5. DC Log Amplifier Adjustments
There are three DC log adjustments; limiter phase, linear fidelity, and log fidelity.
Assembly
Adjusted
A4 log
amp/Cal
oscillator
Related
Performance
Tests
IF Gain Uncertainty
Scale Fidelity
Description
These three adjustment need only be done under the following conditions:
Limiter phase Only if a repair is made to blocks F, G, H, I, or J.
Linear fidelity Only if a repair is made to blocks C, D, F, G, H, I, J, K, 0, IF gain
accuracy, RBW switching, or log fidelity.
Log fidelity Only if a repair is made to blocks D, F, H, K, IF gain accuracy, RBW
switching, or log fidelity.
If multiple adjustments are required they should be done in the following order:
1. Limiter phase
2. Linear fidelity
3. Log fidelity
TEST CABLE
----------------------,
:
I
I
SPECTRUM
I
I
SK16
Figure 2-9. DC Log Adjustment Setup
2-30 Adjustment Procedures
