Greetings, My last post consisted of a mobility power supply from my old neighbour now passed, we resolved this problem by fixing his original power supply, I did contact the manufacturer of one of the devices and they was very helpful, I gave them all details and they even got the unit back, I got another one and that was the same, so in the end gave up with them and we fixed the original unit and that sorted that out.. However, and this has been going on some time, I just have had too much to do to deal with it, and now has come the time to do so.. We have this noise that comes up mostly in the afternoons, but when it comes it don’t stop until the following day, it completely wipes out all my HF work, from 6m down to 80m, I have several resonant aerials, mostly static loops as they are quieter than dipoles, we found this out when we moved here 4 years ago, the noise floor on all bands back then was 1-3db, now it’s common to get 9bd+ apart from the 10m vertical which is extremely low noise, however it still gets that buzzing which wipes out any signals I do get, on a good day the Vertical is zero noise floor, but it never last and come afternoon time in come the buzz's and signal 9's. Aerial’s all 60ft from any property 6m Static Delta Loop fed with quarter wave 75ohm feeder to aerial switch 60ft from shack. 10m 26ft long vertical dipole, again fed into switch 15m Static Delta Loop fed with 75ohm quarter wave to switch 20m Static Delta Loop fed with 50ohm coax to switch 80 Doublet fed with 450ohm ladder feed directly into shack Coax runs along a fence into property. All equipment is earthed to a separate earth rod using 10mm earth cable. No RF is escaping into the shack or leaking elsewhere. We have turned off all our mains power and run off battery, and then done the switch on test of everything we use here, and it’s not coming from us. We have got devices that do cause RF, but we used plenty of ferrite rings to eliminate those device rf noise issues, so we know its definitely not coming from this property. I have enclosed a short video of what it sounds like on AM, the noise floor is elevated to signal 9 plus, fluctuating from 7-9, but it’s that buzzing, I would like to narrow down what it could be, switch mode or lighting or what? I just don’t know and not experienced enough to tell. I can attenuate the noise floor down, and use a vast array of filtering, but I still got that buzz which wipes out any chance of hearing contacts, my Neighbours are ok, but I don’t think they would like me walking around in their homes testing, most are elderly and the others would think I'm nuts and wouldn’t let me in anyway, But that don’t stop me from trying to find out which possible property its coming from, also, if anyone recognises this type of sound, then it could narrow it down for me to ask my neighbours if they have anything like it and could I possibly test it, If I can’t get anywhere with that, then it will have to be a call to Ofcom to get them out and see what it is.. All I know is that this last 6 months have been a nightmare and my logbook has suffered for it, we have both spent a lot of time and energy in this hobby and now we can’t even use it, unless we go portable, which is not good due to my partner being disabled which was the whole reason we went into this hobby to start with as she can’t get about much, so the radio for her is a godsend.. Any info would be greatly appreciated.. So, thanks in advance to anyone contributing to this thread. Regards Kev..