so ive been fighting this thing for about two weeks now and im at the point where im just gonna post about it and see if anyone has had the same deal. i put up a 7 element yagi for 2m, cheap one off amazon but the reviews were decent and the construction seemed fine when i checked it. mounted it on a push-up pole about 18 feet up, pointed roughly east because thats where most of my activity is.

the problem is my SWR is reading like 1.8 to 2.1 depending on where in the band i am. on 144.200 its a bit better but still not great. i ran about 35 feet of LMR-240 from the feedpoint down to the shack and im using a PL-259 that i soldered myself. the antenna is supposed to be fed directly with 50 ohm coax no matching needed according to the instructions but something is clearly off.

a buddy told me coax length can cause weird readings on VHF but i thought that was more of a myth. is that actually a thing or am i looking at a connector issue or maybe the antenna itself is just garbage. my radio is a Kenwood TM-V71A if that matters at all.

coax length can absolutely affect what your meter sees on VHF if there's any mismatch at the antenna end, it kind of transforms the impedance as you go down the line so depending on the electrical length of the coax you could be seeing something totally different at the radio than what's actually happening at the feedpoint. it's not a myth, it's just not usually a big deal if your antenna is well matched to begin with.

honestly my first suspect would be that PL-259. VHF is pretty unforgiving with connector issues and 35 feet of LMR-240 isnt gonna hide a bad solder joint. if you have an analyzer, try measuring right at the antenna feedpoint with a short pigtail. if the SWR cleans up there then you know its either the coax or the connector. if its still bad right at the antenna then the antenna or its dipole element spacing is the issue. those cheap yagis sometimes have the driven element cut way off.

yeah the connector thing is real, ive ruined a few measurements chasing ghosts that turned out to be a cold solder joint on a pl-259. the other thing i'd check is whether the boom is acting as part of the antenna -- on some of those no-name yagis the driven element insulation from the boom is basically nonexistent and you end up with the boom getting into the act and messing everything up. try clamping a few ferrite beads on the coax right at the feedpoint to see if it makes any difference, sometimes that clears it right up if your coax shield is carrying common mode current back into the picture.