TCP #1 - From Electricity to Liquid Oxygen! Magic of Thermodynamics, Cryocoolers & Oxygen Capture
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In this April 1st episode, The Signal Path enters a new era. We are rebranding to The Chemical Path! We are interested in designing a system which consumes only electricity and produces liquid oxygen. There are several fascinating physics and thermodynamic effects involved to achieve this.
This video dives into the various scientific phenomenon and explores the operation of pressure swing absorption oxygen concentrators, ultrasonic oxygen sensors and Stirling cryocoolers in details.
The demonstrated complete system consumes less than 400W while producing liquid oxygen at a steady pace. The beautiful blue liquid oxygen is verified to be paramagnetic and of course an aggressive oxidizer.
Many thanks to Ilya (https://xdevs.com/) and Ben (https://www.youtube.com/@AppliedScience) for their consulting and support.
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TSP #259 - HAROGIC SAE-200 Real-Time 20GHz Portable Spectrum Analyzer Review, Teardown & Experiments
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In this episode Shahriar takes a detailed look at the "pocket-sized" HAROGIC real-time 20GHz spectrum analyzer. With its 100MHz of analysis bandwidth and FPGA based signal processing, it is both powered and operates from USB-C ports:
https://rf-instruments.eu/products/sa-series/sae-200/
This review is organized as follows:
00:00 - Introductions
00:36 - Instrument overview, ports and interfaces
02:09 - Performance metrics & data-sheet details
05:39 - Complete teardown with analysis of all RF & digital boards
18:23 - Overall instrument architecture, signal & data paths
19:14 - GUI overview, purity, phase noise measurement, front-end & dynamic range
25:17 - Spurious tone, spectral purity & harmonic rejection in sweep modes
28:18 - Third order intercept, input linearity, IM3 measurement & optimization
32:10 - Real-Time mode, frequency hopping detection, plot persistence & spectrogram
35:58 - AM modulation, pulse/power detection & triggering modes
39:25 - I/Q streaming mode, modulation analysis, power versus time & I/Q versus time
47:49 - Additional features & API interface benefits
48:31 - Concluding remarks
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TSP #258 - TEGAM AVM-2000 100nV - 1000V Null Detector / Nanovoltmeter Repair, Teardown & Experiments
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In this episode Shahriar takes a look at a faulty PPM (TEGAM) Null Detector. With its massive dynamic range (10 orders of magnitude!) this instrument is capable of nano-Volt range measurements. Unfortunately the unit is faulty and does not display or measure anything at the input.
The unit requires a battery for operation (6V Lead-Acid) which can be bypassed by using a 7.4V LiPo battery. The unit powers on and the power supply section is fully functional. Detailed block diagrams and schematic analysis of the unit is discussed during the video.
The analog front-end is also verified to be functional through internal measurements and although there is digital communication between the various internal modules, the ADC only transmits a fixed (faulty) data sequence to the front-panel. The fault is traced to be a corrupted firmware which the manufacture does not agree to share.
Thanks to a helpful internet friend, firmware from a working unit is extracted and compared with the faulty instrument. It becomes clear that the corrupted FLASH memory is responsible. After transferring the calibration coefficients to the modified new firmware the unit comes back to life! Several measurements showcase the units capabilities and functionality.
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TSP #257 - Siglent SNA5000A 8.5GHz 4-Port VNA Mixer & TDR Application Review & Experiments (II)
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In this episode Shahriar continues the review of the Siglent SNA5000A series vector network analyzer. You can also watch the Part 1 review & teardown of this instrument:
https://youtu.be/6vHX0moZUFg
The Siglent SNA5000A continues to receive new features and upgrades:
https://siglentna.com/vector-network-analyzer/sna5000a/
This review is organized as follows:
00:00 - Introductions
02:12 - Scaler Mixer Measurement application & setup
07:33 - Mixer s-parameter & power calibration routines
11:14 - I/Q down & up-converter frequency response characterization
16:01 - Power sweeps and conversation gain implications
19:32 - Frequency doubler measurement setup & characterization
23:07 - TDR measurement application, setup & calibration
26:24 - Characterization of a SATA backplane differential channel
29:13 - Eye diagram plots, data-rate, PRBS & mask setup
32:23 - Equalization, pre-emphasis, jitter & CTLE
36:10 - Concluding remarks
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TSP #256 - Mysteries of Optical HDMI Cables - Tutorial, Teardown & Analysis of Inexpensive Optics
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In this episode, Shahriar takes an in-depth look at the design and architecture of optical HDMI cables, which significantly extend the reach of traditional HDMI 2.0 twisted-pair copper links at a low cost.
The fundamentals of HDMI high-speed data transmission are explored, with a focus on the TMDS (Transition Minimized Differential Signaling) standard. The challenges of transitioning from twisted pairs to optical lanes are examined, highlighting the role of VCSELs and PIN photodiodes. Optical modules are analyzed in detail, emphasizing free-space optics and optical confinement techniques used with lasers and detectors. The received high-speed lane's eye diagram is captured, and the VCSELs' optical wavelength is confirmed to be 850 nm.
Additionally, the TX (driver) and RX (TIALA) chips are inspected under a microscope, revealing the VCSEL and photodetector arrays. The overall electronic architecture is then discussed in greater detail.
