[evlatests] BD T304 power meters and attenuators

[Michael Rupen]

> On Thu, 10 Jun 2010, Michael Rupen wrote:
>
>>  On Thu, 10 Jun 2010, Barry Clark wrote:
>> 
>> >  I'd incline to make LoIfSetup default to SETANDREMEMBER for 8 bits
>> >  and SETLEVEL for three bits for all basebands, and OPT could just
>> >  not set things unless there's some special reason to change.
>>
>>  What do these two options do?
>
> SETLEVEL is what I called "ALC".  It servos the attenuators
> at the beginnin of a scan to acheive a desired power level.


Which means we also have to get serious about how long it takes to set
the attenuators, if we want to use 3-bit samplers as well as fast switching
at high frequencies.

              Michael