Hi Raj I have the fan outside the case about a foot away and the receiver is picking up a sound like a buzz from the high RPM of fan.From reading what Arv said and internet research the dc brushless motors have this problem. Im going to try some RC Filtering and IC filtering and see if that works. Thanks Ron
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--- In BITX20@..., Raj <vu2zap@...> wrote:
What kind of noise Ron?
Hash noise means you will need HF filtering. A bifilar choke + small value caps (like 10nF).
Hum means you will need magnetic shielding IMHO. Most of these fans I have seen have 3 coils on a PCB that are not shielded. I am sure the pulsating mag field extends right out of the fan at the center. Increasing the distance from your rig should reduce the noise, if this is so then you need a magnetic (iron) shield (a round plate) at the center of the fan.
Raj, vu2zap
At 27-05-2013, you wrote:
Bought a nice brushless silent geld fan,but was surprised to hear all the huge amount of noise in receiver. Best way to clear noise, Cap? What size? Thanks all techs Ron
