TSP #104 - Siglent SSA3032X 9kHz - 3.2GHz Spectrum Analyzer / TG Review, Teardown & Experiment The Signal Path 2026-09-25 | TSP #104 - Siglent SSA3032X 9kHz - 3.2GHz Spectrum Analyzer / TG Review, Teardown & Experiment
TSP #219 - Teardown & Repair of an Agilent 81101A 50MHz 20Vpp Pulse Generator The Signal Path 2022-12-18 | In this episode Shahriar takes a close look at an Agilent pulse generator which does not produce any output signal. The generator has an output ON/OFF function which can disconnect the unit using a microwave relay. The output spectrum of the faulty unit shows the presence of the desired spectrum and residue of the square wave signal.The teardown shows that the output relay is not being engaged with the output is enabled. The fault is traced to the relay switch transistor (NPN) which does not respond to the control signal. The replacement NPN corrects the problem and the unit produces the correct output. The unit's maximum output swing as well as frequency accuracy are verified using a R&S MXO-4 Series & a Rubidium frequency counter.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #25 - Teardown & Repair of a Keysight E36313A Triple Output Programmable DC Power Supply The Signal Path 2022-12-11 | In this episode Shahriar repairs a broken Keysight E36313A with a blown fuse and burnt smell coming from the unit. The teardown shows the dual-board design of the unit as well as the large toroidal transformer. The magic smoke has escaped from a dual Schottky diode power device with a Vf = 0.45V at If = 5A. The replacement eBay component is first verified to meet the specifications and installed in the power supply. The Keysight unit is then tested at a few output voltages and current to ensure proper functionality. www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #218 - JouleScope JS220 Precision Energy Analyzer Scope Review, Teardown & Experiments The Signal Path 2022-12-05 | In this episode Shahriar takes a close look at the new JouleScope JS220 dynamic energy analyzer:http://joulescope.comThe 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.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #217 - Teardown, Repair & Analysis of an Agilent E8267C 20GHz PSG RF Vector Signal Generator The Signal Path 2022-11-29 | 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:alltest.netThis 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.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #24 - Teardown & Experiments with the Melles-Griot Triple-Channel Piezoelectric Controller The Signal Path 2022-11-20 | 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.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #216 - Detailed RFIC Analysis of the Analog Devices GaAs 81-86GHz I/Q Direct Down-Converter MMIC The Signal Path 2022-11-13 | 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.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #215 - R&S NRP Triple-Diode, NRQ6 Frequency Selective Power Sensor & NRX Power Meter Review/Exp. The Signal Path 2022-11-07 | 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:rohde-schwarz.com/us/products/test-and-measurement/rf-and-microwave-power-sensors/rs-nrpxxs-sn-sn-v-three-path-diode-power-sensors_63493-99587.htmlrohde-schwarz.com/us/products/test-and-measurement/rf-and-microwave-power-sensors/rs-nrq6-frequency-selective-power-sensor_63493-533642.htmlThe R&S NRX Power Meter can be used to interface with a wide range of power sensors as well:rohde-schwarz.com/us/products/test-and-measurement/power-meter-base-units/rs-nrx-power-meter_63493-533644.htmlThis 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.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #23 - Teardown, Repair & Analysis of a Tektronix THDP0200 ±1.5kV High Voltage Differential Probe The Signal Path 2022-10-18 | 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 xDev.com the firmware of the probe is compared with a known good probe. xdevs.com/fix/thdp_tmdp/#tekispThe 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.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #22 - Carl-Zeiss Axioskop 2 LED Retrofit Revisited & Bright/Dark Field, Polarization Microscopy The Signal Path 2022-10-08 | 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:digikey.com/en/products/detail/new-energy/XHP70B-00-0000-0D0BP250E-SB01/7428211Several images are also presented using bright field, dark field as well as polarization manipulation.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #21 - Teardown, Repair & Experiment with Stanford Research SR630 16-Channel Thermocouple Monitor The Signal Path 2022-10-07 | 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.