WP Aggregator Feed Limit

// Set custom number of posts for category feeds

function custom_category_feed_limit($query) {

    if ($query->is_feed() && $query->is_category()) {

        $query->set('posts_per_rss', 100);

	$query->set('nopaging', true);

    }

}

add_action('pre_get_posts', 'custom_category_feed_limit');