TNP #43 - Rohde & Schwarz URE2 DC - 25MHz 300V RMS Voltmeter Teardown, Repair & Experiments
14.2K views
November 23, 2023 7:46 PM
In this episode Shahriar takes a look at a fault Rohde & Schwarz URE2 which is a highly sought after RMS voltmeter. The ability of the RE2 to provide accurate RMS measurement up to 25MHz as well as provide DC measurement makes it an excellent instrument for characterizing DC/DC converter output noise characteristics.
The faulty instrument can measure AC, however no DC measurement can be made. The unit also occasionally generates an error code 0080 which points to a fault in the main analog board. Teardown of the instrument reveals a pair of front-end relays responsible for mode switching which are the likely cause of the DC measurement problem. The relays are replaced and the instrument returns to full operation. The performance and functionality of the unit is verified through several experiments.
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TNP #42 - Combustion Gas & Emissions Analyzer E1500 (O2, CO, CO2) Repair, Teardown & Experiments
11.3K views
November 18, 2023 3:24 PM
In this episode Shahriar explores the technology behind combustion gas analyzers. These instruments are capable of measuring the concentration of various gasses such as O2, CO, CO2, NO2, SO2, etc. The particular unit shown in this video (E-Instruments E1500) is capable of holding two sensors.
The end-of-life Oxygen sensor is replaced to bring the unit back to life. The teardown of the instrument as well as the faulty Oxygen sensor are presented along with Raman chemical analysis of the sensor electrolyte. The biproduct of a burning candle as well as a HotHands hand warmer are analyzed using the instrument.
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TNP #41 - Stanford Research SR620 Universal Time Interval Counter Teardown, Repair & Experiments
21.8K views
November 17, 2023 2:09 PM
In this episode Shahriar repairs an SRS SR620 frequency interval counter where the magic smoke has escaped! The instrument does not power on and the teardown reveals a burnt resistor. The circuit examination shows a voltage regular for the 5V output which has a short circuit the the chassis. A simple repair and resistor replacement brings the unit back to life.
The performance of the internal OCXO is measured against a Rubidium oscillator and the unit is frequency calibrated. The XY output mode of the unit as well as its ability to measure propagation delays are also shown.
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TNP #40 - Stanford Research FS735 Dual Distribution Amplifier Teardown, Repair & Experiments
17.9K views
November 12, 2023 10:52 PM
In this episode Shahriar repairs a fault SRS FS735 dual distribution amplifier. These instruments provide two independent 7-channel 10MHz distribution modules with exceptional signal purity and isolation. The instrument does not properly powers on which points to a potential problem with the internal power supply.
The unit has two identical power supplies; one for each module. Both power supplies have a failed startup capacitor which can be easily replaced. After the repair, the power supplies are verified for functionality and power delivery. The schematic of the entire unit is described as well as a view of the module PCB. The performance of the unit across frequency, harmonic distortion as well as isolation behavior is also measured and verified.
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TSP #234 - QuantAsylum QA403 24-bit, 0.0001% THD Audio Analyzer Review, Teardown & Experiments
37.3K views
October 29, 2023 9:16 AM
In this episode Shahriar takes a detailed look at the QuantAsylum QA403 24-bit, extraordinary linear & low-noise audio analyzer. This low-cost instrument provides the means to test a wide range devices in the audio frequency range:
https://quantasylum.com/collections/frontpage/products/qa403-audio-analyzer
The review of the instrument is organized as follows:
00:00 – Introduction, instrument interfaces and overview
01:03 – Detailed teardown, architecture overview, ADC, DAC, amplifiers, attenuators and interface challenges; isolated properties, THD and SNR considerations
10:14 – Instrument extreme performance verification through loop-back; detailed GUI overview, ADC & DAC operations, attenuators, THD measurements, built-in generators and measurement functions
22:47 – Stanford Research Systems (SRS) DS360 Ultra Low Distortion Generator performance verification using the QA403
25:28 – Characterization of the SRS SR560 Low-Noise Preamplifier, linearity, THD+N, low-pass and high-pass filters responses, low-noise versus dynamic reserve measurements, automated sweeps
35:40 – Characterization of a two-stage audio amplifier and headphone driver module; gain and THD variation measurements as a function of frequency
38:55 – QuantAsylum family of products, example measurements and additional resources
39:27 – Concluding remarks
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