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #214 - What is a good RF cable? Theory & Experiments with Junkosha Phase/Amplitude Stable Cables The Signal Path 2022-09-19 | 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:junkosha.com/en/products/EMF-07www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #213 - Teardown, Repair & Analysis of a Keysight 20GHz MXG Analog RF Signal Generator (Part 2) The Signal Path 2022-09-04 | In this episode (Part 2) Shahriar returns to the MXG repair! The awesome engineers at Keysight have provided a replacement for the suspect part! The exchange is not easy due to the component's strict thermal requirements. A method to provide a good thermal & electrical contact is presented. The repaired instrument is verified for functionality. A close look at the complex micro-module is also presented under the microscope with analysis of each sub-component ceramic part & III/V MMIC.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #212 - Siglent SNA5000A 8.5GHz 4-Port Vector Network Analyzer Review, Teardown & Experiments (I) The Signal Path 2022-08-29 | In this episode (Part 1) Shahriar presents a detailed review of the Siglent SNA5000A series vector network analyzer. The Siglent SNA VNA has a frequency range of 9 kHz to 8.5 GHz, with 2- and 4-port models available. Designed to give you instant insight into scattering, differential, and time-domain measurements. Siglent VNAs enables measurements of the Q-factor, bandwidth, and insertion loss filters and feature impedance conversion, movement of measurement plane, limit testing, ripple test, fixture simulation, and adapter removal/insertion adjustments. There are five sweep types: Linear-Frequency, Log-Frequency, Power-Sweep, CW-Time, and Segment-Sweep mode. SNA5000A VNAs also support scattering-parameter correction of SOLT, SOLR, TRL, Response, and Enhanced Response for increased flexibility in R&D and manufacturing applications:siglentna.com/vector-network-analyzer/sna5000aThis (Part 1) of the review is organized as follows:00:00 - Introductions.01:02 - Instrument overview, design, user & RF interfaces.04:27 - Detailed teardown, architecture, RF design & VNA board reverse engineering.18-21 - Calibration, E-Cal compatibility, built-in procedures, initial GUI overview.22:12 - High rejection filter characterization, pushing the dynamic range limit, port-to-port isolation, IF BW, filtering & averaging.28:28 - Characterizing active devices, measurement topology, differential & common-mode responses, power control, waveform comparison, phase & magnitude response.39:07 - Sweep types, power sweep, compression measurements, non-linear DUT characteristics, impedance & Smith charts.44:12 - VNA as RF synthesizer, CW generation, tone purity & power accuracy.45:26 - Concluding remarks.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #211 - Teardown, Repair & Analysis of a Keysight 20GHz MXG Analog RF Signal Generator (Part 1) The Signal Path 2022-08-20 | In this episode Shahriar investigates a failed Keysight MXG RF generator. The instrument shows UNLEVEL for frequencies above 10GHz. The measurements confirm that the instrument fails to achieve the desired output power. The block diagram of the synthesizer is examined in details and potential failure points are identified.The teardown of the instrument and various components are also presented. A detailed description of the multiplier unit is shown along with the PCB X-Ray. Measurements confirm the failure of an Agilent-branded component (doubler + amplifier module). The repair has to be paused for now until a replacement component is sourced.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #20 - Teardown, Repair & Experiments with Stanford Research Systems SR830 DSP Lock-in Amplifier The Signal Path 2022-08-05 | In this episode Shahriar takes a look at a SRS SR830 DSP Lock-in amplifier. The repair of the instrument is fairly simple and provides a quick look at the internal construction of the unit. The instrument is then used for characterizing nonlinearities of a pair of matched diodes in large-signal operation. A Tektronix 4-Series is also used alongside the SR830 in DDC mode to show the harmonic behavior of the DUT in frequency domain. The SR830 is able to discern extremely small variation in temperature between the diodes and the resultant 2nd order harmonic changes in both amplitude & phase.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #210 - Going off-grid! BigBattery RHINO 48V, 14kWh LiFePO4 Battery Review & Experiments The Signal Path 2022-07-31 | In this episode Shahriar takes The Signal Path Lab off-grid! The BigBattery RHINO 48V LiFePO4, 276Ah, 14kWh is combined with a Growatt SPF 6000T inverter to provide 240V split-phase power to the house. You can see the kit used in this video using this untracked, direct link to BigBattery.com:bigbattery.com/products/48v-off-grid-home-rhino-systemThe review of the battery is organized as follows:00:00 – Introductions & considerations.01:33 – BigBattery offerings, battery configurations, battery chemistry, specifications, warranty, etc.05:51 – Battery construction quality, connector & fuse design, mobile cart, attachment options.07:50 – Provided battery cable with Anderson connector, ratings, quality.08:14 – Built-in LCD screen, GUI & BMS access from the battery, phone app & BMS configuration.11:36 – Battery protection, BMS under small loads, BMS disconnect behavior, power reporting.16:08 – Off-grid setup, Growatt inverter wiring & interfaces, transfer switch & AC access.18:28 – Benefits of a boiler setup for battery backup operation.18:59 – Ensuring correct earth-ground & neutral wiring of the backup system.19:52 – Going off-grid! House power measurements, battery discharge behavior.21:27 – Battery charging behavior, balancing, charging battery to maximum level, charge waveform.22:44 – Concluding remarks.