TSP #269 - Wonderful Complexity of X-Ray Dosimeter Badges! Teardown, Analysis & Theory of Operation
6.7K views
November 1, 2025 8:37 PM
In this episode Shahriar explores the incredible complexity of x-ray dosimeter badges. These badges are critical in exposure safety measurements and are used by millions of professionals. But how do they work? The x-ray image of the badge reveals its internal structure, x-ray energy discrimination techniques as well as the TLD detectors. The end-to-end operation of the badges are discussed in details as well as the measurement methods.
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TSP #268 - Radio Over Fiber Magic! Optical Link Teardown, Characterization & Measurement Techniques
13.3K views
October 31, 2025 3:24 PM
In this episode Shahriar presents a deep dive into direct detection optical links. The video covers a wide range of topics from detailed module teardown, optical semiconductor discussions, free-space optic interconnect, theory of operation as well as comprehensive characterization of the end-to-end system behavior. Key chapters of the video are organized as follows:
00:00 – Theory of operation, block diagrams & instrument architecture
08:48 – Detailed teardown, optical module analysis, high-magnification imaging
24:32 – Optical link characterization, Siglent instrument ecosystem, radio-over-fiber demonstrations
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TSP #267 - Power Supply from Hell! Surprising Repair of the Condor SP1016 Arcade Power Supply
15.4K views
October 10, 2025 2:44 PM
In this episode Shahriar takes a look at a 1984 Condor power supply from an old arcade machine. Multiple repair attempts of this supply had failed. Examining the schematics reveals how easily this power supply can self-destruct if the primary NPN switching transistor would fail.
The power supply arrived with a bag of replacement components including the power NPN device. But something doesn’t seem right with the parts. Taking apart the original and replacement transistor tells us everything we need to know…
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TNP #55 - Lab Upkeep Time! Agilent 3458A 8.5 Digit Multimeter & MSO9404A 4GHz, 20GS/s Scope Repairs
8.9K views
September 21, 2025 9:17 AM
In this quick episode Shahriar performs some regular lab maintenance. Two instrument need attention. The Agilent 3458A is reporting a Nonvolatile Memory Error & and the Agilent MSO9404A is reporting a dead CMOS battery.
Both problems are easily addressed by changing the battery backup. In the case of the 3458A, the calibration content has to be re-programed into the new NVRAM ICs.
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TSP #266 - Agilent 6GHz MXG Vector Signal Generator (N5182A) Teardown, Repair & Frac-N PLL Analysis
13.6K views
September 18, 2025 8:54 PM
In this episode Shahriar repairs an Agilent N5182A MXG Vector Signal Generator. The instrument produces the correct output signal for some set frequencies but reports a Fractional-N Unlock error for others while the output signal completely disappears. The instrument also fails many self-test checks.
The block diagram of the unit is described in details with a measurement strategy to analyze every element of the PLL loop. The band-pass filter banks are isolated and measured with a Siglent network analyzer and are shown to be fully functional. The VCO output amplifiers & doubler are also fully functional and tested using a Siglent spectrum analyzer. The PLL loop is then “overwritten” and manually adjusting the VCO control voltage demonstrates that the oscillator can cover its entire designed tuning range. The fractional-N divider also appears functional for the appropriate input frequency ranges. Finally, although the GaAs phase detector appear functional, it is possible for such a component to slowly degrade where the phase detection gain changes significantly. This custom Agilent part is sourced from a donor board and the instrument now functions across all frequency ranges and passes all self-tests.
The phase noise performance of the unit is verified against the datasheet using an Agilent E5052B signal analyzer with cross-correlation capability.
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