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Posted by Rick Merrill on 10/07/05 15:26
Andy & Kim wrote:
> "Smarty" <nobody@nobody.com> wrote in message
> news:iv-dnTLi_8s_CNjenZ2dnUVZ_sidnZ2d@adelphia.com...
>
>>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]
>>
>>
> Thanks for the advise guy's. Smarty could you give me some values of the
> resistors I would need for a T-pad attenuator, just as a guide.
>
> Andy
>
>
>
I second the request!
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