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #209 - Teardown, Repair & Analysis of an Agilent 83752A 10MHz - 20GHz RF Synthesized Sweeper The Signal Path 2022-07-22 | In this episode Shahriar takes a close look at an HP 83752A which shows no signs of life. The power supply of the instrument does not produce standby or any other output voltages. The power supply is examined and the startup circuitry is at fault. The problem is traced to a bad startup capacitor for the primary PWM controller. A replacement resolves the issue and the instrument powers on.The instrument however has other issues. An UNLOCK condition is displayed and further testing shows that the frequency output of the instrument below 2GHz is unstable. The overall block diagram of the unit is presented and the fault is logically traced to a potential problem with the reference 100MHz of the hetrodyne block. An X-Ray of the board allows us to reverse engineer the final output amplifier and a faulty NPN is located. A replacement resolves the UNLOCK condition and the instrument is fully functional.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #19 - Teardown & Repair of a Keysight U1253B 50,000 Count True RMS OLED Handheld Multimeter The Signal Path 2022-07-12 | In this episode Shahriar takes a look a Keysight U1253B multimeter with a notorious problem of failed OLED screens. The OLED would degrade and stop working on some of these units. Since the original OLED model is almost impossible to find, replacement OLED would require a protocol translation layer. The replacement module uses an FPGA to achieve this. The teardown of the unit as well as the repaired units are shown. The performance of the instrument is verified using a universal source and an 8.5-digit multimeter.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #18 - Repair & Analysis of a W-Band (75-110GHz) WR-10 12dBm Power Amplifier Module The Signal Path 2022-06-12 | In this episode Shahriar takes a look at a non-functional W-Band (75-110GHz) power amplifier module with WR-10 waveguide ports. A quick inspection reveals a broken DC connector which can be easily repaired. Since a W-Band VNA or source is not available, the amplifier's excess noise is instead measured using an external mixer and a Keysight MXA-B. The noise power spectral density shows the the amplifier is likely functional with the expected noise and gain.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #208 - Tektronix 2-Series 4-Channel 2.5GS/s 500MHz MSO Review, Teardown & Experiments The Signal Path 2022-06-07 | Is this episode Shahriar takes a look at the brand new 2-Series oscilloscope from Tektronix:tek.com/en/products/oscilloscopes/nextgentekThis review is organized as follows:00:00 - Introductions & overview.01:23 - Instrument interfaces, specifications & design.04:00 - Detailed teardown, instrument architecture & PCB design.12:46 - Input impedance considerations, 50-Ohm passthrough experiment, FFT usage.16:56 - Triggering on infrequent events, runt & pulse detection, advanced triggering usage.21:25 - Detection analog waveform anomalies, high-resolution mode, acquisition control.23:26 - Bus decoding capabilities, packet table viewing, UART decoding.25:56 - AFG functionality, measuring filter responses, arbitrary & noise generation.32:22 - Concluding remarks.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #207 - Teardown & Detailed Analysis of Qualcomms 60GHz Multi-Panel Phased Array WiGig System The Signal Path 2022-05-22 | In this episode Shahriar takes a close look at a wireless-Ethernet product based on Qualcomm's 60GHz WiGig chipset. The episode is inspired by the upcoming in-person RFIC & IMS IEEE conferences held starting June 19th, 2022 in Denver, Colorado, USA:IEEE Radio Frequency Integrated Circuits Symposium:rfic-ieee.orgIEEE International Microwave Symposium:ims-ieee.org/ims2022The entire WiGig system architecture is analyzed end-to-end. The phased array module is presented using x-ray images and individual RFIC's are examined under microscope. www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #17 - Teardown, Upgrade & Experiments with Sencore LC103 Rezolver Capacitor & Inductor Analyzer The Signal Path 2022-05-21 | In this episode Shahriar takes a look at the very rare Sencore LC103 Rezolver Capacitor & Inductor Analyzer. The instrument receives a firmware upgrade (EPROM) as well a thorough cleaning. A brief teardown and main blocks of the unit are also presented. The basic functions of the instrument are verified and checked against the Keysight E4980A. The power supply and leakage capability of the instrument are also verified.