This morning whilst aligning the ISS AOM there was no diffracted beam irrespective of the AOM
orientation.  The 80 MHz signal in to and out from the AOM driver was measured.  The output
of the driver was too low [~18.4 dBm (3.4 dBm + 15 dB attenuation)] for any noticeable diffraction.
The RF amplifier gain simply was not there.

    As a side note, the RF spectrum was measured.  80MHzIn2.tif shows the input RF spectrum
from 10 MHz to 120 MHz and is relatively clean.  The output spectrum is in 80 MHzOut2.tif
where a number of extra peaks are present.

    The AOM driver, which should produce at least 33 dBm, was examined in the EE Lab.  For a
power supply voltage of +18 V, it could not produce more than ~30 dBm regardless of modulation
input.  Increasing the power supply voltage to the nominal +24 V, the AOM driver easily produced
33 dBm.  Keeping the modulation input voltage fixed, as it is whilst the ISS is unlocked, and
reducing the power supply voltage by 1 V reduced the AOM driver RF output power.  The
suspicion is that either the power supply voltage was reduced some how and the AOM driver
latched.  The same behaviour was observed in a different unit that was, until now, thought
to be faulty.

    A dedicated power supply line will be pulled some time next week just for the AOM driver.