Dallas Lankford's URM-25D notes (11-1988 / 1-1994).
(1) Dallas Lankford was one of the editors of Hollow State Newsletter (1983-2000). The HSN was originated as the R-390 user's group that was part of the 80's/90's "boatanchor" boom, this group contributed to popularize the R-390A receiver.
(2) Dallas Lankford's URM-25D notes (11-1988 / 1-1994).