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #206 - Keithley 2281S Precision Power Supply & Battery Simulator Review, Teardown & Experiments The Signal Path 2022-05-07 | In this episode Shahriar reviews the Keithley 2281S-20-6. This is a Dynamic Battery Simulator and Precision DC Bench Power Supply with TFT LCD display uses a model to emulate the response of a battery over its discharge cycle. Since the model can be based on the average current of the product that the battery will power, you can estimate battery life and analyze product performance over the life of the battery:tek.com/en/products/keithley/dc-power-supplies/2281s-seriesThe review is organized as follows:00:00 - Introduction.00:35 - Instrument overview, interface, GUI, functions & design.04:08 - Teardown, architecture, components and build quality.10:03 - Precision power supply benefits, short-circuit hunting.14:56 - Time-domain capabilities, pulse measurements, graphing functions, triggering.20:59 - Battery Test capabilities, measuring super capacitors, measuring ESR, battery discharge.26:20 - Creating a battery model during a charge cycle, battery capacity measurements.27:29 - Creating a discharge battery model using the Keithley 2450 SMU.29:32 - Battery Simulator function, battery models, modifying battery limits, stress testing DUT.36:14 - Concluding remarks.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #16 - Teardown, Repair & Analysis of a few mm-Wave (26GHz - 40GHz) Amplifier Modules The Signal Path 2022-04-03 | In this episode Shahriar takes a close look at a few mm-wave amplifier modules which have failed. The amplifiers cover a few frequency ranges up to 40GHz. The measure S-Parameters reveals a serious problem with the amplifiers. The teardown of the module is presented along with microscope closeups of various devices and integrated circuits used in its construction. A broadband amplifier is also examined with a simpler problem. A broken DC power connector is replaced which brings the unit back to life showing 18dB of gain with better than 25GHz 2dB bandwidth.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #15 - The Impossible Amplifier The Signal Path 2022-04-01 | Could I have found the greatest amplifier on April 1st?www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #205 - Keysight FieldFox 50GHz Handheld Microwave Analyzer / RTSA Review & Experiments The Signal Path 2022-03-26 | In this episode Shahriar reviews the Keysight FieldFox Microwave Analyzer which is capable of both 2-port network analysis as well as spectrum analyzer with real-time capabilities. Keysight's FieldFox portable analyzers are equipped to handle tough working environments during routine maintenance, in-depth troubleshooting, and anything in between: keysight.com/us/en/products/network-analyzers/fieldfox-handheld-rf-microwave-analyzers.htmlThis review is organized as follows:00:00 - Introductions.01:22 - Instrument overview, design, interfaces, built quality.04:38 - LCD screen, remote interface, GUI usage.05:04 - S-Parameter personality, calibration, tuner experiment, reflection phase shifter measurements, etc.15:35 - Power Sensor personality, PA load-pull experiment, reflection power measurements. 21:12 - Spectrum analyzer personality overview, built-in synthesizer, output spectrum quality.24:42 - mm-Wave transmitter measurement, detecting impairments, spectrum analyzer capabilities.29:00 - I/Q analyzer personality, RF envelope versus time capabilities.31:33 - Real-time spectrum analyzer personality, 100% POI performance.33:23 - PathWave VSA compatibility, mm-wave constellation demodulation example.36:32 - Noise Figure personality, Friis equation demonstration, NF uncertainty calculator.46:50 - Concluding remarks.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #14 - Teardown & Analysis of a Somewhat Dangerous LiPo-Based Mini Spot Welder The Signal Path 2022-03-14 | In this episode Shahriar takes a look at the a battery-based spot welder which have become fairly popular recently. Due to being mass-produced, some poor corner-cutting schemes can render these devices dangerous. The teardown of a random unit is presented. After improving the safety of the unit, a sample weld is done. The maximum deliverable energy of the unit is also measured.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #204 - Teardown, Tutorial & Experiments with Active/Passive Microwave Band-Pass Filters (APS104) The Signal Path 2022-03-13 | In this episode Shahriar repairs an OPTOELECTRONICS APS-104 tunable band-pass filter. The instrument provides continuous tuning from 20MHz to 1GHz with a constant 4-MHz band pass response. Since the repair proves to be fairly easy, the video focuses on comparison between various band-pass filter architectures. This includes microwave cavity filters, PCB-based filters with varactor tuning, YIG filters and frequency-translation filters. A range of measurements highlight the differences and pros/cons of the aforementioned filters. The APS-104 unit is fully reverse engineered and characterized as well.