[evlatests] high level 3-bit sampler summary

[Doug Gerrard]

This DTS module was swapped out yesterday.

Doug


Mike Revnell wrote:
> I had a look at ea19/C2. It has an awful DC offset. I can only ascribe 
> it to the ADC chip. It will have to be brought back for repair at some 
> point.
> 
> Mike.
> 
> Ken Sowinski wrote:
>> Using testing of the new configuration mapper as an excuse I ran
>> several 3-bit sampler tests this afternoon and tried to have a careful
>> look at what each sampler was doing.  Here is the short summary.
>>
>> Hittite samplers.
>> In general these seem to require less drive, or have more internal
>> gain, than the teledyne-based modules.  Even with the output
>> attenuators set to 31 dB these samplers are being overdriven by
>> a lot.  The modules in ea03 and ea16 are worst; the one in ea25 is
>> almost acceptable.  To test how these samplers work when driven
>> correctly we can put together a test script which sets the T304
>> input attenuators to provide a few dB less power.
>>
>> Teledyne samplers
>> There is only one which is easily seen to be grossly wrong,  The
>> sampler for ea19/C2 (in module D303) claims to have a DC offset
>> of 3.5 bins and doesn't work well at all.  The remainder have no
>> problems that can be seen at this cursory level of inspection.
>>
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>>   
> 
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