What recorder are you using? It does sound more like a cable or connector issue. You might do some playing around with your recorder as well. I had a similar issue a while back. It turned out to be my recorder (Olympus LS-10) and the level wheel. I spent a lot of time looking at my mics, cables, connectors, preamp, etc.
I finally was able to recreate the problem in a certain range of gain on the level wheel, it would intermittently drop out completely or get very low or crackly when I adjusted the gain through that range. With it cranked up above 8 or so or down below 5, it would be fine, but in the 5 to 8 range it would drop out intermittently.
Something else to try or look at, anyway.