AnsweredAssumed Answered

ESA-L E4408B High band problem

Question asked by suribe on May 6, 2015
Latest reply on May 12, 2015 by MikeM
I have a E4408B apparently with a flatness failure in high bands

The instrument completes the power on routine and performs the auto align without any problem.
Low Band works fine.
High Bands (from 1 to 4) have an attenuation of 10dB aprox in all frequency above 3GHz

Using the service manual, I checked the state of A8, RF Attenuator and RF in connector. They are fine.
But, I suspect of LOIS (A8A4), RYTHM (A8A6) and A7A4 (FEA).

The amplitude of the LO of LOIS output (A8A4J2), is 3dB down according with the service manual specification
The IF output for High Bands, from RYTHM (A8A6), is 10dB down according with the service manual specification

I checked the RYTHM in other E4408B and works fine

Could be A7A4 (FEA) the problem?  

Outcomes