TNP #39 - Faxitron MX-20 Digital Micro-Focus X-Ray Machine Teardown, Repair & Experiments
28.3K views
September 17, 2023 4:16 PM
In this episode Shahriar repairs his Faxitron MX-20 digital x-ray system. Although the machine has been producing beautiful images for years, recently it has been outputting out-of-focus images intermittently.
The principle of x-ray focusing and beam-spot generation is presented along with potential electronic methods of achieving focus. The teardown of the unit reveals the main x-ray tube controller PCB which houses the focus control high-voltage modules. Since the problem is intermittent, a reed switch is also suspected. The high-voltage module is measured and appears fully functional. Replacing the reed switch corrects the out-of-focus images. Several x-ray images showcases the sharpness of the unit after the repair.
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TSP #232 - Near-THz Sub-Harmonic Mixers (Tektronix 75 - 140GHz) Tutorial, Teardown & Experiments
32.2K views
August 12, 2023 8:05 PM
In this episode Shahriar takes a deep dive into near-THz sub-harmonic mixers. To demonstrate the concepts, measurements and teardowns a set of Tektronix Sub-Harmonic mixers have been acquired (WM 490-F & WM 490-W) which operate from 90-140GHz & 75-110GHz respectively. This video is organized as follows:
00:00 – Introductions
00:50 – Acquired near-THz sub-harmonic mixers & diplexers
01:26 – Theoretical background, non-linear devices, harmonic generation
06:05 – Spectrum analyzers utilizing sub-harmonic mixers, signal ID
08:27 – Tektronix sub-harmonic mixer design, schematic & principle of operation
15:11 – Mixer diode characterization using Keithley SMUs & I/V tracer application
19:59 – Mixer teardown, analysis and microscope view of THz diode
28:07 – Diplexer architecture & characterization using a 4-port Siglent network analyzer
33:24 – Complete near-THz down-conversion setup using a x6 mm-wave multiplier source and Tektronix MSO68-B oscilloscope, conversion loss, harmonic number verification, signal ID process
45:35 – Using a ~100GHz carrier to determine the RPM of an optical chopper
48:15 – Concluding remarks
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TSP #231 - Sanko BN100+ 300kHz - 6.5GHz USB Vector Network Analyzer Review, Teardown & Experiments
19.4K views
August 7, 2023 7:28 PM
In this episode Shahriar reviews the Sanko BN100+ USB vector network analyzer which has been designed in partnership with Bird RF:
https://www.sankorf.com/products/bn100-plus
The review is organized as follows:
00:00 – Introductions
00:27 – Instrument front & back panels
02:15 – Teardown, internal architecture, front-end coupler design
06:03 – Firmware distribution
06:36 – VNA output signal performance, sweep types, sweep speed, harmonics (THD), power sweep
14:00 – Calibration, built-in models, calibration procedure & standards
15:35 – Port to port isolation, noise floor, minimum detectable response
16:18 – Extreme filter dynamic range measurements
18:07 – VGA measurements, dynamic s-parameters, trigger in/out
24:11 – Time domain analysis, impulse response measurements
26:27 – Frequency accuracy measurements
27:01 – Concluding remarks
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TSP #230 - A Real-Life Tricorder! Agilent Raman Resolve Through-Barrier Chemical Analyzer
34.9K views
July 20, 2023 7:49 PM
In this episode Shahriar takes a close look at the Resolve Handheld Raman Analyzer for Chemical Identification from Agilent. This instrument resembles a real-life Tricorder with its ability to identify chemicals through various opaque containers.
https://www.agilent.com/en/product/molecular-spectroscopy/raman-spectroscopy/handheld-raman-chemical-detection-systems/resolve-handheld-raman-analyzer-for-through-barrier-chemical-identification
This video explores every aspect of this instrument’s design from principle of operation to the modern electronics required to realize its function. The video is organized as follows:
00:00 – Introductions & first through-barrier scan example
02:46 – Raman history, invention & Nobel prize
04:41 – Infrared absorption, Raman spectroscopy theory, challenges and importance of fluoresce
10:49 – Fluorescence example & measurement using Uranium glass & HeCd laser
15:21 – Other applications of fluorescence such as microscopy
16:48 – Nonlinear optical effect and frequency doubling crystals, measurement of green laser
20:13 – Other applications of nonlinear optics, autocorrelation instrument to measure femtosecond pulses
23:18 – Electron excitation of atoms to produce photon emissions using Helium & Neon gasses
24:23 – Components required to build a Raman spectrometer
25:15 – Monochromator & spectrometer architectures, limitations & design
29:07 – Agilent Raman Spectrometer overall architecture, Raman chemical fingerprints
31:10 – Spatially Offset Raman Spectroscopy (SORS) theory & application
32:43 – Agilent Raman Resolve use-cases, accessories and application scenarios
36:03 – Measurements & identification of spilled unknown powders & liquids
40:53 – Through-barrier plastics & glass measurement of mixed liquids & acids
42:52 – Agilent Resolve extensive library & material categories, Reach-back support
44:03 – Chemical identification examples using the Vial accessory
47:26 – Trace chemical concentration & sensitivity measurement
48:34 – Concluding remarks
Data TNG image credit:
https://www.startrek.com/article/cosplaying-data-star-trek-next-generation
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TNP #38 - SourceTronic ST2516 Micro-Ohm DC Resistance Meter Teardown, Modifications & Experiments
21.4K views
July 6, 2023 9:31 PM
In this experiment Shahriar modifies a SourceTronic DC resistance meter due to its incredibly loud built-in buzzer. The instrument can sink up to 1A through a DUT and therefore measure down to micro-ohm resolution. The instrument also has offset voltage compensation capability to eliminate thermoelectric effects from bimetal contacts to the DUT. A direct measurement of the DUT current shows how the instrument is able to do this task in the background while measuring low resistances.
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