Watching new guys skip the bonding test on coax cables

I was helping a trainee in Long Beach last month and he swore his cable was fine without checking continuity through the shield. 5 minutes later we found a 3 ohm reading that would have killed the signal on a 737 antenna. Why do folks think a visual check is good enough for RF work?

3 comments

3 Comments

carr.abby13d ago

Stopped me cold when you said 3 ohms. I mean, that's basically a dead short in the RF world, especially at the frequencies we're talking about on a 737 antenna. I've seen guys pass a basic DC continuity check but skip the shield bond test and end up with a perfectly useless install. A visual check is just asking for trouble, like trusting a used car salesman's handshake.

colethomas13d ago

Wait, has anyone actually seen one of those installs where the bond measurement looked fine on paper but failed under real load? I swear @carr.abby just reminded me of this job I walked into once where a guy had used a tarnished star washer and thought it was fine cause it tightened down. The whole antenna setup was passing DC checks but the RF was getting killed by that one bad connection. It took us forever to track it down cause the visual check looked textbook. I still think about that washer every time I see someone skip the full bond test.

fiona_hunt7113d ago

Hold up though, has anyone checked what happens with those cheap digital multimeters when you switch between the resistance ranges? I had a meter that would show a solid bond at 200 ohms but would read totally different at the 20 ohm setting, and that little trap has wasted more hours of my life than I wanna admit. Most guys just grab whatever meter is nearby and trust it without testing the tester first.