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Posted by Rick Merrill on 10/07/05 15:23
Smarty wrote:
> Most if not all of the camcorders do AGC on the audio inputs, and have at
> least 60 to 80 dB of dynamic range. Virtually all the camcorders use
> unbalanced inputs. I have build T-pad attenuators with a simple 3-resistor
> T-network to do precisely what the original post asked for, and the
> attenuators which do around 30 or so dB seem to work just fine. Putting in
> too much attenuation forces the AGC to "gain-up" and crushes the SNR by
> raising the noise floor.
>
> Smarty
>
>
> "Larry J." <usenet2@DE.LETE.THISljvideo.com> wrote in message
> news:Xns96E78BC2755B6thefrogprince@68.6.19.6...
>
>>Waiving the right to remain silent, "Smarty" <nobody@nobody.com>
>>said:
>>
>>
>>>You will not need equalization, but you do need to attenuate the
>>>line level signal (nominally about 1 millivolt into 47K ohms)
>>>down to a few microvolts (also at the same impedance). Thus an
>>>attenuator / pad of about 30 dB should do it.
>>
>>An even larger pad could be required. Unbalanced live levels are
>>generally -10 to -20db. Balanced can be as high as +8.
>>
>>--
>> Larry Jandro
>> Video Engineering & Equipment Rentals
>> Scottsdale, Arizona, USA
>> [Remove spamtrap in ALLCAPS to reply]
>
>
>
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