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Q. What's the source of my studio interference?

In the middle of November I sat down to do some recording, to find that interference was affecting my equipment. It hasn't gone away since, although I've tried different microphones, cables, and even a different mixer. The interference also affects my practice amp and my electronic keyboard. I checked previous recordings done in August and September but could not find a trace of it.

I tried turning off all the ring mains and lighting circuits in my home, apart from the one for the equipment, and have even tried my gear in my neighbour's house, but it is still there. I then took the equipment to my father's house to see if he could work out what was causing the interference, only to find that it had gone.

I've thus decided that it isn't a problem with my equipment, as it works perfectly well at my father's house, and that it isn't anything in my house (fridge or freezer, for example), as the interference is also present in my neighbour's house. It's at about 8‑10 kHz, is there for 24 hours a day, its level drops and increases with the position of microphone and cable, and it affects every room of the house.

On asking around to find out whether any new electrical equipment has been fitted in my neighbourhood, I discovered that a new aerial has recently been erected at the local police station, just a few hundred yards away. I was also told that TV reception in the local area has been affected. On investigating, I found that my TV is clear when connected through the digital cable, but when it's connected with the old set‑top aerial there's interference on all channels. I further found that there is interference on the radio.

The police tell me that a new aerial has been erected, which is the first of its kind, and that they are having teething problems with it. I logged a complaint and within a day was contacted by Police Headquarters and asked for further information. They then passed me on to British Telecom, who installed the aerial. BT contacted the Radio Communications Agency, who said that as the interference was not on a TV or radio it was not their concern.

Have you or any of your readers experienced this sort of thing before? Do I have rights in this situation, and are there any regulations which I can use?

Andrew J Green

Technical Editor Hugh Robjohns replies: It sounds very much as though the police aerial is the problem, and that they are aware they are causing a nuisance.

You mentioned that the interference is affecting both your TV (on a conventional aerial) and the radio, and therefore the problem is very much the concern of the Radio Authority. I would get back on to them and complain most strongly. It might also help if you talk with your neighbours in the vicinity of the aerial, to confirm that they are also having problems. The more names you can produce, the stronger your complaint will be.

Without measuring the field strength from the aerial, it is hard to know where the interference is breaking in, but I would suspect the unbalanced connections in your equipment. You could try pseudo‑balancing them (try searching the SOS web site for some tips), which might help.

The last resort would be to create a Faraday cage for your equipment — which means lining your studio with earthed tinfoil! However, that's an ugly, expensive and extreme solution, and it's difficult to ensure effective screening around doors and windows.

The best bet is to keep whinging to the police, BT and the Radio Authority. Get everything in writing, if you can. Talk to the local newspaper about fears of electromagnetic radiation. Lots of mobile phone aerial masts have either been taken down recently or prevented from being raised for this very reason. Planning departments are getting very nervous about it these days.