Archive for Equipment Teardown

Teardown, Repair and Analysis of an HP 8562B 22GHz Spectrum Analyzer

HP8562B

In this episode Shahriar repairs an HP 8562B 22GHz spectrum analyzer. This spectrum analyzer has two input bands. The lower band which operates from 1kHz – 2.9GHz shows does not operate correctly and does not display any signal. The internal construction as well as the operation of the unit is explained along with a close look at LO distribution, input attenuator, dual-mixer and various filters.
During the debugging procedure it is also discovered that the Second Mixer is also damaged in this unit. A replacement unit was purchased however a replacement unit for the main first converter is too expensive to replace. As an alternative, a Mini-Circuit mixer is used as a replacement. The LO signal is routed to the external mixer via a microwave switch. In this configuration the LO is automatically switched to the correct mixer for each frequency band of operation. The unit is then verified for correct operation.

Teardown, Analysis and Part-Salvage from an HP 70001A Series Optical Microwave Analyzer

70000A

In this episode Shahriar performs a teardown and analysis of several HP 70000A modules. The modules include a 20GHz optoelectronic converter, 2.9GHz tracking generator, 10MHz/100MHz precision reference and a 22GHz spectrum analyzer.

Along with the teardown of these modules several microwave components are recovered for future use including amplifiers, VGAs, mixers, photo detector and OCXOs. The 22GHz spectrum analyzer module is preserved since it is simply too beautiful to destroy.

Review and Teardown of the Analog Arts SL987 USB Oscilloscope AWG Pattern Generator and Logic Analyzer

SL987

In this episode Shahriar takes a close look at the Analog Arts USB based mixed-domain instrument. The SL987 offers an oscilloscope, arbitrary waveform generator, FFT-based spectrum analyzer, pattern generator and logic analyzer in a compact form factor.

The teardown of the unit is presented along with the datasheet of every major component on the PCB. Some design limitations and concerns are presented along with basic performance verifications.

Review, Teardown and Experiments with a Keysight MSO-S Series 10-bit 20GS/s Oscilloscope

MSO-S

In this episode Shahriar does an extensive review and teardown of the Keysight (Agilent) MSO-S Series 10-bit 20GS/s Oscilloscope. This scope supports bandwidths up to 8GHz and 400M points of memory per channel. With hardware 10-bit ADCs as well as an ultra low-noise front-end, this scope offers an impressive dynamic range on all four channels. All scope features are software upgradable.

The teardown consists of a close look at the acquisition board and the system blocks diagram. Various elements such as the ADC structure, FPGAs, memory and the time-base are all examines. The scope offers a +/-12ppb time-base with a 100fs jitter noise floor. Some basic performance measurements are also presented such as noise and SFDR.

The wireless experiment shows the performance of the scope in demodulating very low-power signals on an RF carrier. A -75dBm 2.5GHs QPSK signal can be demodulated by the scope. The instrument can also demodulate a 16QAM signal in presence of an interfering signal which is 44dB higher in signal power. All demodulation experiments are performed using the Keysight VSA.

The backplane experiments demonstrate the scope’s capability to perform jitter and noise analysis on multi-gigabit serial links. The built-in equalization software suites are used to find the FFE coefficients and those coefficients are used to perform hardware equalization in an FPGA communication link.

Teardown and Repair of an Agilent E4433B ESG-D Synthesized Signal Generator

E4433B

In this episode Shahriar repairs an Agilent E4433B ESG-D Synthesized Signal Generator. This 4GHz unit shows the “UNLEVEL” error for all frequencies and at all output power levels. After a close look at the system block diagram the fault is traced to the main Output RF board.

The Output RF board is equipped with various amplifiers, electronic attenuators, I/Q mixers, heterodyne paths and final PA. By using soldered SMA cables to various points in the signal path, the fault is traced to an internal amplifier chain which is likely made of a MESFET or JFET transistor. Since this part is obsolete, an RFMD GaAs hybrid amplifier is used in its place. The biasing network and matching networks need to be modified to accommodate this change. The repaired unit is then verified for functionality and performance by measuring a QAM constellation output signal.