TSP #267 - Power Supply from Hell! Surprising Repair of the Condor SP1016 Arcade Power Supply
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61 minutes ago
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
8.2K views
September 21, 2025 10:17 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
12.8K views
September 18, 2025 9:54 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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TSP #256 - Thermal Camera Cooled to -196C! Cryogenic HgCdTe (MCT) Long-Wave Infrared Detector Magic
14.9K views
August 19, 2025 10:21 PM
In this video Shahriar dives into the amazing science & engineering of cryogenically cooled thermal cameras. This particular model, Inframetrics 760 Imaging Radiometer, was manufactured in the 1990’s and leverages a range of clever engineering techniques. It includes a miniaturized Stirling engine cryocooler, galvanometer based mirrors for 2D field scanning as well as a low-noise Mercury-Cadmium-Tellurite (HgCdTe) MCT detector sensitive in the 4-15um wavelength.
Teardown of the unit along with a detailed theory of operation is presented. The semiconductor profile and properties of MCT detectors are also discussed. Furthermore, a different thermal camera using a Joule-Thomson cryocooler and high-pressure (3000 PSI) Argon source is also shown.
After reverse engineering the critical detector interfaces, an experiment is devised to measure the thermal signature of a resistor. The setup includes a triangle wave driving a resistor to generate a time varying thermal source, Lakeshore M81 source-measure lock-in amplifier and chopper in front of the MCT detector and BLDC motor driver for running the cryocooler. The measurement demonstrates the functionality & sensitivity of the detector to capture black body radiation.
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TNP #54 - How Much Does YouTube Pay The Signal Path? Also Oscilloscope Giveaway Time!
14.6K views
August 2, 2025 11:10 PM
In this episode Shahriar shares the total ad revenue of The Signal Path since its inception in May 2011.
There is also another oscilloscope giveaway! This time it will be a Siglent SDS1000X HD, 4-Channel Oscilloscope. The winner will be randomly selected in one month.
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