In this episode Shahriar attempts to repair a Fluke Documenting Process Calibrator. The device does not power on with neither a battery nor an external power supply. Although the schematic of this particular instrument is not available, an older model schematic shares many of the design aspects. After close examination of the circuit and various testing of power supply sub-circuit, real-time clock and main processor, it becomes clear that the problem is with a corrupt firmware. The repair is put on hold until a firmware upload method is determined.
After some help from the community, a new firmware has been found and can be uploaded into the instrument. By forcing the processor into a bootloader mode, the firmware update can happen even if the original firmware is corrupted. After the firmware fix, the instrument is tested for various functionality include DC/AC/I/Resistance calibration and measurement modes.
In this episode Shahriar reviews the top-of-the-line Tektronix 6-Series Oscilloscope. This 4-channel instrument offers 8-GHz of bandwidth at 25GS/s on all channel independently. Tektronix has made great strides in offering low-noise front-end custom ASICs combined with hardware digital down-conversion built into the core of the 6-Series. This enables advanced triggering across in both time and frequency domains as well as multi-domain correlated measurements.
This review is organized as follows:
00:06 – Introductions
01:42 – Instrument design, front and back panels
03:34 – Full acquisition board teardown, analysis and architecture
18:11 – PLL Experiment: Spectrum View, advanced triggering, PLL characterization and debugging
38:33 – Backplane Communication: Jitter analysis, eye diagrams, jitter composition, cross-talk
49:24 – Concluding remarks
In this episode Shahriar reviews the long awaited Signal HoundSM200C/B Real-Time 100kHz – 20GHz Real-Time Spectrum Analyzer:
The SM200C is a high-performance spectrum analyzer and monitoring receiver with a 10 Gigabit Ethernet SFP+ port, enabling the SM200C to communicate with a PC over long distances using a fiber optic cable. Designed for remotely-located accurate RF data analysis at the lowest cost possible, the SM200C features:
160 MHz instantaneous bandwidth I/Q streaming over 10GbE
SFP+ port for fast, long-distance communication with a PC using an optic cable
Device control and data transfer occurs via SFP+ connection, not USB
Tunes from 100 kHz to 20 GHz
Sweeps at 1 THz/sec at 30 kHz RBW
110 dB of dynamic range
Ultra-low phase noise
GPIO port antenna switching
The SM200B offers a USB 3.0 PC interface with 40MHz of instantaneous I/Q streaming. Furthermore, the SM200B includes a full 2-second of internal memory at 160MHz of capture bandwidth which an be accessed through the API.
The review is organized as follows:
00:00 – Introduction
00:49 – Overview, build quality and detailed specifications
05:51 – Full teardown, analysis and system architecture
18:00 – 10GbE PC interface using M.2 Key to PCIe converter
19:22 – Experiment #1: FMCW signal analysis, GUI overview & 160MHz capture capabilities
31:33 – Experiment #2: Interfering hunting, FM-versus-time, frequency hopping & advanced triggering
41:32 – Experiment #3: Digital demodulation, phase-noise & equalization
46:02 – Other GUI capabilities, mask & EM compliance, API
47:20 – Concluding remarks
In this episode Shahriar retrofits a vintage HP 8445B Auto Preselector for testing and characterization of high-performance data converters and oscilloscopes. The Preselector is in essence an electronically tunable band-pass filter with exceptional tuning range and quality factor.
After examining the schematic and block diagram of the instrument the unit is equipped with additional potentiometer, low-band, high-band switch and a voltmeter LCD screen which displays the center frequency. The modifications are applied to the front panel as well as internal circuitry to enable manual control of the preselector without the need for any external devices.
The modified instrument is used to measure the harmonic improvement of a 20GHz synthesizer. Several oscilloscopes are then characterized using the new preselector to determine the absolute performance of their internal data converter.
Finally, it is also time for a new giveaway! A brand new Keysight DSOX1102G scope! Patreon supporters are automatically enrolled.
In this episode Shahriar takes a look at a R&S SMBV100A Vector Signal Generator which does not produce the correct output level. Despite passing all self-tests and ALC checks, the output power level is far below expectation. The output also shows a high-pass frequency response.
The (heavily simplified) block diagram of the instrument is examined and discussed. The teardown of the unit reveals the output RF board which is presented in details. Since the instrument cannot detect the failure internally, it is very likely that the fault is part of the RPP output RF relay. The circuitry as well as the datasheet of the components are examined. Measurements show that the output RF relay is never activated due to a faulty PMOS transistor. After transistor is replaced, the unit shows the correct output level. The baseband generator functionality is also verified.
The Signal Path (TSP) is an electrical engineering video blog for industry professionals, students and hobbyists. TSP is a non-for-profit website dedicated to provide free education spanning a wide range of electrical engineering topics. Equipment reviews, tutorials and repair videos are posted regularly.