Old timer told me I was running coax too tight and making the signal bounce, so now I leave a little sag in every drop.

After I started leaving 2 inches of slack at every clip, my return loss numbers went from -18 dB to -28 dB, has anyone else seen that big a jump from just changing tension?

3 comments

3 Comments

knight.mason22d ago

I read somewhere that cable tension actually changes the dielectric spacing inside the coax, which would explain why loosening it drops return loss that much. You tested that same brand cable before and after?

hugo82522d ago

Whoa, wait. You're telling me the physical tension of the cable is actually squishing the foam inside? That's wild. I always figured it was all about the connector quality or the braid. @knight.mason, I've gotta admit I never even thought to check for that. I've used that brand for years and never had an issue, but now I'm wondering if I've been cranking them down too tight this whole time. Guess I'll be backing them off a quarter turn from now on.

rodriguez.diana19d ago

The quarter turn trick is huge, I started doing it after a buddy showed me his VNA readings. Foam core cables especially hate being torqued like they're lug nuts on a truck. Take it from someone who's killed a few hundred feet of LMR-400 by being too aggressive with the wrench.