So ive been running a Diamond X510 on the roof for a couple years now and its been fine for local stuff on 2m and 70cm, decent gain, no complaints really. But lately im noticing the 70cm side just doesnt reach the repeater about 22 miles out as reliably as id like, especially when the weather does weird stuff. Somebody at the club suggested just throwing a yagi up there pointed at that repeater since its the main one i care about on that band anyway.

The thing is im not sure its worth the trade off. Right now the collinear covers everything in all directions which is nice for simplex calling around and hitting different machines. If i put a yagi up for that one repeater im basically committing to a fixed path and losing the omni coverage. Unless i do both antennas which means another feedline run and honestly my coax situation on the roof is already kind of a mess.

Has anyone actually switched from a collinear to a dedicated yagi for a single path like this and found it worth it, or did you end up missing the omni too much and putting the collinear back up?

ran into the exact same thing a few years back trying to hit a 440 repeater about 18 miles out through some terrain. ended up just adding a cheap 7 element yagi on a second run of LMR400 and left the collinear in place. yeah it was another cable but once you do it its done and you stop thinking about it. the gain difference on 70cm from even a modest yagi pointed at a fixed path is pretty noticeable, especially if theres any hills or buildings in the way. i wouldnt pull the collinear down though, just run both if you can stomach the extra feedline.

the one thing id say is make sure youre not losing all your gain back in crappy coax. if youre running RG8X up to the roof on 70cm youre already giving up a chunk before the signal even gets to the antenna.

Honestly for a fixed path to one repeater a yagi makes a lot of sense. I did this for 2 meters years ago when I was trying to hit a machine on the other side of a ridge and the difference was not subtle. Even a modest 5 or 6 element yagi on 70cm is going to put several dB in the right direction and thats real usable difference not just numbers on paper.

The omni coverage thing is a valid concern but think about how often you actually use the collinear in directions other than toward that main repeater. If the answer is not that often, maybe the yagi is just the right tool. You could always keep the collinear hooked to a handheld or secondary radio if you really want to monitor around while the yagi is on your main rig.