The Local Repeater with the CTCSS receive decoder turned on.
A look at the receive preamp in the back (later removed).
146.620 McDonald Observatory
2005 11 21 Trip
Doug - N5HYD replaced the ailing G.E. MastrII VHF Local Repeater with a brand new Kenwood TKR-750 commercial grade repeater on this trip.
He also added Analog Delay Modules to the RLC-1 controller. These are added to eliminate the first few milliseconds of repeated audio from being chopped off while the CTCSS decoders get up to speed.