DEC AXV11-C analog board

[Douglas Taylor]

On 2/8/2022 5:22 PM, Jon Elson via cctalk wrote:
> On 2/8/22 13:34, Douglas Taylor via cctalk wrote:
>> Update on this:  I did put together a battery and voltage divider to 
>> test the AXV11.  The label on the A/D module says it brings the 
>> output from the multiplexer to one of the external pins.  I was able 
>> to verify that the voltage applied to a couple of the A/D inputs 
>> makes it through the multiplexer when selected using the CSR.  The 
>> next output available is from the Sample and Hold, and this is always 
>> pegged at +12v.  Am I wrong to assume that the sample and hold will 
>> 'freeze' its output when the A/D go bit is set?
>
> Well, it will probably only hold the approximate voltage for a few 
> seconds, but should be long enough to see on a voltmeter.
>
> Jon
>
I was only using a voltmeter to look at it.

I'm going to try 2 different measurements; (1) use a scope to look at 
the S&H signal on the AXV11 and see what it does over time, (2) look at 
the same S&H signal on the Data Translation board which seems to be 
working.