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Hi Ben,

Not sure if this will be your problem, but our new SP8 is sensitive to
electronic interference - no wifi or mobile phone use in the SP8 room or
you get horizontal interference similar to what you describe.

cheers,
Rosemary

Dr Rosemary White
CSIRO Plant Industry
GPO Box 1600
Canberra, ACT 2601
Australia

T 61 2 6246 5475
F 61 2 6246 5334
E [log in to unmask]

On 14/12/12 10:07 AM, "Ben Melchior" <[log in to unmask]> wrote:

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>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
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>
>Hi Listers,
>
>I have a technical question regarding the tuning of PMT modules on a
>confocal 
>system.
>
>We have recently replaced a PMT module on our LSM5 system.  Although we
>now can get a signal and observe our cells we still having what looks
>like 
>electrical interferences (horizontal stripes) that impact the quality of
>our 
>images when scanning.
>The image acquisition now requires a much lower laser power (633nm line)
>than previous, but inversely, an extreme detector gain was needed (over
>1100!). If I try to increase the laser power and decrease the PMT voltage
>it 
>looks like the PMT saturates or there is no more signal.
>Other channels/lines have clean signal. Nothing wrong with the optics.
>
>Is there any electronic engineer or specialist with any thoughts
>regarding 
>adjustments, tweaking, or calibration of the PMT module? Or any pin on
>the 
>board that I should check to see if the control voltage to the PMT is
>right?
>
>Thank you,
>
>Ben