It's been a while since I've been down that way, but the last I remember, is that Newberg had their own 4 channel system that hits perfectly anywhere within the city limits of newberg, but one square inch out of the city and you lose it.
With the rest of yamhill county continuing the mpt1327 experiment, I'm not sure if that is still valid or not htough. I know there's history there.
THe database should have what was accurate a year 1/2 ago or so, the last time I was in that area and reconfirmed the stuff.
joe