War may be good for business, at least the cable TV business. Local cable television operators said last week that installation orders were up dramatically in the two days following the first outbreak of fighting in the Persian Gulf.

Nevertheless, the cable companies couldn't help priming the pump just a little bit. Last Friday, the Washington Cable Council, a cooperative owned by local systems, began running radio ads offering free or reduced-price hookups to entice new subscribers.

The offer, according to the ad, is "part of our commitment to our communities during this troubled time. Access to vital news sources like CNN or C-SPAN during the Persian Gulf crisis is important to those with a need to know."

The ad concludes with a special 800 number and the exhortation, "Contact your local cable company for more details on this installation offer."

A spokesman for Cable News Network said the network was not aware of the ad. CNN, like many other advertisers, pulled its self-promotions from newspapers after war broke out to avoid the perception that it was exploiting the conflict, she said.

John Eddy, president of the cable franchise in Montgomery County, which is owned by Hauser Communications of New York, said the ad was run simply in response to public demand.

The cable council, he said, "tried to construct something close to statement more than anything else. No one in the cable industry is insensitive to the fact that this is a tough time for our country."