No problem, Glenn.The long wire used here about 80ft of wire between trees, at about 20ft off the ground. Nothing special there.
The optimisation for low frequency comes in where the down lead meets the coax.
If you have access, this was documented in The Lowdown... I will provide a reference shortly.
The antenna and ground leads are ere connected to the primary winding of a ferrite core transformer. Ground is provided by a spike at the feed point. Coax running back to the listening position is connected to the transformer secondary. The coax shield is not connected to the ground of the antenna circuit
The transformer was designed to ensure each winding has plenty of self inductance at LF (2-3 millihenry on the primary, IIRC). This does two things - it prevents the LF signals from the antenna simply sorting to ground, and for the coax, prevents the shorting of common mode noise onto the radio input. Keeping the antenna and coax grounds separate also is very important in preventing "house" noise from adding to the clean signal between antenna and ground rod. The transformer is (IIRC) 3:1 turns ratio, and wound on a cylindrical core ~3/4" long, of the type usually used for emi suppression on cables. It was chosen based on having a high permeability, so large inductance could be achieved with relatively few turns.
Further noise defence is available by adding another 1:1 high inductance transformer in the coax line at the radio.
I think more could be done to optimize this experimental system, but it does work surprisingly well, and is still useable up to HF, at least for 22m HiFER reception.
Cheers and 73
Ed