LM386 RF suppression

[DrFrankenstein]

I built the LM386 utility amplifier based off the circuit provided in the manufacturers PDF file and am experiencing radio interferance. I don't know if it's short wave or what cuz there are these german people...some times French or British...or worst of all religious sermons!

Anyway, how does one filter out this gook?

 

[tlmadsen]

LR-circuit on the output and 220pF across the two inputs (+/-) of the LM3886.

Thomas

 

[mctylr]

Use the datasheets

See page 6 of National's LM386 datasheet.

For the lazy:
http://www.national.com/ds/LM/LM386.pdf

 

[DrFrankenstein]

Hey thanks for the replies and help, I knew it was going to be a simple capacitor filtering solution but none of the values I tried worked. Do I really need to go so far as to adding the LR circuit though?

 

[tlmadsen]

The need of the LR-circuit is very dependent on the load (including cable) that the amplifier sees, so start without and see how it works. A small powerresistor will actually have the same effect (say 0R2/5 w)

Have fun

Thomas