l would strong suggest using a coax which has a non-contaminating
jacket. Normal PVC jacket's plastisizers leach into the dialectric over
time and increase attenuation. There are a number of direct-bury types
of coax available, including RG-213 which would be overkill for use
with only a receiving antenna. You can e-mail directly, and I will
give you some suggestions. Remove the NO SPAM from my address.

Don Allen
e-mail: