9
ISOMET
A typical relationship between RF drive and efficiency for a correctly aligned AOM740-H at
10.6um is illustrated below.
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0
10
20
30
40
50
60
70
80
90 100 110 120 130 140 150 160
RF Pow er (W)
E
ff
ic
ie
n
c
y
3.6
Locate the PWR ADJ access holes on the driver end plate.
The 40MHz RF Power adjuster is closest to the LED stack
3.7
With an insulated alignment tool or screwdriver rotate both PWR ADJ potentiometers fully
anti-clockwise (CCW) i.e. OFF, then clockwise (CW) approx 5 turns.
3.8
Apply DC to the amplifier.
3.9
Apply a constant TTL
high
signal to the Freq Modulation input on the D-type connector of the
RFA741. Connect pin 7 of ‘D’ to the TTL signal and pin 14 of ‘D’ to the signal return (0V).
3.10
Apply a constant PLC
high
level (typically 12V or 24V) to the digital gate input on the D-type
connector. Connect pin 8 of the ‘D’ to the Signal and pin 15 of the ‘D’ to the signal return.
3.11
Apply a constant PLC
low
level (less than 2V) to the POT SELECT input (S0) on the D-type.
Connect pin 1 of the ‘D’ to the Signal and pin 9 of the ‘D’ to the signal return.
A low level will enable power adjustment using the Manual pots.
