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.
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?
In this episode Shahriar compares the performance and features of the Siglent SDG5162 and Rigol DG4162 Arbitrary Waveform Generators. Siglent has recently opened a new North America office which would certainly help them bring their instruments to the US more quickly and provide better local customer and sale support.
The Siglent SDG5000 teardown is presented. Aside from various GUI features of these two units, the THD, phase noise and maximum output power of each unit is measured. The ability of the Siglent generator to produce 12ns pulse width independent of the output frequency is also presented with some practical applications. Finally the Easy Wave application us is used to generate some custom waveforms.
In this episode Shahriar repairs an Agilent 33250A function and arbitrary waveform generator which does not power on. The unit is equipped with a soft power switch which might be responsible for the fault. After a brief look at the unit’s constructions, the fault is traced to a few possible locations.
The schematic of the soft power circuitry is presented and the internal switching power supply is closely examined. After the fault is located, the repair is presented. The block diagram and operation of a current mode DC-DC switching IC is also presented.
In this episode, Shahriar upgrades a Verity visible wavelength monochromator model EP200Mmd to be able to perform automatic scans. The instrument is retrofitted with a stepper motor and a microcontroller which performs wavelength scanning between 225nm to 875nm. The signal from the internal photomultiplier is sampled by the microcontroller and wirelessly sent to the computer. Matlab is used to plot the wavelength response.
The principle operation of a monochromator is thoroughly reviewed starting with the grating mirror behavior. The operation of the photomultiplier is also described. Various mechanical and electronic of the upgraded system is also shown. The presented slides can be found here.