Fan Noise On the on the carrier

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stylzmovement
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Fan Noise On the on the carrier

Post by stylzmovement »

i have a transmitter here , there are 3 dc 12 volts fans in the unit where ever the unit is on , ( no audio ) i will hear the fan noise on the carrier ( the fm Frequency is 106.1 fm ) .
what can get rid of the noise from getting into the audio on the frequency?
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pcs
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Post by pcs »

Easiest fix is to power fans from separate source.

Another fix is to power fans from mains, if mains is available inside the box.

Marko
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Marko - PCS Electronics
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stylzmovement
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Post by stylzmovement »

that mean the fans will be now has to be ac fans ..
are there any choke that i can use.
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pcs
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Post by pcs »

Yep, LC filters might help as well, and routing fan wires as far away as possible from other stuff.
Best regards,
Marko - PCS Electronics
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Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
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stylzmovement
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Post by stylzmovement »

ok, if i use a LC Filter , that will be for the RF, but the fan noise will still fall between the audio frequencies of 20Hz to 20Khz.
what i am looking for is something to stop or reduce the fan noise from the audio , i cannot use ac fans due to no available fans with the specified CFM.

so are there something like air core to reduce the noise?
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pcs
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Post by pcs »

LC filter will help, try it. Caps should be of the 1nF, 100nF, and 100uF values,
in parallel. RFC (coils) should be about 220uH or so, permitting sufficient
current without heating.

If you're using MAX PRO 3+ replace it with 3000+ model, you will notice the noise
is not there anymore at all.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
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