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #13 - Teardown & Repair of a Keithley 2001 7.5-Digit Multimeter The Signal Path 2022-02-20 | In this episode Shahriar repairs a Keithley 2001 7.5 Digit multimeter. This is a very high performance unit and worth repairing. However, the early 90's revision of these units were subject to electrolytic capacitor failure all overt the analog and digital boards. The failed capacitors destroy the nearby traces including the inner layer connections. The teardown of the unit reveals this problem. By using x-ray imaging the missing and damaged traces are identified and meticulously repaired. Several of the power supply diodes were also destroyed. The repaired unit passes all self-tests as well as measured V/I/R in both DC and AC correctly. The unit is compared with measurements reported by a Keithley DMM7510.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #12 - Teardown, Repair & Experiments with the Fluke 345 Digital Power Quality Clamp Meter The Signal Path 2022-02-06 | In this episode Shahriar repairs a Fluke 345 Digital Power Quality Clamp Meter. The Fluke 345 is more than an electric power meter. Combining the functions of a clamp meter, oscilloscope, data logger and digital power meter into one handy device, the Fluke 345 is ideal for working with variable frequency motor drives, high efficiency lighting and other loads using switching electronics.Although the repair ends up being fairly simple, we get some insight into some of the user interface circuitry as well as some experiments showing the capabilities of the unit.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #203 - Teardown, Upgrade & Experiments with an Agilent 3400B High Dynamic-Range RMS Voltmeter The Signal Path 2022-01-30 | In this video Shahriar upgrades an Agilent 3400B RMS meter to add an LCD-based GUI interface and USB digitization capabilities. This excellent instruments offers high RMS frequency range of 10Hz - 20MHz and can reliably measure 100uV RMS - 300V RMS! The instrument uses purely analog techniques to accomplish this.The theory of operation of the instrument is presented in details along with the challenges of adding digital circuits among such a sensitive analog domain. The upgrades use two modules which communicate through a serial interface and use an ADC to digitize the measured analog RMS value. A new GUI interface is developed to display a wide range of useful information simultaneously as well as historical data trend line. The instrument is used to perform several measurements including measuring the output noise of a DC/DC converter module.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #202 - A Uniquely Complicated Nixie Tube Clock: HP 5245L Electronic Counter & ERA EasySynth++ The Signal Path 2021-12-12 | In this episode Shahriar repairs and analyzes two instruments. An HP 5245L Electronic Counter which uses 1960's technology to achieve some incredible performance. The HP unit uses eight beautiful nixie tubes as its main numeric display. The instrument requires repair, calibration and some upgrades to prepare it for use as a nixie tube clock! The source of the clock is an ERA Instruments EasySynth++ which is a high performance, open-source synthesizer up to 20GHz:erainstruments.comThe architecture and teardown of the EasySynth++ is also presented. The two instruments are combined with some custom scripts to create the world's (?) most complicated nixie tube clock.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #11 - Teardown & Analysis of a 75-110GHz (W-Band) Waveguide mm-Wave Balanced Mixer Module The Signal Path 2021-11-14 | In this episode Shahriar investigates the mysteries of a W-Band fundamental LO balanced mixer module based on GaAs Schottky Barrier Diodes. The mixer offers a very high IF bandwidth of 35GHz and LO driver requirements of 13dBm between 75-110GHz.The teardown reveals the waveguide to coaxial transitions as well as the interface to the pair of Schottky diodes. High resolution microscope analysis provides a detailed view of the precise machined waveguide ports.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #201 - Rohde-Schwarz NGU401 500kS/s Source Measure Unit Review, Teardown & Experiments The Signal Path 2021-11-08 | In this episode Shahriar reviews the latest edition to the R&S SMU family, the NGU401. rohde-schwarz.com/us/products/test-and-measurement/dc-power-supplies/rs-ngu-source-measure-units_63493-1005128.htmlThis instrument offer four-quadrant operation, 60W total output power, 6.5 digit resolution as well as 500kS/s digitizers on both voltage and current readbacks. The instrument also offers a verity of output control and arbitrary waveform generation. This review is organized as follows:00:00 - Introductions00:50 - Front & back panels, interfaces, design02:40 - Detailed teardown & architectural analysis08:36 - Pooch!08:45 - USB Power Bank experiment, NGU GUI design, primary capabilities13:20 - Multi-quadrant operation, sink/source conditions15:49 - High-speed sampling, auto-ranging and transient detection18:29 - Deep-sleep battery drain detection of Fluke 233, graphical viewer, fast logging22:35 - Characterizing a DC/DC converter, transient output current27:19 - High output capacitance mode, oscillation detection29:45 - Current/voltage priority modes30:40 - Fast arbitrary waveform generation, 34:20 - Additional functions, OVP, OCP, OPP, Modulation Input, trigger IOs, slew control, fast transient36:18 - Concluding remarkswww.