On 23 June 2009, NOAA will implement the following VTX configuration
changes:
NOAA-19‘s operational VTX frequency will be switched to 137.1 MHz (from
VTX2 to VTX1). The change will occur during rev 1936 between the first
command time of 1824Z and the last command time of 1838Z.
NOAA-18‘s operational VTX frequency will be switched to 137.9125 MHz (from VTX1 to VTX2). The change will occur during rev 21088 between the
first command time of 1852Z and the last command time of 1904Z.
This change will not impact APT data on any other NOAA satellite since
both of the NOAA-18 and NOAA-19 VTX frequencies are different than the
rest of the constellation.