[Andrew2]

Argus - surely any direct connection of a feeder to 'one side' of the loop would ruin the balance, spoil the null and bring about the 'antenna effect' in which the loop begins to act as just a random wire?
I still say a single-turn coupling loop (floating) fed with coax should be fine. A step-up ferrite transformer at the receiver may be necessary if the radio has a high input impedance.