You can build a model airplane out...

You can build a model airplane out of sticks and tissue for pennies, or you can spend $1,500 for a radio-controlled jet model that will streak across the sky at more than 100 m.p.h.

Both types of aircraft will be in evidence at the 15th annual International Modeler Show, which runs Friday through Sunday at the Pasadena Center.

The show also will include radio-controlled helicopters, an indoor pond with electric-powered boats, a G-scale train layout and an exhibit of quarter-scale race cars. Slow-moving model blimps and balloons will hover inside the building at 300 E. Green St., where more than 175 exhibitors will show new products.

Bill and Anita Northrop, the show organizers, said

past events have attracted as many as 15,000 to 20,000 visitors.

The Northrops started the shows as an outgrowth of magazines they published for model hobbyists. They have since sold the magazines to devote full time to trade shows, which they stage in Orlando, Fla. and Milwaukee, Wis., as well as Pasadena.

Bill Northrop, who started building model airplanes in the 1930s, said the hobby appeals to people who want a diversion where “you can get your mind off your work and be your own boss.”

It can be an all-consuming hobby, particularly for men, he said.

“There are model airplane widows just like golf widows,” he said.

Although the radio-controlled model industry is growing and producing more sophisticated products, Northrop said one problem is attracting younger enthusiasts.

Children have so many other interests these days, he said, that “it’s tough to get them into it.”

The Black Sheep Squadron model club from Burbank will show beginners how to build a basic model plane, which they can take home free.

The show will be open Friday morning to the model industry. The public will be admitted from 2 to 7 p.m. Friday, 10 a.m. to 6 p.m. Saturday and 10 a.m. to 5 p.m. Sunday. Admission is $5. Children under 6 will be admitted free.