Learned the hard way about cheap coax cables

Bought a 50-foot RG58 cable off eBay for $12 last month. First flight test showed intermittent signal loss on the VOR receiver. Spent 3 hours troubleshooting before I realized the cable had crap shielding and high resistance. Has anyone else burned time on bargain-bin cables from online sellers?

3 comments

3 Comments

chen.adam1mo ago

Did you check the DC resistance before flying or just assume it worked?

the_wren1mo ago

I had a 2200mAh 4S pack last year that read 18 ohms on one cell right before a flight. @chen.adam you're totally right, nobody checks DC resistance until something goes wrong. That pack was still puffing a little but I figured it was fine since it charged up okay. Took it up about 30 seconds before the voltage sagged so bad the quad fell out of the sky. Now I check every new pack at least once before the maiden flight.

keith_rivera191mo ago

Wait, is checking DC resistance really that big of a deal or is this just one of those things people obsess over after one bad crash? I mean, I've had packs that were slightly puffy and they flew fine for like 20 more flights before I finally retired them. Not saying you're wrong (your story is rough, no doubt), but 18 ohms seems crazy high for a 4S pack that still charged balanced. Are you sure your meter wasn't giving a bad reading or the connectors had a loose connection? I feel like half the time these problems are from a bad solder joint on the plug, not the actual cells themselves.