Keeping in touch with high-school boarders

When a ninth-grader packs off to boarding school for the first long stint away from home, the transition can be challenging for both the student and the family left behind. Our daughter's departure for high school 2,000 miles away left an unsettling quiet on the home front. How are we to maintain our sense of family, our day-to-day sharing, that keeps us all in touch with one another?

Recalling my first quarter of college, which was my initial flight from the family nest, I knew the mailbox was my strongest link with home. My mother wrote to me almost daily the entire first year of college. Her letters were filled with anecdotes about my family, the weather, and other daily events that in themselves did not make headlines, but which together imparted the flavor of home. While I do not promise a daily letter to my daughter, I do look forward to carrying on this family tradition of letter writing.

Letters are a satisfying and permanent link to home, messages that can be read and reread, but there is an additional personal touch that can be shared: phone calls. The spontaneity of laughter, questions that can be answered quickly , and the simple joy of the immediacy of communication in a phone conversation can be an anticipated highlight of the week. If you plan for it, you can take advantage of the cheapest phone rates, at night or on the weekends. Ask your teen-ager to tell you when his schedule permits receiving calls during the hours with low rates.

Some families enjoy exchanging tape cassettes in which they have recorded a variety of events and voices. This is especially appealing to younger siblings who are not yet able to write letters on their own.

Most families have at least one camera buff who enjoys snapping informal shots at family gatherings. Your teen-ager probably has a bulletin board in his or her dorm room that would be brightened by faces and places from home.

There are countless ways to bridge the inevitable gaps that families feel in the early months of separation. Moments of loneliness can be turned into joyful opportunities for sharing your love and care. Some of the following ideas might serve as a springboard for ways you can expand your sense of home and family with your teen-ager:

* Subscribe to one of his favorite magazines. Have it sent to him at school.

* Give his school address to relatives and friends.

* Ask your florist to recommend a low-maintenance plant that will brighten a dorm room. Have it sent to him.

* Order some personalized stationery or address labels with your teen-ager's school address.

* Clip his favorite cartoons and columns from the local newspaper. Send them once a week.

* Send a ''care'' package of homemade goodies for your teen-ager to share with dorm mates. (Check first for school policy on food in dorms.)

* Remember to say ''I love you'' frequently.

The channels of communication you establish with your teen-ager today will bring you long-term rewards. And cheers. They will be home for the holidays before you know it.

P.S. My mother is still my most faithful pen pal. Her letters have followed me from coast to coast for 20 years. That is some legacy to pass along to my daughter!