Radio Whine - how to eliminate

[Whaanga]

I have a stock Sapphire radio in my bus which works well enough. But I often hear engine whine through the radio speaker. Is there a way to eliminate this noise?

Thanks,

Jeff
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Late 1973 Bay w/a transplanted 914 Engine

[airschooled]

Does it vary with RPM? Some alternators have condensers/capacitors on their main terminal to cut noise down. I also have one on my coil + post, not sure if it does anything…

Robbie
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[SGKent]

two causes.

if a whine then it is the alternator

If it is staccato it is the spark plugs

Most likely if a whine the condenser for the alternator is missing or gone bad.
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[Wildthings]

[Shonandb]

Google "A quick and easy way to stop that terrible whining noise coming through your car stereo speakers is to use a ground loop isolator or inline noise suppressor."
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76 Westy with a 2.5L Subaru SOHC + Vanagon (010) Automatic Transaxle
Build & Trip Thread: https://www.thesamba.com/vw/forum/viewtopic.php?t=758760
Previous 1973 Panel Bus:
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[KTPhil]

I have been able to improve such noise interference by making sure the radio has a good ground. When using a 6-12V inverter, make sure they are grounded together, not separately. If it still whines, check out the ignition LC filters.

[mikedjames]

The other reason why it whines could be that 40+ year old electrolytic capacitors inside the radio have dried out and need replacement, making it over sensitive to alternator noise. There may be nothing wrong with the wiring, but you do need to make sure that its ground connection is clean as well. You may gain an improvement fitting a big capacitor to the 12 volt power connection going to chassis to smooth out the supply ripple.. think high power In Car Entertainment parts..
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1974 VW T2 : Devon Eurovette camper with 1641 DP T1 engine, Progressive carb, full flow oil cooler, EDIS crank timed ignition.
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