Re: Electronics Readout Characteristics

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

Hi Gerard,

That's good. I also forgot to mention that Yves measured the gain 
yesterday by looking at the pulses at the input of the shaper (Hi-Z and 
math) on the header connector and getting the ratio to the output. So, 
it seems that there his shaper may have some other gain of 3.2. The best 
thing is to get his board here and check it/modify it.

Regards,
Fernando

Gerard Visser wrote:
> Hi again Fernando,
>     I just noticed that the document linked below also had an 
> (unstated) measurement of effective gain of the shaper by basically 
> the same method you followed. See the 2 figures on page 3, 10%-100% 
> pulse amplitude at input of shaper was 176 mV and at output was 382 
> mV. [The input was probed with a high impedance differential probe 
> (Tek P6247), with the shaper terminating the cable as usual.]
>     So the effective gain was 2.17, in excellent agreement with your 
> result.
>     I didn't write down which exact board I did this too, but it is 
> highly probable that this was done on the board which is now in Yves' 
> possession.
>
>     Gerard
>
>
> Gerard Visser wrote:
>> Hi Fernando,
>>         Sorry I didn't write back earlier... I attach here below your 
>> other
>> email and a combined reply, thanks!
>>
>> Hi Fernando,
>>         The CDC and the FDC anode shapers should be identical. You have
>> implemented exactly the changes listed on page 5 of
>> http://argus.phys.uregina.ca/gluex/DocDB/0007/000736/003/Receiver_Shaper_Setup_for_GPC01.pdf 
>>
> ...
>
>> Fernando J. Barbosa wrote:
>>  > Hi Gerard,
>>  >
>>  > I know you are busy with the fADC but I just want to check some info
>>  > with you.
>>  >
>>  > We have measured the gains for the shapers and are as follows: FDC
>>  > anode=2.16, FDC cathode=10.42 and CDC anode=3.2. The first two
> ...
begin:vcard
fn:Fernando J. Barbosa
n:Barbosa;Fernando J.
org:Jefferson Lab
adr:Suite #10, 12B3;;12000 Jefferson Ave.;Newport News;VA;23606;USA
tel;work:757-269-7433
version:2.1
end:vcard