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TSP #218 - JouleScope JS220 Precision Energy Analyzer Scope Review, Teardown & Experiments

8.1K views December 4, 2022 10:18 PM

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In this episode Shahriar takes a close look at the new JouleScope JS220 dynamic energy analyzer:

The USB-C instrument architecture and details teardown is presented alongside the main PCB X-Ray images. The instrument's unique six orders of magnitude current measurement and switching networks is also described and analyzed. The measurements confirm the six unique shunt resistors (alongside pairing CMOS devices) which can be chosen both manually and automatically by the autorunning software.
The GUI multimeter view is used to verify the accuracy of the unit across all current ranges and voltage ranges using a pair of Keithley 2450 SMUs. The dynamic behavior of the instrument is presented using a wide dynamic range load using various excitation waveforms and frequencies. Finally, a Z-Wave IoT motion sensor characteristics and communication patters is analyzed.​​​

TSP #217 - Teardown, Repair & Analysis of an Agilent E8267C 20GHz PSG RF Vector Signal Generator

9.9K views November 28, 2022 10:07 PM

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In this episode Shahriar attempts the repair of an Agilent PSG Vector Signal Generator. Aside from excellent RF performance, the PSG series generators are also equipped with built-in baseband generators allowing for a wide range complex RF modulations. The instrument has been loaned to The Signal Path by AllTest:

This particular unit fails the internal I/Q Calibration routines. This routine calibrates for image rejection, LO rejection as well as a wide range of I/Q routing, offsets, gain/phase corrections. The calibration errors points of the I/Q MUX board and the summing nodes inside that assembly. The measurements confirms that the Q signal exhibits large distortion.

The teardown reveals the complexity of the I/Q MUX board which comprises numerous op-amps, selectors, amplifiers & multiplexers. The block diagram of the I/Q mux is presented in details along with various measurements. The fault on the I/Q MUX board is traced to one multiplexer on the Q path. The IC is replaced and the waveforms return to their linear forms. The instrument passes the internal I/Q Calibration routine after the repair. The RF output of the unit is also verified and presented showing the correct operation of the vector modulation path.​​​

TNP #24 - Teardown & Experiments with the Melles-Griot Triple-Channel Piezoelectric Controller

9.3K views November 19, 2022 11:16 PM

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In this episode Shahriar presents a three channel Melles-Griot piezoelectric controller which can be used in conjunction with piezoelectric actuator for exceptionally precise movements. The instrument is capable of producing three independent voltages up to 75V per channel. In addition, the unit can use external SUM/DIFF analog signals and adjust the output voltages accordingly.
The instrument is used with a Thor Labs XYZ stage to achieve sub-micron movement accuracy and control. The reverse effects also shown where a mechanical shock to to the XYZ stage produces pulses of voltage.​​​

TSP #216 - Detailed RFIC Analysis of the Analog Devices GaAs 81-86GHz I/Q Direct Down-Converter MMIC

11.2K views November 12, 2022 10:02 PM

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In this episode Shahriar reverse engineers an ADI GaAs 81-86GHz I/Q Down-Converter MMIC. The receiver includes a x6 LO multiplier chain and direct-down-conversion architecture based on pHEMPT single-balanced mixers using fundamental LO frequency.
The RFIC block diagram & die are examined in detailed. The live microscope images are annotated with signal flow drawings to describe various implemented blocks and IC functions.​​​

TSP #215 - R&S NRP Triple-Diode, NRQ6 Frequency Selective Power Sensor & NRX Power Meter Review/Exp.

8.4K views November 6, 2022 9:29 PM

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In this episode Shahriar looks at the ecosystem of R&S power sensors & power meter. In particular, the NRP Triple-Diode Path Power Sensor & the unique NRQ6 Frequency Selective Power Sensor:

The R&S NRX Power Meter can be used to interface with a wide range of power sensors as well:

This review is organized as follows:
00:00 – Introductions.
00:40 – NRP40SN 3-Path Diode Power Sensor hardware overview.
01:21 – Triple-Diode sensor architecture, benefits, principle of operation.
05:59 – Experiment setup, AM modulation glitch, web interface design, power measurements, high-sampling rate, trigger setup, trace view, R&S Power Viewer windows software.
16:17 – NRQ6 Frequency Selective Power Sensor hardware overview.
17:10 – NRQ architecture, principle of operation, advantages & disadvantages, DSP functions.
21:51 – Experiment setup, multi-frequency signal generation & interference, blocker signals.
23:33 – Web GUI interface, Signal Check function, auto-set, IF BW setup, I/Q, trace view, attenuation & averaging, blocker signal impact, catching frequency hopping events, ACLR measurements, additional features.
37:19 – NRX Power Meter overview & teardown.
40:49 – Experiment setup, input VSWR & power amplifier output power measurement.
40:01 – NRX GUI, multi-sensor measurement, sensor setups & measurement features.
45:48 – Concluding remarks.​​​

TNP #23 - Teardown, Repair & Analysis of a Tektronix THDP0200 ±1.5kV High Voltage Differential Probe

12.1K views October 17, 2022 10:24 PM

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In this episode Shahriar repair a Tektronix high voltage probe. The probe is incorrectly identified when plugged into a TekVPI interface and causes the scope to freeze and fail communication with the probe firmware.
With the help of the firmware of the probe is compared with a known good probe.

The probe contains two different microprocessors to handle various probe functions and configurations. The new EEPROM content corrects the problem and points to some interesting conclusions on how the probe is identified by the scope. Measurements confirm the probe is now functional.​​​

TNP #22 - Carl-Zeiss Axioskop 2 LED Retrofit Revisited & Bright/Dark Field, Polarization Microscopy

8.2K views October 8, 2022 4:53 PM

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In this episode Shahriar returns to the microscope LED upgrade challenge. The highest light density LED is used as a point source to improve Kohler illumination. Both transmission & reflected light sources are upgraded while maintaining the control purely through the microscope controls. The LED used can be found here:

Several images are also presented using bright field, dark field as well as polarization manipulation.​​​

TNP #21 - Teardown, Repair & Experiment with Stanford Research SR630 16-Channel Thermocouple Monitor

8.4K views October 6, 2022 9:15 PM

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In this episode Shahriar takes a look at a Stanford Research SR630 16-Channel Thermocouple Monitor. This instrument provides accurate temperature readings multiplexed from 16 unique inputs. It also supports a wide range of thermocouple types. The instrument is purposely not powered on initially as it is prone to capacitor leakage on the main board. The capacitors have destroyed many of the crucial traces all of which have to be individually replaced with wires.
Repair is successful and the instrument is back to life! To test the unit, the temperature on both surfaces a Peltier cooler is measured. The thermoelectric pump is able to cool one side to below -5C while consuming 3.5W.​​​

TSP #214 - What is a good RF cable? Theory & Experiments with Junkosha Phase/Amplitude Stable Cables

29.5K views September 18, 2022 10:15 PM

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In this episode Shahriar discusses the engineering challenges associated with making good RF & mm-Wave cables. The significance of the connector, cable frequency range, loss, phase/amplitude stability & temperate are all examined from a theoretical & practical aspects.

The stability of Junkosha cables are demonstrated up to 50GHz through S11 & phase measurements. The Junkosha MWX7 series cables offer optimized PTFE dielectrics as well as some of the best phase/amplitude/temperature stable operation:​​​