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| Thread ID: 79734 | 2007-05-30 08:39:00 | Car audio and noise suppression - Help !! | Myth (110) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 554410 | 2007-05-30 08:39:00 | Any electronics whizzes out there? Since my last car was written off as a result of being rear-ended, I have acquired my parents old car (they were selling it anyway, I just bought it off them). I notice there is a radio-static type noise when playing on the radio (haven't noticed it in the CD player) ONLY when the engine is on. When the engiine is off, the radio is clear of all noise (other than whats playing on the radio). The noise does get slightly louder as the revs climb, and falls as the revs drop. As the antenna was dodgy, I replaced that. No change Have also connected an inline noise suppressor to the MAIN power lead of the radio/cd player (latish model Pioneer). Still no change Running out of ideas, need help :help: |
Myth (110) | ||
| 554411 | 2007-05-30 08:52:00 | comman problems..... poor earth. make sure there is a decent earth from the radio to ground. also make sure their is a decent earth from the head of the motor to car chassi. you didn't say what car (petrol/deisel, age, motor type). |
tweak'e (69) | ||
| 554412 | 2007-05-30 08:55:00 | comman problems..... poor earth. make sure there is a decent earth from the radio to ground. also make sure their is a decent earth from the head of the motor to car chassi. you didn't say what car (petrol/deisel, age, motor type).91 Corona petrol. The leads and distributor cap have also been recently replaced as well, but I notice there is no coil |
Myth (110) | ||
| 554413 | 2007-05-30 09:00:00 | In the good old days it was necessary to put a suppressor onto the alternator/generator to cut the noise. The increase you hear in the noise is the speeding up of the alternator. Have a chat to a friendly auto electrician. | Bryan (147) | ||
| 554414 | 2007-05-30 10:42:00 | The alternator is a "whine" that changes in pitch with revs. The ignition noise is more like static, that is slightly worse under accelleration. You comment that new leads were fitted, that could be the problem. If they used normal ignition (spark plug) cable with copper conductor and the original was suppressor cable (with a fabric impregnated conductor) then you will get the noise unless you use the correct spark plug cables. |
godfather (25) | ||
| 554415 | 2007-05-30 10:50:00 | the coil is probably built into the distributor. a little unusual to get alternator noise unless there is a fault on a latish model car. might pay to get a sparky to check that. however earth faults can sound similar so its pays to check that first. i know of a few vehicles that suffer faults from the engine earth strap connections going rusty. btw...your not listening to an AM station are you ? godfather....i don't think they have made copper HT leads for the last 50 years or so ;) :D might you you can still get racing leads which are not suppressed. or they simply could have poor connections onto the spark plugs and cap. |
tweak'e (69) | ||
| 554416 | 2007-05-30 10:51:00 | I would be surprised if anyone would have gone to the effort of putting copper leads on that model car. Copper leads are not made to suit particular models so these would have had to be made per lead and this takes a lot more time than grabbing a set of supressed leads off the shelf A simple test if it is the alternator would be to quickly test it with the alternator belt removed (ONLY if you know what you are doing should this be done). But I would be more inclined to double check the simple things first - as per Tweak'e, check earth leads to radio unit and engine to chassis. |
sam m (517) | ||
| 554417 | 2007-05-30 10:54:00 | the coil is probably built into the distributor. Yeah they are which is why the dizzy cap is fugly with a big square part. Although coils were inbuilt they were a lot more reliable than the traditional oil filled ones. |
sam m (517) | ||
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