In this world exclusive episode, Shahriar visits Teledyne LeCroy to take a close look at the operation, teardown and experiments with the LabMaster 10-100zi, 100GHz simultaneous bandwidth, 240GS/s real-time oscilloscope. This instrument provides either a single 100GHz channel, or two 33GHz and one 65GHz digitizing channels. The instrument uses a frequency interleaving technique invented and implemented at LeCroy.

The block diagram and the theory of operation of the scope is presented. This includes the architecture of the 4x80GS/s ADCs and the triple frequency interleaving system. The teardown of the scope includes a close look at the ADC platform, the dual frequency interleaving (65GHz operation) and the triple frequency interleaving (100GHz operation). The experiments with the scope demonstrate the instrument's capability to digitize signals up 100GHz using the beat frequency of two non-coherent lasers. The scope is also used to capture a 4pS rise time pulse from a femtosecond laser pulse system and a high-speed photo detector.
A complete factory tour is also presented where Teledyne LeCroy assembles all their oscilloscope products right here in the USA.

The Signal Path
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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.

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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.

https://www.keysight.com/us/en/products/oscilloscopes/infiniium-real-time-oscilloscopes/infiniium-s-series-oscilloscopes.html

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.

The Signal Path Blog
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In this episode Shahriar attempts a repair of an Agilent E3642A DC Power Supply which is completely non-responsive. After presenting a teardown of the power supply, the GPIB interface is used to verify the functionality of the power supply. The problem is traced to the main display unit which communicated with the main power supply via a serial interface.

After disassembly of the display, it is revealed that the entire unit has suffered a catastrophic failure due to the VFD display drive IC. All components must be individually removed and replaced. Unfortunately the main processor is a Mask ROM IC version (80C51) and cannot be sourced. Can you help Shahriar find a replacement part?

The Signal Path Blog
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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.

The Signal Path Blog
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