Specifications

Chapter 1 1-5
Overview
Characteristics
Maximum Input Level
The maximum allowable input level without damage is +20 dBm when the preamp is on.
The input level calculation varies for different PSA models. See below.
E4440A, E4443A and E4445A:
As mentioned, the maximum allowable input level without damage is +20 dBm when the
preamp is on. This is not the power at the input connector minus the on-screen input
attenuator setting. The maximum allowable input level is the power at the input connector
minus the actual input attenuation. This is because the preamp is located after the 0-4 dB
attenuator stages but before the 6, 10, 20, 30 dB attenuator stages. Therefore, the
attenuation value entered on the instrument is in most cases, not the input attenuation to
the preamp. Refer to Table 1-3 for the actual input attenuation.
E4446A and E4448A:
Here too, the maximum allowable input level without damage is +20 dBm when the
preamp is on. For the E4446A and E4448A, the on-screen attenuation is the actual input
attenuation to the preamp, therefore the maximum allowable input level without damage
is the power at the input connector minus the on-screen attenuation. Refer to Table 1-3 for
the actual input attenuation.
Table 1-3 Input Attenuator vs. Actual Input Attenuation
Input Attenuator
Setting > 3 GHz
Actual Input Attenuation
at Preamp Input for
E4440A, 43A, and 45A
Actual Input Attenuation
at Preamp Input for
E4446A, and E4448A
0 dB 0 dB 0 dB
2 dB 2 dB 2 dB
4 dB 4 dB 4 dB
6 dB 0 dB 6 dB
8 dB 2 dB 8 dB
10 dB 0 dB 10 dB
12 dB 2 dB 12 dB