields of the Ukraine -- died. His mother and brother saw him six times in nine years, four times for two hours each.

Now Leonid Scharansky is left to wonder when he will see his brother again. "I hope," he said today. "We are used to hoping."