Model A5-32 Operation And Service Manual
A5-32 Manual 29 April 2002
Page 8 of 10
Maximum Output
Connect the 10 MHz signal source to the input of the A5-12, and the spectrum analyser to any
output. Increase the input level until the third harmonic rises abruptly, showing that clipping is
occurring. Alternatively an oscilloscope may be used to adjust to maximum output. Transfer the
output to the RF power meter and read the maximum output level. Repeat at 10 MHz if required.
Spurious Outputs and Wideband Noise.
With the gain of the A5-12 adjusted for 13 dBm output with 10 dBm input at 10 MHz, disconnect
the signal source and terminate the input with the 5
0Ω
load. Connect the spectrum analyser to any
input and search for discrete spurii. Calculate their level in dBc related to the 13 dBm nominal
output. Measure the wideband noise, using a preamplifier if necessary to improve the spectrum
analysers’ noise figure, correct for measurement bandwidth, log amplifier, and detector.
Alternatively use a noise figure meter.
Input and Output SWR
Measure using a reflection bridge or network analyser
Setting Up
The only user adjustment required is to set the output levels. To do this proceed as follows:
1)
Remove the lid.
2)
Connect desired input between 0 and 13 dBm.
3)
Connect a spectrum analyser, oscilloscope with 50
Ω
input impedance, or RF power meter to
any output.
4)
Adjust output level to 13dBm (1V RMS) using the pre-set (VR1) on the main board.
5)
Replace the lid.
Note:
All the amplifiers are class A linear amplifiers. The gain may be set to provide any output level up
to clipping if desired.
