TSP #244 - Agilent 3458A 8.5-Digit Multimeter Repair, Teardown & IC Analysis (April 2024)
In this episode Shahriar repairs a faulty Agilent 3458A. These highly desirable multimeters have continued to climb in price in the past few years. The last time The Signal Path has repaired one of these units was back in 2018.
This instrument generates several errors both during power up as well as Auto Cal procedure. The error points to a failure in the OHMS measurement mode. Detailed instrument block diagram and schematics are examined. Measurements also show incorrect DC current sourcing during OHMS measurements and the associated circuits are closely analyzed. The problem is traced to a quad-comparator IC. Replacement corrects all problems during ACAL. The battery backup of the SRAM ICs are also replaced to eliminate non-volatile errors. The IC of the comparator chip is also extracted and examined under the microscope.
The repaired instrument performance is verified by using voltage, current and resistance standards.
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TSP #243 - Agilent FieldFox N9912A 4GHz Handheld RF Analyzer Repair & Teardown
In this episode Shahriar repairs an Agilent N9912A which flags several error messages after bootup. The instrument reports hardware time-outs and occasionally ADC clock source unlock condition. The second error is much more useful in debugging the unit.
The block diagram of the instrument is presented and several potential failures anticipated.
The teardown of the unit and analysis is also presented. After some troubleshooting, it becomes clear that the primary 30MHz TCXO has a broken internal connection. The unit is disassembled and new pins installed. After putting the TCXO back into the unit, the instrument return to full functionality. A few quick experiments verify that the FieldFox performs both CAT and SA modes correctly.
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TSP #242 - Sanko GH60 6GHz Handheld Vector Signal Generator Review, Teardown & Experiments
In this episode Shahriar shows an extensive review of the Sanko (BirdRF) GH60 GeneHawk handheld vector signal generator which operates from 10MHz – 6GHz. With up to 100MHz of modulation bandwidth (licensed) the unit has good potential for a portable wide-band communication signal generator:
https://www.sankorf.com/products/portable-signal-generator-gh60
This review is organized as follows:
00:00 – Introductions, unit overview, operating system & GUI initial impressions
02:33 – Detailed teardown, construction, RF & baseband board analysis
19:16 – Frequency accuracy and stability measurements
20:31 – Output power measurement, power linearity and minimum output power
24:28 – CW signal analysis, noise-floor, harmonic behavior and spurious tones
27:15 – Phase noise characterization, spurs and far-out noise floor
28:41 – Two-tone generator, TOI (OIP3), image rejection, LO rejection, intermodulation tones
31:13 – Pulse generation, minimum pulse behavior
33:36 – Linear frequency generation measurements & characteristics
34:58 – FM, AM & PM capabilities and characterization methods, multi-modulation options
37:22 – Frequency sweep behavior and limitations
40:07 – Custom digital modulation, EVM measurements, I/Q & magnitude error, equalization
43:05 – Real-time AWGN performance and measurements
44:00 – Other software features, up-coming API and waveform standards
44:44 – Concluding remarks
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TSP #241 - Ametek Jofra CTC-140A (-17C TO +140C) Dry Block Calibrator Repair & Teardown
In this episode Shahriar takes a look at a faulty dry block calibrator from Ametek. These Jofra series temperature calibrators are widely used for thermostat validation as well as material analysis. This particular unit does not cool down or warm up but seems otherwise functional.
A brief set of measurements shows that one of the Peltier elements is damaged and should be replaced. A replacement is located and the temperature well is re-sealed. The unit is functional and the minimum temperature performance is verified.
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TSP #240 - Rohde & Schwarz 70GHz, 75dB Electromechanical Step Attenuator Teardown & Failure Analysis
In this episode Shahriar takes a look at a very high-end step attenuator designed by Rohde & Schwarz for their FSU family spectrum analyzers which cover over 67GHz of sweep frequency.
The attenuator teardown and architecture is thoroughly presented with focus on how the high-frequency performance is maintained in a moving environment. Furthermore, the individual attenuator pads are examined under the microscope for their construction and design where the 5dB pad failure can also be observed.
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TNP #47 - SHF 100CP 20GHz Broadband GaAs FET Amplifier Teardown & Experiments
In this episode Shahriar takes a close look at a 20GHz GaAs amplifier module intended for 40Gb/s optical applications. Despite being marked as "broken", initial measurements show the amplifier to be functional A teardown of the module is presented alongside detailed performance verifications and measurements.
