jizzer Posted June 18, 2006 Share Posted June 18, 2006 Hello, Ihave just added this Microphone to my cctv system at home Ican now hear faint radio in the backgroung which becomes clearer if you touch the 2 short wires comming off the pcb board to the microphone which I assume is because I am acting as an aerial All the cams including this mic are fed from the same power supply which is This power supply The audio feeds into a modulator via a good quality screened 2 core and then is distributed around the house but I have disconnected the mic and fed it straight into an audio input on a TV and the same problem occurs.. Should the 0v on the power supply be taken to ground? would this Help? Any other suggestions? Thanks Link to comment Share on other sites More sharing options...
breff Posted June 18, 2006 Share Posted June 18, 2006 Do you live near a TV mast? My cousin had the same problem with his DJ console some years back when he lived near Crystal Palace. The solution was to totally shield the inside of the equipment and earth. Maybe try insulating it and wrapping in grounded tin foil..........worth a try, see what happens. The opinions I express are mine and are usually correct! (Except when I'm wrong)(which I'm not) Link to comment Share on other sites More sharing options...
jizzer Posted June 18, 2006 Author Share Posted June 18, 2006 Do you live near a TV mast?My cousin had the same problem with his DJ console some years back when he lived near Crystal Palace. The solution was to totally shield the inside of the equipment and earth. Maybe try insulating it and wrapping in grounded tin foil..........worth a try, see what happens. Dont live in close proximity to a tv mast the biggest near us is Emley moor . We once were picking up radio on the telephone line at our other house but the engineer attenuated it at the local junction box Might give it a go with the foil but anymore suggestions welcome Link to comment Share on other sites More sharing options...
jizzer Posted June 18, 2006 Author Share Posted June 18, 2006 or a radio ham in the area,i lived next to a radio ham,and had one of those wireless tv transmitters,always interference,turns out he was using a dodgy freq,not sure what that means but he was stopped and no probs now..try ofcom for info,they monitor radio freqs from all sorts of users and equip in the area.. The radio I am picking up is Radio 5 Live on the Am band Link to comment Share on other sites More sharing options...
antinode Posted June 18, 2006 Share Posted June 18, 2006 You have earthed the drain wire in the screened cable have'nt you, and at one end only? I agree it sounds like poor shielding or a loose earth connection somewhere in the installation. You could try moving the cables around aswell, you will usually find that the cable will only pick up interferance in certain locations unless it's a very strong signal. Trade Member Link to comment Share on other sites More sharing options...
jizzer Posted June 18, 2006 Author Share Posted June 18, 2006 You have earthed the drain wire in the screened cable have'nt you, and at one end only? I agree it sounds like poor shielding or a loose earth connection somewhere in the installation. You could try moving the cables around aswell, you will usually find that the cable will only pick up interferance in certain locations unless it's a very strong signal. Will give that a try Is it common practise to take the 0v dc down to earth on the psu? Link to comment Share on other sites More sharing options...
antinode Posted June 18, 2006 Share Posted June 18, 2006 Will give that a try Is it common practise to take the 0v dc down to earth on the psu? Not really. There are no advantages of taking 0v to earth because 0v is already connected to earth unless your PSU is double insulated. The drain wire (stranded, uninsulated wire inside the cable) MUST be earthed, or else the whole cable acts as a huge antennae and will pick up all kinds of interferance... Trade Member Link to comment Share on other sites More sharing options...
ian.cant Posted June 18, 2006 Share Posted June 18, 2006 The radio I am picking up is Radio 5 Live on the Am band If you hear any good rumours about Newcastle could you post them here? Link to comment Share on other sites More sharing options...
jizzer Posted June 18, 2006 Author Share Posted June 18, 2006 If you hear any good rumours about Newcastle could you post them here? [/quote The receptions not that good Sorted the problem! Earthed the screen cable and the radio has now gone to all especially Antinode Link to comment Share on other sites More sharing options...
morph Posted June 18, 2006 Share Posted June 18, 2006 or a radio ham in the area,i lived next to a radio ham,and had one of those wireless tv transmitters,always interference,turns out he was using a dodgy freq,not sure what that means but he was stopped and no probs now..try ofcom for info,they monitor radio freqs from all sorts of users and equip in the area.. Point to note here: There are many licensed radio amateurs that are licensed to use transmitting and receiving equipment, with in prescribed frequencies and power levels. Many items of home electrical equipment are made with inferior components and limited protection against things this. Generally cheap equipment by its very nature may be prone to receiving these signals. Remember if the amateur is using his equipment with the prescribed frequency and power level, then if your equipment is receiving his transmissions YOU are at fault, as you do not have a licence to receive these transmissions. Your first port of call when looking into radio interference would be to have a friendly chat with the amateur concerned, not OFCOM. If that doesn't resolve the issue then you can talk to Ofcom, look at there website and see what they will and can do if you are receiving unwanted transmissions along with the associated cost. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.