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Greg Bullough wrote: > At 06:14 PM 2/4/02 -0800, [EMAIL PROTECTED] wrote: > >----[Please read http://ercoupers.com/disclaimer.htm before following > >any > >advice in this forum.]---- > > > >Just read the article. It speaks of ALTERNATOR noise, not generator. > >Maybe a generator can't produce this kind of disturbance. > > Both alternators and generators can make nasty noise. As can the > ignition circuit. > > To confirm which it is, go flying. > > Turn on the radio. > > Hear the noise. > > Turn off the generator switch. Is the noise gone? > > If not, then kill the mags, one at a time. Does the noise change? > > If you're brave, and high enough, kill both mags. Does the noise (no > not the engine noise) change? > > Now you've isolated the noise to either ignition or charging system. > > As someone suggested, grounding is critical for noise suppression on > charging systems. Bad generator brushes can also be noisier than they > should be. > > Grounding is also critical for ignition system shielding. A shield > doesn't work unless it's grounded, and at magneto voltages this means > a GOOD ground, not a half-assed 30-year old semiconducting > grease-covered piece of braid. > > You also have to verify the ground on the antenna side of the radio. > As well as the antenna connection. As well as the quality of the coax > going to the antenna. Leakage anywhere here, or a crappy job of > putting on the connectors, or corrosion where the antenna ground > contacts the airplane at the antenna end can all lead to more receiver > noise than is warranted. > > Your proposed fix was to put an alternator in. Very likely that would > just change the noise not at all or change it from generator buzz to > alternator whine. That would be quite a $1000.00 experiment. > > Shoot the bug. Find the offending system or systems, and check their > grounding and shielding. > > Greg > > > It's not complicated! Both alternators and generators produce DIRECT > Current. The noise is from brushes in the gen. and probably the diodes > in the alt. This noise gets into the 12 volt line to the radio. Wag Aero > sells a filter for $80. This should cure alt"whine' or gen 'buzz' if you > have followed Greg's suggestions. Craig 9772M ==^================================================================ This email was sent to: [EMAIL PROTECTED] EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Sid.bAhN69 Or send an email to: [EMAIL PROTECTED] T O P I C A -- Register now to manage your mail! http://www.topica.com/partner/tag02/register ==^================================================================
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