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TSP #239 - SJL Instruments 6GHz GigaWave Sampling Oscilloscope Review, Teardown & Experiments
In this episode Shahriar review the new sampling oscilloscope from SJL Instruments. Our GigaWave™ digital sampling oscilloscopes offer 12-bit vertical resolution, 1-ps time resolution, and 6 GHz analog bandwidth, all in a tiny 4” form factor:
https://www.sjl-instruments.com/
You can also find an on-going discussion about the instrument here:
https://www.eevblog.com/forum/testgear/pocket-sized-6-ghz-1-tss-et-scope
This review is organized as follows:
00:00 - Introductions
00:34 - Sampling scope & real-time scope theory and comparison
04:13 - CDF versus PDF method of waveform reconstruction
06:12 - Teardown & circuit analysis
09:35 - Input return loss characteristics and channel isolation
10:36 - GUI overview, capturing a fast pulse, comparison with Keysight DCA-X, built-in measurements, dot and vector mode
19:09 - Eye diagram measurements, ISI measurements, multi-channel view
24:15 - Multi-tone capture, FFT functions
25:09 - Concluding remarks
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TSP #238 - Rohde & Schwarz FE170SR D-Band (110 - 170GHz) Sub-THz Frontend Overview & Experiments
In this episode Shahriar takes a close look at the Rohde & Schwarz FE170SR which is the world's first fully abstracted D-Band front-end module. Intended for early sub-terahertz 6G research, the fully integrated module is capable of seamlessly interfacing with both spectrum analyzers and oscilloscopes - only a 10MHz reference is needed!
https://www.rohde-schwarz.com/us/products/test-and-measurement/frontends-and-converter/rs-fe170sr-frontend_334208.html
The video goes over the history and evolution of external mixers and front-ends to better capture the uniqueness of the FE170SR. The internal block diagram and theory of operation of the instrument is also presented. Experiments show detailed measurement techniques using the FE170SR and the RTP oscilloscope. The integration of the FE170SR with R&S VSE is also presented through demodulation of broadband QAM signals at a carrier of 145GHz.
Furthermore, the newly released R&S Thermal Power Sensor at D-Band is also shown in the video:
https://www.rohde-schwarz.com/us/products/test-and-measurement/rf-and-microwave-power-sensors/rs-nrpxxt-tn-twg-thermal-power-sensors_63493-197529.html
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TNP #46 - Torbal AD60 Precision Balance (0.001g) Repair, Teardown & Experiments
In this episode Shahriar takes a look at a Torbal precision scale capable of resolving 0.001g! Unfortunately the unit shows an error of "Unload" when powered on. The teardown of the unit as well as the principle operation is described. The teardown also reveals the problem with the scale mechanism which is a broken link. The repair correct the problem and the scale shows excellent accuracy with calibrated weights. The live evaporation of Acetone is also shown using the precision balance.
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TNP #45 - Tektronix TekVPI TPA-BNC (TekProbe Converter) Adapter Repair & Teardown
In this episode Shahriar upgrades the internal firmware of a TPA-BNC TekVPI adapter. The teardown of the adapter is presented and the internal architecture described. The firmware is copied from a newer unit to the faulty one and the adapter can now detect a wide range of probes.
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TSP #237 - Rohde & Schwarz LCX200 Precision 10MHz LCR Meter Review, Tutorial, Teardown & Experiments
In this episode Shahriar presents a detailed review of the Rohde & Schwarz LCX200 LCR meter. The new LCR platform from Rohde & Schwarz can operate up to 10MHz with a basic accuracy of ±0.05% for impedance measurements:
https://www.rohde-schwarz.com/us/products/test-and-measurement/lcr-meters-and-impedance-analyzers/rs-lcx-lcr-meter_63493-1172288.html
With capabilities such as binning, logging and sweeps, there is a lot to talk about! This review is organized as follows:
00:00 – Introductions
00:46 – Instrument overview, front & back panels
02:57 – Test fixtures and fixture teardown
04:28 – Detailed teardown, architecture, sub-component overview
11:23 – Remote interface, GUI overview, measurement parameters, fixture compensation
15:14 – Capacitor standard measurement, parameters setup, incident voltage, LowZ mode, auto-ranging
19:43 – Capacitor impairment measurements, Cs/Rs/Cp/Rp comparison, DC resistance & leakage measurements
21:44 – In-circuit measurements considerations, active device impacts
22:49 – Variable capacitor measurements, logging & plotting performance
25:37 – LC resonance measurements, frequency sweep capabilities, SRF detection, data export & post processing
29:22 – PN junction varactor measurements, DC bias sweep, active device characterization
31:35 – Variable inductor measurements, current stimulus capabilities, quality factor measurements
32:59 – Transformer fixture & transformer characterization, number of turns, mutual inductance and transformer verifications
35:02 – Surface mount device measurements, setup for binning and statistical measurements, triggering
37:05 – External DC bias voltage setup, internal voltage readout, 40V capability
38:57 – Concluding remarks & future improvements
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TNP #44 - AT&T 938A LED Optical Loss Set Repair, Teardown & Experiments
In this episode Shahriar takes a look an AT&T optical loss set which is equipped LED sources 875nm & 1300nm. The unit has been storage for over a decade with heavily leaked batteries.
After the cleanup, the unit powers on and is able to measure optical power as well as generate light from the LED source. The accuracy of the photodetector is verified against a calibrated optical meter. The wavelength of the 875nm LED source is also measured using a spectrometer.
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