[Halld-tracking-hw] new preamp

[Fernando J. Barbosa]

Hi Naomi,

My apologies but I sent you the preamp configured for discriminator use. 
Please send it back and I will send you another one tomorrow.

The polarity of the cable has changed in line with the rest of the 
electronics readout. Nothing else has changed. The current is OK. Please 
keep the cable until you get everything going.

Best regards,
Fernando



Naomi Jarvis wrote:
> Hi Fernando,
>
> (I just joined the group at CMU with Yves and Curtis.)
>
> The new preamp and cable arrived safely, thankyou, but when we 
> installed them there was a huge amount of noise and no real signal.  
> We put 3.2V on the new preamp, and it drew approx 420mA, this is in 
> line with 275mA which the old preamp takes.  Also we tried using the 
> new cable with the old preamp and it seems that the polarity is reversed.
> We have uploaded the scope traces to 
> http://www.jlab.org/Hall-D/software/wiki/index.php/Preamp_2
>
> Do we need a new HV board?  Have the pin settings changed?  We would 
> like to keep the old cable here until we get the new setup working.
>
> Best regards,
>
> Naomi.
>
>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: barbosa.vcf
Type: text/x-vcard
Size: 188 bytes
Desc: not available
Url : https://mailman.jlab.org/pipermail/halld-tracking-hw/attachments/20100406/a0a86e29/attachment.vcf