[RFI] Advice - CAT direct burial cable

[Gary Smith]

Now that my health is a bit better I am going to replace the CAT-5 
cable I have been using for 

1. A 350' run to my remote coax switch.

2. a 400' run to my HI-Z controller.

What I originally did 5 years ago was buy ribbon CAT-5, used for 
indoor installations and lay it on the ground to the remote Coax box 
and to the HI-Z. Leaves covered it and after a couple of years you 
can't see it. 

I am though having issues with RFI I haven't located yet and was 
thinking the parallel wires and not being burial wire may have some 
disadvantage under twisted pair, direct burial cable.

Most all of the CAT cable that's direct burial and with twisted pairs 
that I've looked at though use 24G copper clad aluminium wire. I'm at 
the edge of the ocean and don't know if copper clad aluminium is 
considered a good choice for this location. I'd think it probably is 
OK in that the aluminium is not exposed to the elements. Not sure how 
well copper clad aluminium solders either.

Opinions?

Thanks!

Gary
KA1J