Today I completed the design of a new "front-end" for my tests on 8.76kHz when using earth electrodes as the RX antenna. Up to now I've used an 80cm loop/preamp at the far end of the test, usually with the loop on the ground for maximum signal pick-up. Now I want to compare results with an electrode pair antenna at the RX, laid across the road to form a pickup loop within the ground around any buried pipework and cables. The electrode pair is about 30-100 ohms, so I needed a low input impedance. I decided on a grounded gate FET amplifier with a simple LC tank circuit in the drain tuned to 8.76kHz fed via an emitter follower into the PC sound card. It has sufficient selectivity to reject 50Hz and lower harmonics and reject the stronger VLF and LF stations which could cause intermod and overload. I've also added a small LC lowpass filter on the input to the FET. This will be field tested at a site 5.3kms from the home QTH as soon as the weather improves: it is currently below freezing day and night!