[evlatests] high level 3-bit sampler summary

[Mike Revnell]

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.
>
> _______________________________________________
> evlatests mailing list
> evlatests at listmgr.cv.nrao.edu
> http://listmgr.cv.nrao.edu/mailman/listinfo/evlatests
>
>