JOHN,

# 1 - Try a simple C-L-C "Matcher" between the Antenna
feed-in-line and the Antenna Input of your Receivers.

# 2 - Ensure that the Matcher is very well Grounded.

-or- # 3 - Place a Magnetic Long Wire Balun (MLB) -type-
Matching Transformer {actually an UnUn} at the point the
Long Wire Antenna Element meets the House and use a
50 Ohm Coax Cable from the MLB down to your Receivers.
Ensure that the Coax Cable is very well Grounded at the
Receivers.

hope this helps - iane ~ RHF