Try some creative Googling. FWIW, WR has a website

I always Google before posting in the newsgroups. Don't want to abuse
the generosity of the good folks here who are willing to share their
knowledge.

The WR website says the model 50A50-206 is obsolete, and they removed
any documentation that might have been there at one time. I was hoping
someone might have a copy squirreled away.

EJ