[Halld-tracking-hw] HVB - FINAL VERSION - and fADC

[Fernando J. Barbosa]

Hi Naomi,

The gain was halved from the original on the modified HVB to fit the 
amplitudes within the fADC range. From your histograms, it seems that 
you need to double the range of the fADC with the original HVB. Correct?

What caused the dramatic change? Gas? Leaks?

Certainly we need to discuss this as there will most likely be an impact 
on the FDC, if we are to have one fADC for both the CDC and the FDC.

Best regards,
Fernando




Naomi Jarvis wrote:
> Hi Fernando and Gerard,
>
> I have some results with cosmics and the new fADC online here: http://www.jlab.org/Hall-D/software/wiki/index.php/New_fADC_with_cosmics
>
> This is still a work in progress, we can see (top row of histograms) that the gain in the new fADC is about 1/2 of that of the Struck fADC (&shaper).
>
> Is it possible to change the full scale range of the new fADC?
>
> >From previous work with the Struck fADCs, we know that the preamp output saturates at approx 0.5V (measured after the shaper), so we would only be using half the range of the ADC if we use the unmodified HVB.
>
> We would like to put this on the agenda for the tracking meeting on Wednesday.
>
> Naomi and Curtis.
>
>
>
> On Apr 8, 2011, at 1:38 PM, Fernando J. Barbosa wrote:
>
>   
>> Hello,
>>
>> I have attached a few drawings of the final HVB. Changes from the first version are as follows:
>>
>> - signal attenuation network added to each signal (back of the PCB)
>> - location and footprint of brackets
>> - channel numbering order to agree with fADC125 (0 through 23) (top carries the preamp card - see HVB_FINAL_TOP_SILK.PDF).
>> - a few minor dimensional and cosmetic improvements.
>>
>> I have reviewed these changes with Slava but please take a look and let me know if you have any questions as I plan to start procurements next week.
>>
>> Thanks and best regards,
>> Fernando
>> <HVB_FINAL_TOP_SILK.pdf><HVB_FINAL.pdf><HVB_FINAL_BOT_SILK.pdf><barbosa.vcf>
>>     
>
>   
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