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #10 - Teardown & Experiments with a Mystery Vintage (1950) Hewlett-Packard Instrument The Signal Path 2021-10-18 | In this episode Shahriar takes a look at an unusual vintage HP instrument from the 1950s. The unit has a vacuum-tube-like core with a pair of banana plug interface.After restoration, the instrument principle of operation, teardown and schematics are presented. Several experiments demonstrate the use-case as well as the correct operation of the unit.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #9 - Teardown & Analysis of an Electronic COVID-19 Home Test Kit (ellume) The Signal Path 2021-10-10 | In this episode Shahriar takes a look at a pair of COVID-19 electronic home kits. These Bluetooth enables devices are manufactured by ellume. Both of these tests had produced false-positive results. The optical readout mechanism of the devices are examined as well as the general design of the unit.This video is not about which COVID-19 home test kit you should purchase. This is an exploration and analysis of this particular device for educational purposes only. For all medical advice regarding COVID-19, please contact your doctor.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #200 - Carvera (Makera) 4-Axis CNC Machine with Automatic Leveling, Tool Changer & Laser Review The Signal Path 2021-10-04 | In this episode Shahriar reviews an ambitious new CNC machine currently offered on Kickstarter. The machine is equipped with automatic tool changer, automatic probing & leveling, built-in dust collection, optional fourth axis and integrated laser engrave module. The review of the pre-production model focuses on the units capabilities along with high-precision PCB experiments. You can access the Kickstarted campaign here:kickstarter.com/projects/makera-inc/carvera?ref=6gzkblThis review is organized as follows:00:00 - Introductions and expectations01:22 - Machine overview, constriction, tablet holder, work area03:23 - Automatic tool changer design & operation04:30 - Automatic probing and leveling system06:11 - Movement mechanism, precision & accuracy, built-in laser, z-axis09:37 - Optional fourth axis module10:23 - Included accessories, bit changer tool, collet tool10:56 - Built-in dust collector11:33 - CNC interface software, G-code, features & work flow15:03 - High precision measurement of the x-axis accuracy & repeatability17:34 - 3.5GHz filter design from Gerber to G-Code, CNC operation21:18 - Filter PCB and high precision examples after CNC, microscope view23:23 - Filter measurements & comparison with simulation24:27 - Homemade oil-bath for FR4 CNC dust protection24:56 - Manufacture example of PCB with solder-mask25:38 - Laser engraving example of photo-realistic sample26:32 - Automatic level & laser engraving of soft materials27:55 - Conclusions & future planswww.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #199 - Digilent Analog Discovery Pro 3000 Series (ADP3450) Review, Teardown & Experiments The Signal Path 2021-09-26 | In this episode Shahriar reviews the Analog Discovery Pro 3000 Series, particular the ADP3450 model. The instrument offers a combination of mixed signal oscilloscope and dual-channel arbitrary waveform generator. The WaveForms free software can be used to perform a wide range of measurements. You can find more information about this product at:digilent.com/shop/analog-discovery-pro-3000-series-portable-high-resolution-mixed-signal-oscilloscopesThe review is organized at follows:00:00 - Introductions00:35 - Instrument overview, functions, specifications and design04:53 - Detailed teardown and architecture overview11:17 - WaveForms software, oscilloscope capabilities, catching glitches, trigger functions19:18 - Mixed-Signal measurements, logic analyzer, cross-domain triggering22:19 - Serial decode, digital trigger, correlated measurements24:03 - Waveform generation, synchronized signals, modulations, sweeps, FFT, 3D spectrogram28:46 - Network analyzer functionality, measuring linearity and frequency response of DUT33:42 - Impedance analyzer functionality, measuring complex impedance across frequency36:29 - Additional capabilities, tracer, scripting, etc.37:39 - Concluding remarkswww.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #8 - Teardown & Detailed Analysis of the U2001A 6GHz Agilent USB Power Sensor The Signal Path 2021-09-05 | In this episode Shahriar takes a close look at the design and architecture of an Agilent USB Power Sensor. The principle operation of different power detectors is presented alongside various block diagrams and schematics. The teardown of the power sensor reveals the system components from the integrated sensor MMIC to the ADI BlackFin DSP core. The detector is further examined under the microscope and the dual-diode detector design is presented.