Don:
>Wondering who offers a small kit or PC board that offers a simple
>precision reference voltage source that one can use to check the
>calibration of a DVM?
Check out: http://www.qsl.net/w3fpr/vref.htm
Don's got a LOT(!) of other great info there, too.
http://www.qsl.net/w3fpr/
73,
Tom N0SS