I’ve been making a lot of RF cables during the past year, and as a part of that I had to come up with a way of testing them. The way I used to do it in the beginning was by using just the multi-meter probes, but as you can see in the video it can be a bit fiddly. I then came up with the idea of getting an adaptor to go from the banana plugs that the multi-meter uses to a BNC outlet. The reason I went for BNC is one of availability, oscilloscopes uses BNC to attach probe wires and most other lab devices use either BNC or banana plugs for inputs and outputs. As such, people make ready available adaptors to go from BNC to banana plugs. BNC is also something of a universal coaxial connector, so you can get adaptors to go from BNC to just about any other RF connector on the market.
The equipment I use is the following;
Assorted BNC to SMA/N/TNC adaptors
Now, that’s what I used, however, the type of multi-meter is entirely up to you, since we’re measuring resistance and nothing else, any multi-meter that works is enough. The multi-meter doesn’t even have to be very accurate, as we’re not interested in the absolute value, just that we have infinite resistance when first connected, and near zero resistance when we short out the other end of the cable under test.
Other articles in the series: