Alan, all:
I suspect that you need to isolate the loop feed with a small transformer.
It is possible that
the feed from the loop is acting as a wire aerial and is conducting TV RFI
and noises from the
house *back to the loop*.
Surprising how few understand the concept of the RFI actually going from the
receiver back to the antenna site. This applies to E-probe antennas as well.
The typical house/apartment is a mad jumble of LF RFI having both E and H
field components. The proper RF return for remote LF antennas is the ground
immediately under the antenna - not the safety (green wire) ground in the
shack that connects to the chassis of the receiver. The isolation
transformer installed in the coax lead-in offers the only way to sever these
totally different grounds. In severe cases one is needed both at the
receiver and at the antenna since a floating coax shield can pick up noise
before it leaves the vicinity of the shack.
BTW, an isolation transformed can be as simple as two 15-turn windings of
#22 to #28 wire on a common 3/4"dia X 1" ferrite RFI bead found on computer
power cords, monitor cables, communications cables, etc.
Bill A
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