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #7 - Ynvisible Electrochromic Ultra-low Power Segmented Display Technology The Signal Path 2021-08-21 | In this episode Shahriar takes a look at an ultra-low power display technology. The Ynvisible Segment Display is an electrochromic display. It is categorized as a reflective display, meaning that it reflects ambient light instead of using a backlight. All layers are screen printed on a plastic substrate.The display stack consists of organic layers including a plastic substrate, an electrochromic material, an electrolyte, and an electrode for each segment. Additional layers such as graphical overlays and circuits may be added if required.You can find more information about this display technology at:ynvisible.comwww.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #6 - Teardown & Analysis of a Keysight (Agilent) 9GHz Electronic Calibration Module (ECal) The Signal Path 2021-08-15 | In this episode Shahriar analyzes the principle operation of an Electronics Calibration Module also known as ECal. This unit operates up to 9GHz and is one of the earlier models produces by Agilent. The block diagram of the unit is presented as well as a detailed teardown of the RF core assembly. The various built-in standards can be clearly seen as well as the solid-state switch networks which connects them to the network analyzer ports.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TNP #5 - Teardown & Analysis of Damaged Anritsu K250 40GHz & SHF 123B 65GHz Bias-T Blocks The Signal Path 2021-08-14 | In this episode Shahriar takes a look at some mailbag RF components. The set of Anritsu Bias-T blocks all have damaged DC paths. The teardown of the Bias-T shows its internal construction and assembly procedure. The SHF Bias-T offers a much more sophisticated and broadband response. A single Bias-T has survived with only a broken DC connector which is repaired and measured.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #198 - Teardown, Repair & Analysis of an Anritsu MG3700A 6GHz Vector Signal Generator (Part 1) The Signal Path 2021-08-08 | In this episode Shahriar attempts to repair an Anritsu MG3700A Vector Signal Generator. The instrument does not fully power on and suffers from several problems. The digital IF board as well as the main computer are presented. The power-on fault is traced to a faulty fuse on the 5V power supply which feeds the main CPU board. A new fuse enables the instrument to fully boot.The unit also exhibits a failure for all signals above 3GHz. The instrument is equipped with a super hetrodyne mixer board which covers 3GHz - 6GHz output range. This RF board is examined and explored in details alongside the block diagram of the unit. The fault is traced to a unidentifiable component (potentially PIN diode switches). Bypassing these components allows the instrument to generate sufficient power. However, the repair must stop here for now until these parts can be identified.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #197 - Teardown, Repair & Analysis of a Rohde & Schwarz FSL 9kHz - 6GHz Spectrum Analyzer The Signal Path 2021-07-25 | In this episode Shahriar investigates a failed R&S FSL Spectrum Analyzer. The instrument shows an unusual spectrum trace and fails a wide range of self-test functions. The LO Unlock failure is likely the most important item to address which can cause a cascade failure of other functions.The teardown of the instrument shows a single-board RF design. The system architecture is analyzed along with an X-Ray of the main board showing various RF/LO routes and interconnects. The core synthesizer is examined and measured along the signal path to verify the operation of each part. The failure is traced to an open 1-Ohm resistor which feeds the power supply of the divider IC feeding the PFD of the PLL. A ceramic capacitor failure is also observed which may explain the damage to the 1-Ohm resistor. After these components are replaced the instrument passes all self-tests. The functionality of the instrument is verified by measuring tones from 9KHz - 6GHz using a Keysight MXG. www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #196 - Tutorial & Experiments on Tunable Semiconductor Lasers & Wavelength Locking Methods The Signal Path 2021-07-12 | In this video Shahriar dives into the world of tuneable semiconductor lasers. First, a Santec TSL-200 source is presented and repaired. The performance of the instrument is verified using a multi-wavelength meter. A DFB gold box laser module is then presented along with a demonstration showing the sensitivity of the laser diode to temperature variations. The entire wavelength locking mechanism of the DFB laser is presented in details along with the principle operation of an Etalon wavelength interferometer. The teardown of the module shows all its inner workings. The LightSquare product and its teardown is also shown which includes a diffraction wavelength measurement system. Finally the operation of the TSL-200 tuneable semiconductor laser is presented which uses a tuneable external cavity Fabry-Perot laser. Finally the teardown of the multi-wavelength meter is shown along with the operation of the Michelson Interferometer inside.