The following case study sourced from Grant VK5GR
One thing I have found very helpful for finding sources is to build this kit:
https://www.minikits.com.au/electronic-kits/high-frequency/hf-active-antenna/EME234-HF-Active-Loop
Click this link to visit minikits website.
For the antenna, get some ½” soft copper pipe and form a loop about 30cm diametre and use that in place of the wire described in the construction notes – now you have a portable DF antenna. The nulls are very deep. Ive found numerous (noise) sources this way. Add a stepped attenuator to help you walk all the way up to the source too.
The alternative way to combat it is to run a noise canceller. I have used two different types.
1) http://users.tpg.com.au/ldbutler/NoiseCancelling.htm – this is my favourite – extremely simple but very capable of taking out single noise sources when you have an aux antenna that can equally hear the noise but is a bit deaf to the wanted signals.
2) https://www.vk5tm.com/homebrew/noisecancel/noisecancel.php – I have used this version as well – seems better suited to broadband noise soures.
A combination of DFing it to the source and cancelling it before it gets to your rx front end are the ways I am managing to keep my station on air currently. It certainly reduces the enjoyment of the hobby everytime a neighbour brings home a new piece of electronic garbage.
Acknowledging Grant VK5GR – thanks Grant