User Manual

1. Set up a 48V power supply, current limited to a little more than 1.2 A.
2. Remove both fuses on the amplifier. Turn both bias potentiometers to their
maximum resistance (minimum gate voltage).
3. Apply the 48V supply to the B+ terminal. Verify that the bias (gate)
voltage is at or near minimum by measuring the voltage at the gates of
the device. This voltage should be less than 1V. Install one of the fuses
adjust one of the potentiometer for 500 mA drain current. Then adjust the
other potentiometer for a total current of 1A.
4. Connect a 20 dB 1W attenuator to the output of the amplifier as shown
below.
5. Apply B+ to both supply connections of the amplifier.
6. Apply a low level sweep to the module and measure the DC input current
(about 1.2 amps) and gain. Amplifier gain by itself should be 15 to 17
dB, and with preamp included, overall gain should be between 38 and 41 dB.
Sweep response should be flat within 1 dB over the band as shown in the
sweep diagram from page 4, repeated below. Note that these sweep curves
are applicable to the push-pull FET amplifier only and the preamp is not
included.