IF YOU TUNE IN to "The 1940s Radio Hour" at the Round House Theater, be prepared to tune out some static and dead air.

Walton Jones' amiable environmental piece places us in the hubbub at run-down Manhattan radio station WOV, where they're preparing for and producing the Christmas 1942 variety broadcast. It's a sentimental look back at what in hindsight seems a simpler, sweeter time. As the "studio audience" we enter the station's daily life, with scurrying delivery boys and technicians, minor disasters and office romances patching in and unplugging. An actual one-hour "broadcast" is performed, with lots of old-timey commercials, schmaltzy messages to the boys "over there," and a lively radio serialization of "A Christmas Carol," complete with sound effects.

Music director Roy Barber has chosen the standard standards -- "Cattanooga Choo Choo," "Boogie Woogie Bugle Boy," etc., but they are manhandled by the five-piece band and the strained vocalizing of several principals. The ensemble singing is exceptional, though, rebuilding the period's unmistakable harmonies.

The real find here is young Tami Tappan as Connie, a teen singer. Tappan has grown markedly as a performer since last year, and has become a remarkably strong singer and dancer. She and tenor Brian Davis capture the '40s ballad sound and phrasing to perfection, and luckily they have a duet or two.

This "Radio Hour" had a successful run at Arena's Kreeger Theater before being transplanted to Broadway, where its cozy, busy ambience was lost in the larger house.

Richard Young has created a cluttered, careworn studio set, as lovingly detailed as a Norman Rockwell painting. And Round House's staging has the appropriate intimacy -- we're close enough to read the characters' mail. But it drags; the show feels much longer than its two hours.

Director Jim Humphrey strives for a beehive effect, but his efforts are undercut by the players, who are intent on calling attention to themselves. Given time, the Round House ensemble may settle into a more natural behind- the-scenes bustle.

THE 1940s RADIO HOUR -- At Round House Theater through June 2.