George: Article 820 covers coax installation but has nothing about min burial depths. I am tempted to say table 300.5 column 1 (2005 nec). This is a good question ,around here the burial depths average 2- 4" for the local cable co. Ron
Didn't we just answer this question a little while back? The NEC doesn't cover this, I normally use UF depths while the cable guys will just make a slit with a lawn edger and stomp the cable into it. Of course they couldn't care less when it fails.
Make sure you use flooded cable for direct burial or pulled through pipe underground, not regular cable.
Hal- It might have been on this forum before, if it was I missed it. And, since you have a handle on telecom stuff (per your bio) what is "flooded cable"?
George, "Flooded" is the trade name for coax cable which is rated for direct burial. It has a grease of sorts under the jacket to prevent moisture from migrating.