Summary: This eleven mile out and back hike starts at the Douglas trailhead, which begins at the end of Wildcat Mountain Road (paved the whole way) and traverses the ridge between Wildcat and Huckleberry. The hike climbs roughly 2800 feet with a quarter or so of up reserved for the return hike. The trailhead is popular but few people head up to Huckleberry and fewer still to the high point of the ridge. ATT cell service is non-existent, APRS works pretty well, and 2M contacts are fairly easy. I recommend doing Huckleberry first, which makes Wildcat an easy summit and the hike back the trailhead, relatively short.
TL;DR: Wildcat is a good "first" SOTA hike: relatively close to PDX, paved road the whole way, and a relatively short round trip hike without much steep. Doing the Huckleberry Wildcat traverse is more of a commitment. The hike is eleven miles of up and down (you will climb to 4400 feet three times, dropping down to 3800 feet in between) and there are some steep sections both out and back. Given the terrain, I recommend hiking to Huckleberry first and saving the short hike to Wildcat's summit for the return, as it is only two miles from the trailhead.
You will start at the Dougles (781) trailhead which travels up and around an old quarry, cutting across an abandoned road a couple of times before heading northeast and climbing the ridge to Wildcat. You will see the turn up to Wildcat about 2.2 miles into the hike. Keep going on 781 for another 1.2 miles (and a 400 foot descent) before turning northeast on Plaza (783). You'll drop another two hundred feet before beginning the climb up to Huckleberry. The hike from here has some steep sections, going up 500 feet or so.
The summit trail cuts off 783 about 0.2 miles before the summit. The tail is faint and sometimes brush-covered but easy to follow. The summit itself is small and covered with trees; getting a wire in the air would be easy-ish. I made 2M contacts into Portland and the gorge but did not set up HF gear. There was no ATT cell service; APRS digi echoes were plentiful. When you've had your fill of RF, pack up and head back the way you came.
Do some more up and down for about three miles before turning left on the short steep trail to Wildcat's summit (45° 17.6756' N, 122° 2.4762' W), where you will find a small, flat summit surrounded by trees. Getting a wire up is easy, as are 2M contacts. If you set up carefully, you will be in the shade, otherwise sunscreen is an excellent idea. The hike down to the trailhead is, yes, mostly down and only a little more than two miles. Qutie the relief after the previous nine miles!