The third photo is intriguing; I don’t believe Aux Unit bases had either electricity or radios. It could indicate that this is a Zero Station. Do you have any more photos of the cable? I suspect its electrical cable but need to see the ends to confirm. The location of electrical wiring in a wooded area is not ‘normal’. What about the void under the corrugated iron in the same photo? What’s in there?
Thank you very much for your suggestion. I have only now realised that I have not updated this post in a while. I should have added that some of the items have in the meantime been identified or were found to have no connection with Aux. Apologies! The cable is one of these - it belonged to a number of other, unrelated items that were dumped here by a farmer.