I have a situation similar to this: Testing for 'Bad' Coax . In addition to checking for DC continuity or shorts, here was my test method:
My 50Ω dummy load (Elecraft DL1) has a diode and capacitor test point so that you can use a volt meter to measure power at the dummy load.
I connected the dummy load to the rig (transmitting a carrier at 144 MHz) and measured the voltage (using a Fluke 75III DVM), then connected the cable under test between the rig and the dummy load and measured the voltage again. With just the dummy load, I measured 6.2V at the test point (which calculates to the expected 1.6W).
The first cable was short (<5m) and it measured 5.4V (i.e., a significant loss); other cables (all of them RG-8 type, and all <20m long) measured under 1V.
- Was that a valid test?
- Am I correct that these cables were junk?