so ive been running a diamond X50 on my roof for a couple years now and it works fine for the 147 repeater about 18 miles out, but i keep dropping into the noise when conditions get a bit rough or if theres weather. a buddy of mine says just put up a yagi and point it at the repeater but that feels like overkill for just working local. the X50 is up about 25 feet on a pushup mast.

the repeater is roughly east-northeast from my QTH. i dont really need omnidirectional coverage that badly — i mostly use that one repeater and maybe one other that's more or less in the same direction. so part of me is thinking maybe a small 5 or 6 element yagi on 2m would actually solve the problem and then some. but then i'd need a rotor if i ever want to work anything else, or i just fix mount it aimed at the repeater.

has anyone gone through this same thing? curious what people actually found made the difference, whether it was antenna gain, feedline, height, whatever. im running about 40 feet of LMR-400 to the radio right now.

honestly the feedline situation sounds fine so i'd look at the antenna height before anything else. 25 feet might not be clearing whatever is between you and that repeater. a collinear like the X50 has pretty compressed vertical pattern too which helps on flat terrain but if there's any terrain in the way it can actually work against you depending on the angle.

a fixed yagi aimed NNE is really not a bad solution if that's where 90% of your activity is. i ran a 7 element M2 aimed at a hilltop repeater for like 3 years with no rotor and never had a problem. just gotta accept you're not going to swing it around on a whim. the gain difference going from the X50 to even a modest yagi is substantial enough that you'd probably notice it immediately on that path.

what's the terrain like between you and the repeater? that matters way more than people give it credit for. i went through the exact same decision last spring and ended up just going higher with the collinear first — got the mast up to about 35 feet and the difference was noticeable enough that i didnt bother with the yagi. granted my path is pretty clean. if you've got a ridge or buildings in the way a yagi probably wont save you either unless you can get above the obstruction.