If the current level the camera requires is low enough, probably - I'd
think about putting some spike protection etc. in there, I'm sure the
schematics (guys?  I cannot find 'em, tonight) would help.  You get
*huge* over- and under-voltages on a car +12V bus, especially when
starting the car or when the alternator goes from full charging to
'idle' (a "Load Dump"), or you turn the headlights off (and the
alternator does the same "Load Dump" switching);  the Radio Shack unit's
probably designed to handle those, somewhat, BUT, how pricey is your
camera?  (I could have sworn there was something off of
http://www.bobblick.com/ about a Tachometer or something?  Long day <G>)

To attenuate the sound controllably, look at an "L-Pad", that's a
composite potentiometer unit that gives you constant impedances.  If you
know the percentage you want to decrease volume by (and remember,
loudness isn't linear!), you can just use a few resistors & do the same
job an "L-Pad" does, all it is is 2 pots connected together properly, to
preserve impedance matching...

  Mark

john pearson wrote:
>
> I am using a 9Vdc composite video camera with mike in my car. I was
> wondering if a DC converter to 9v like the Radio Shack version is safe to
> operate the camera from the car battery.
>
> Also, I need to attenuate the audio. The motor volume overwhelms the mike
> and distorts the sound. The sound and video outputs are going into a VCR. Is
> there a way I can attenuate the sound before it gets to the VCR?
>
> Thanks
>
> John