Edit: "Children of the Dog Star" (NZ 1984) aired in Britain in August '85. It features children in a rural setting, it's scifi and something in a swamp with a hole in the middle is recovered. Below is the recovery from the swamp and assorted mystery devices: ![enter image description here][1] ![enter image description here][2] Source: http://www.frequency.com/video/children-of-dog-star-1984/101862698/-/5-6263323 ------- It could have been a re-run of "Here Come the Double Deckers" from 1970-71. It takes place in a junk yard in London where a group of children live in an abandoned double-decker bus. It features a fair bit of tinkering and a robot in at least one episode. It was a joint UK-US production, which might explain the accents you remember. It was a deliberate attempt at creating something along the lines of "Our Gang"/"The Little Rascals". ![enter image description here][3] ![enter image description here][4] ![enter image description here][5] ![enter image description here][6] What the writers tried to emulate: ![enter image description here][7] [1]: https://i.sstatic.net/RHOvJ.jpg [2]: https://i.sstatic.net/SVUXX.png [3]: https://i.sstatic.net/xAzpr.png [4]: https://i.sstatic.net/gwpue.jpg [5]: https://i.sstatic.net/ThHjW.jpg [6]: https://i.sstatic.net/RBHIp.jpg [7]: https://i.sstatic.net/IHL7l.jpg