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TSP #255 - Terahertz Material & Dielectric Characterization - EM Labs 330GHz Fabry-Perot Resonator
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In this episode Shahriar takes a look at a terahertz characterization technique using a Fabry-Perot resonance chamber made by EM Labs:
https://www.emlabs.jp/en/1-8-fpr.php
The chamber is able to measure dielectric constant and loss tangent with remarkable accuracy and prevision, ideal for materials with tan δ (Df) of 0.01 or less. This tutorial and review video is organized as follows:
00:00 - Introductions
00:45 - Dielectric Constant theory, equations and practical importance
04:54 - Measurement techniques using S-Parameters and resonance chambers
08:16 - Fabry-Perot resonator techniques for accurate Dk & Df measurements
11:04 - THz measurement setup including Fabry-Perot resonator, Keysight Streamline VNA and VDI frequency extenders
13:36 - Design challenges and features of the EM Labs Fabry-Perot resonator
16:02 - Software setup, resonator calibration and preparations
19:22 - Preparing, aligning and measuring samples, organic PCB laminate and prepreg
23:19 - Measuring ultra-low loss materials in J-Band
24:21 - Analyzing anisotropic material properties as a function of orientation
26:27 - Concluding remarks
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TSP #254 - X-Ray Florescence CMI900 Oxford Instruments Teardown, Repair & Experiments (Part 1)
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In this episode Shahriar takes a look at an X-Ray florescence machine. The CMI900 Oxford Instruments unit is not only capable of elemental analysis and identification, it can also measure the thickness of various coatings which is particularly interesting for electronics.
Unfortunately the already-non-functional unit has been further damaged in transit due to poor packaging. In this first video we dive into the repair of the unit and accompanying PC. The unit has several problems both mechanical & electrical and the damage to the PC hosting the unique interface software is also extensive. The teardown and repair procedures are covered in this video.
Stay tuned for the next episode where Shahriar will cover the theory of operation as well as range of measurement experiments.
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TNP #53 - Ω-Source Electronically Controlled Resistance Decade Box Repair, Teardown & Experiments
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In this episode Shahriar takes a look at an interesting electrically controlled resistance decade box. The unit uses a large grid of latching relays to synthesize a wide range of resistance values from fixed surface mount resistors.
The unit has a faulty LCD screen which can be easily replaced. The repaired unit is calibrated using a Keithley 2002 8.5-Digit multimeter and meets is specifications. The resistance box is combined with an adjustable voltage regulator to realize a tunable voltage source with ease.
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TSP #253 - Keysight 256GS/s, 80GHz Bandwidth M8199B 2-Channel AWG Overview, Teardown & Experiments
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In this episode Shahriar takes a look at another world's first instrument: Keysight M8199B 256 GSa/s Arbitrary Waveform Generator. With over 80GHz of analog bandwidth, this high performance ARB is intended for design development at 160GBaud and above:
https://www.keysight.com/zz/en/product/M8199B/m8199b-256-gsa-s-arbitrary-waveform-generator.html
This video is organized as follows:
00:00 - Introductions
00:54 - ARB comparison, performance metrics, key parameters
03:59 - DAC design, chip layout, system level considerations, overall instrument architecture
14:42 - M8199B interfaces, detailed teardown, sub-block overview, output module analysis
30:14 - Demonstration setup, M8199B, DCA-X, 120GHz remote sampling use-case
33:29 - Software interfaces, I/Q tools, signal generation & calibration
36:29 - DCA-X eye-diagram captures, 64GBaud to 200GBaud, NRZ, PAM4, PAM8
44:09 - Keysight captured eye diagram & ultimate system performance
45:50 - Concluding remarks
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TSP #252 - Mini-Circuits 37dBm 1GHz Power Amplifier Repair, Teardown & RF Characterization Tutorial
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In this episode Shahriar takes a look at benchtop power amplifier unit from Mini-Circuits. The amplifier operates from 0.5 - 1000MHz and can provide over 4W of saturated output power. The amplifier is not functional and provides no gain or output power.
The teardown reveals the "hand-made" nature of the multi-stage RF amplifier inside. Although the internal power supply is functional, none of the five internal RF stages have any supply voltage. The problem is traced to a broken small fuse soldered to the main PCB. A new fuse holder is installed.
The amplifier is extensively characterized for frequency response, Psat, P1dB, OIP3, NF as well as efficiency. Details of measurements techniques for each parameter is discussed in details.
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TSP #251 - Agilent 50GHz PSA (E4448A) Spectrum Analyzer Teardown, Repair & Experiments (Part 1)
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In this episode Shahriar takes a look at the faulty Agilent 50GHz spectrum analyzer which does not power on. After tracing the issue and restoring the bootting sequence, it is clear that the instrument has several other issues. The attenuator step calibration failure is addressed which clears all startup errors. However, the instrument still does not measure some frequency bands correctly which points to a failure in the band-selection & mixer assembly. We will have to return to this instrument again in Part 2!
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TNP #52 - A Faxitron MX-20 TruFocus X-Ray Tube Teardown & Analysis
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In this episode Shahriar tales a close look at a defective X-Ray tube from a Faxitron MX-20 x-ray machine. The tube overloads the high-voltage power supply and does not produce any x-ray. The protective mold is removed from the tube to reveal its inner design. The glow of the heating element is also shown.
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