Feeds are back - signals will be a little weaker than normal. Preamp and/or preamp power supply issue. New preamp won't be installed for at least another week. Since there are eight receivers at this location there is considerable power splitter loss (which the preamp was designed to overcome).
Seem to still hear many or most aircraft on the ground, so it will suffice for now.
P.S. Thanks Marco for the remote hands!