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Thread ID: 28794	2003-01-01 01:31:00	OT - Get rid of Radio in my stereo?	Chilling_Silence (9)	Press F1

Post ID	Timestamp	Content	User
110230	2003-01-01 01:31:00	When playing a DVD from my PC through the stereo (Yes, I got a 3.5mm > RCA lead for it!! I hope thats right... ) the radio is extremely noticable when the surround sound speakers are in. Come to think of it, its always pretty bad when the satelites are plugged in. The front 2 main speakers and the front satellite dont get any radio at all when the back 2 satelites are not plugged in. When the back satelites are plugged in though, they all get pretty bad radio. Come to think of it, it happens when playing anything. The leads to the front speakers go under the house and then back up to them (The stereo is position at the back of the lounge) but the rear 2x satelites just have the cable running along the wall line on the ground. How would I elliminate the radio from coing through? Thanks guys Chilling_Silence	Chilling_Silence (9)
110231	2003-01-01 01:55:00	This is a not uncommon event :) It can be due to non-linearity in the stereo pre-amps causing rectification ie de-modulation of any strong radio program, like the National Program. Or maybe even dissimilar metals in the audio leads, or a bit of oxidation, also causing a rectifying action. Make sure all connections are clean, not dirty; check that your earthing system is ok and aim to have just one central common earthing point if possible for the audio (maybe you wont be able to do that); you could also try getting hold of some ferrite toroids, or the ferrite tubes you see on monitor vga leads and wind your audio leads through them, as many turns as you can get. It can be difficult to get rid of though.	Terry Porritt (14)
110232	2003-01-01 02:42:00	Yes, it always is 1251 AM Radio Rhema. So I should have an earth coming out of my stereo going into the ground somewhere? Thanks heaps :) Chilling_Silence	Chilling_Silence (9)
110233	2003-01-01 03:09:00	If you are near to a Radio Rheema transmitter then you will inevitably have problems. Long unshielded speaker leads can act as AM antennae, and if the lead from the PC to the stereo is long that could pick up too. The stereo earth and the PC earth ideally should be one and the same, at least should be on the same power point, so as to minimise earth loops. Winding the speaker leads and the input audio lead through ferrites close to the stereo will certainly help to suppress RF pick up. Lets see what Goddie and Billy T say on this.	Terry Porritt (14)
110234	2003-01-01 03:26:00	I agree Terry. I would pick that installing the ferrites as close as possible to the stereo would work, its difficult to do anything with earthing as many stereos dont have earths these days. Getting the right toroid may be interesting, DSE have Catalogue R5400, only 80 cents each, but they are 30 - 400 MHz. May work, and at the price an easy fix. Also they have Catalogue R5410 which is designed for EMI suppression at $2.55 each. While the 80 cent ones are designed for higher frequencies, 5 of the are only $4.00, so worth a try first. If you use large diameter speaker cables they will be too small however. (5mm ID, 9mm OD) The others would be slightly better at 8mm ID, 15mm OD but unless you can get a few turns around them look for larger ferrites. You may need to find where the Radio Amatuers buy bits in your area.	godfather (25)
110235	2003-01-01 03:28:00	> If you are near to a Radio Rheema transmitter then > you will inevitably have problems. Long unshielded > speaker leads can act as AM antennae, and if the lead > from the PC to the stereo is long that could pick up > too. Well, Perhaps we are. I know some other people in this area of AK who also get it through their stereo. I know the guy who works there actually, Rob Holding, and so I'll have to ask him, but for the time being I guess I could look into getting some sheilding for the cables. > The stereo earth and the PC earth ideally should be > one and the same, at least should be on the same > power point, so as to minimise earth loops. > Winding the speaker leads and the input audio lead > through ferrites close to the stereo will certainly > help to suppress RF pick up. Okay, I'll look for an earth, what should it be attached to? The PC Earth? BTW, it not only happens when playing the PC.. Currently my PC is shutdown, and when playing CD's its just as bad. > > Lets see what Goddie and Billy T say on this. Okay, cool, thanks!	Chilling_Silence (9)
110236	2003-01-01 03:30:00	..Okay, thanks godfather, I'll be off to Dick Smith tomorrow. As for noise in tonights DVD, I guess I'll just have to live with it! Thanks again :)	Chilling_Silence (9)
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