That's great weekender. Sorry to hear the alarm didn't work first time. As well, the sound of the alarm is piercing on my receivers, and I assume that's what happened on yours, the coyote heard it and off it went. That's why I cut the speaker wire (actually DoubleUp did for me) and affixed a jack for a headphone or earbud.
One thing you might consider on the alarm is to do just that, cut the speaker wire, then wire in a 3.5mm female jack for a headphone. To have sound, there are lots of small speakers that have male jacks that would fit the receiver. You could plug it in for sound and then disconnect it quickly once a coyote is on the bait. Just a thought.
I have killed one coyote (head shot) with a .22 magnum at about 75 yards. I'm like you in that I don't feel very confident on body shots with that caliber, particularly at any great distance.
Looks like you have a lot of hogs down there too. That's great. Looks like it might be a bit messy getting the hogs out of there though.
UPDATE FOR DOUBLEUP: I've slept on it long enough and now have a offer to make. I will trade you (with a lot of reservation) one attack possum for one basic black, er I mean one classic black coyote. The only catch is you will have to come get the possum since he's too dangerous to transport via UPS or mail. Oh, and you could just bring that black coyote with you when you come and save me some postage, old buddy.
Here's a video of my attack possum in action. He's the real deal.
Click the on the photo to see the video.
Guys, you can tell the coyote hunting is very slow for DoubleUp and me
since we have to resort to such folly in order to keep some patience.