[Laser] first time, simple system, but problem

[Kerry Banke]

The LM386 will oscillate at MHz frequencies if not dealt with 
properly.  The power needs to have bypass caps right at the pins. 
Also the output needs to have a .05 uf  (0.1 ia ok) in series with a 
10 ohm to ground to prevent oscillation. We have several of those 
amps in use for our optical receivers here in San Diego and those are 
the standard problems we have found.
  - Kerry N6IZW -

At 04:57 PM 8/29/2006, you wrote:
>hey all, KB1LQD here, built the simple RX'er out of a 741 op amp, and a 386
>amp with a photodiode. It works, but there is a terrible occilation when the
>10k pot is at a volume point of anything decent, also, it seems like a
>signal is there or not there at all, (No background noise), any tips? the
>only long leads are the leads to the photo diode in the PVC pipe with a
>lens. Also, any tips on making an aiming system for the RX and TX, Also, how
>do I make sure the lens is perfectly in posistion with the photo diode?
>
>--
>73's
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