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #195 - Teardown, Repair & Experiments with an Agilent 8163A Lightwave Multimeter & Laser Modules The Signal Path 2021-06-27 | In this episode Shahriar repairs an Agilent 8163A Lightwave Multimeter. The instrument shows a flickering screen and does not boot. The teardown of the unit is presented along with a general instrument architecture. The power supply is verified for functionality and the instrument simply comes back to life on its own! It most likely has had a poor internal connection which is resolved after reassembly.Two modules are also presented, a dual-input InGaAs power sensor module as well as a dual Fabry-Perrot laser module. The teardown and analysis of both are presented along with wavelength and spectrum measurements.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #194 - Teardown, Repair & Experiments with a Marconi 2186 130dB 5GHz Programmable Attenuator The Signal Path 2021-06-14 | In this episode Shahriar repairs an IFR (Marconi) 5GHz programmable attenuator capable of reaching a maximum of 130dB attenuation in 1dB steps. The Instrument does not power on and a teardown reveals some missing components inside. After replacing the missing component, the instrument powers on but the S-Parameters show that the mechanical attenuators have serious contact problems. Finally after cleaning the attenuator contacts, the instrument is fully operational. The unit is used to measure the performance of the Keysight MXR at very low input signal powers.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #193 - Tutorial & Experiments with Keysight E4980A 20Hz - 2MHz Precision LCR Meter The Signal Path 2021-06-05 | In this episode Shahriar describes the subtle internal operation of the Keysight E4980A precision LCR meter. This 0.05% grade instrument offers measurement frequency range between 20Hz - 2MHz with a wide range of advanced functions such as binning, internal DC source, internal bias control as well as extreme dynamic range across the entire frequency span.Several test fixtures are presented with accompanying measurements. Lastly, a simple parallel plate capacitor is measured to demonstrate the effect of various dilectric materials on the total capacitance.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #192 - Teardown & Repair of a Rohde & Schwarz FSV40 9kHz - 40GHz Spectrum Analyzer The Signal Path 2021-05-29 | In this episode Shahriar repairs a R&S FSV40 spectrum analyzer which despite passing all self-tests and alignments, shows all inputs signals heavily attenuated. The instrument block diagram is reviewed as well as a quick teardown. The problem is traced to a faulty front-panel connector which unfortunately doesn't make for an exciting repair. Nevertheless, the connector is repaired and the instrument returns to normal operation.Thank you AllTest for providing this instrument for repair! You may see various products and services offerings from AllTest here:Alltest Instruments: alltest.netProvides: Refurbished benchtop test & measurement instrumentation, service, and calibration. Types of equipment include but are not limited to oscilloscopes, network analyzer, spectrum analyzers, signal generators, multimeters, etc.Alltest Chambers: alltestchambers.comProvides: Refurbished environmental test chambers, service, and calibration. Types of equipment include but are not limited to hot, cold, shock, altitude, liquid, HALT/HASS, temperature forcing, etc.Brerro Technical Consultants: https://brerro.tech/Provides: Expert consultation creating low cost solutions related to R&D, engineering, manufacturing, QA/QC, and compliance. Solutions include but are not limited to EMI/EMC testing, SMT and PCB applications, MIL-461 compliance systems, MIL-810 compliance systems, DO-160 compliance systems, manufacturing equipment and systems.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
TSP #191 - Teardown, Repair & Experiments with a GW-Instek APS-1102 Programmable AC/DC Power Source The Signal Path 2021-05-27 | In this episode Shahriar takes a look at a GW-Instek programmable AC/DC source with 1kVA, 200V capability. The instrument is ideal for power applications since it offers customized waveforms as well as AC+DC output. The unit shows COMMUNICATION ERROR 2 when powered which indicates an internal module-to-module fault. An X-Ray of the main processor board shows the various power supply planes and isolated sub-components communicating through optocouplers. The power supply design is reverse engineered and the fault is traced to a set of bad operational amplifiers. All broken components are replaced which restores the unit's functionality. The instrument is then tested to show some of its capabilities.www.TheSignalPath.comwww.YouTube.com/TheSignalPathwww.Patreon.com/TheSignalPath
