Re: HVB feedback

["Fernando J. Barbosa" <barbosa@jlab.org>]

Hi Yves,



Yves Van Haarlem wrote:
> Hi Fernando,
>
> I just started to test the new prototype and noticed a few things:
>
> The mapping on the board is reversed after the shaper board: so 
> channel 1 ends up in channel 16, 2 becomes 15, ...
Nothing has changed on the mapping - the routing goes straight from the 
inputs on the HVB to the preamp and the rest is the same (cable, etc.) 
Perhaps you are referring to the labeling on my drawing for the 
connector to the straws. I will check.
>
> Channel 3-4 on the HVB do not work and have a baseline offset of 768 
> mV compared to the working channels that have an offset of 200 mV. 
> This offset occurs as soon as you connect the preamp to the board. It 
> does not matter if the HVB is connected to the prototype or not. I 
> measured the HV board but could not find anything suspicious. I also 
> tried the other HVB and it showed the same behavior. I am doing a 
> measurement with the fe-55 source now but tomorrow I can compare with 
> the old setup and see if I see the same there.
Is the preamp OK (channels 3, 4)? Please try with the interposer as a check.

Regards,
Fernando


>
> Best regards,
>     Yves
>
>
>
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