I’ll pile on and recommend this as well. The same device can also do time-domain reflectometry (which will tell you where there’s a break in the line - great for problems with buried or hidden cables). And you can also do signal-loss analysis… I had water leak THROUGH a cable - it got in by the antenna, and was dripping on my freaking desk inside. I was about to throw out the cable, but I decided to test it for loss while wet (… it was bad) and then put it in a vacuum oven for a few days and test it again (… it came back!). I think just with that one run of cable that little thing paid for itself!
I’ll pile on and recommend this as well. The same device can also do time-domain reflectometry (which will tell you where there’s a break in the line - great for problems with buried or hidden cables). And you can also do signal-loss analysis… I had water leak THROUGH a cable - it got in by the antenna, and was dripping on my freaking desk inside. I was about to throw out the cable, but I decided to test it for loss while wet (… it was bad) and then put it in a vacuum oven for a few days and test it again (… it came back!). I think just with that one run of cable that little thing paid for itself!