TSP #71 - Teardown, Repair & Calibration of a Valhalla 2701C Precision DC Voltage Standard
25.7K views
January 12, 2016 12:59 AM
In this episode Shahriar examines a faulty Valhalla 2701C Programmable Precision DC Reference instrument. Valhalla Scientific’s 2701C Programmable Precision DC Voltage Calibrator delivers ultra-precision, ultra-stable DC voltage from 100 nanovolts to 1200 volts. This unit does not have a working front-panel LCD screen. Luckily, that problem is resolved very quickly.
The internal build and operation of the unit is briefly examined and the instrument is calibrated using a Keithley DMM7510 7.5-digit multimeter. It is possible to upgrade this unit to a more stable and accurate reference voltage generator or to add the reference current capability to it.
The Signal Path Blog
http://www.TheSignalPath.com
TSP #70 - FLIR MR160 Thermal Imaging & Moisture Meter Review, Teardown & Experiments
32.8K views
January 10, 2016 1:56 AM
In this episode Shahriar takes a close look at the FLIR MR160 Thermal Imaging and Moisture Meter. Featuring Infrared Guided Measurement (IGM) technology powered by a FLIR Lepton® thermal imaging sensor, MR160 helps you quickly see temperature patterns that point to potential hidden moisture so you know right where to place the meter probe to capture accurate readings.
After an overview of the camera functions a full teardown of the instrument is presented. The FLIR MR160 is based on a single PIC32 processor with built-in capacitance measurement capability. The MR160 is then used to detect a moisture spot on a floor tiling. The presence of moisture is then verified with both the pin-less and pin-based moisture measurement capability of the MR160. Finally, the MR160 is also used to measure temperature variation across a bank of resistors.
The Signal Path
http://www.TheSignalPath.com
TSP #69 - Keysight EXA Signal Analyzer / Spectrum Analyzer Review, Teardown & Experiments
29.8K views
December 25, 2015 9:48 PM
In this episode Shahriar reviews the Keysight EXA Signal Analyzer / Spectrum Analyzer (N9010A). The X-Series Signal Analyzers and Spectrum analyzers from Keysight are compared against each other. The EXA is a general purpose spectrum analyzer with extensive applications.
The full instrument block diagram is presented with focus on various signal paths and frequency planning. Several of internal modules (RF Front-End, Digital Baseband Processor and LO Synthesizer) are also presented and compared with the block diagram. In order to examine the instrument’s capabilities in a real-world situation, a complete superheterodyne wireless transceiver with a sliding-IF receiver is design and examined. Each individual component in the system (LNA, mixer, PLL, etc.) are individually characterized by using the EXA Signal Analyzer. The complete system measurements are also presented.
Various chapters in the video can be found at the following time marks:
Introduction (0:08)
Model comparison (0:50)
Instrument block diagram (4:27)
Module teardown and examination (20:39)
Instrument front/back panel (37:05)
Measurement setup description (43:22)
Doubler characterization with EXG as tracking generator (45:31)
LNA and mixer with Noise Figure personality and gain (57:31)
Signal Hound VSG25A I/Q modulator with OBW, ACPR, TOI (1:08:57)
PLL characterization with Phase Noise personality (1:19:49)
Full transmitter measurement with Keysight VSA (1:26:08)
Full wireless link characterization (1:30:28)
Concluding remarks (1:37:21)
The Signal Path
http://www.TheSignalPath.com
TSP #68 - Tutorial on the Theory, Design and Characterization of a CMOS Transimpedance Amplifier
28.9K views
December 13, 2015 1:30 AM
In this episode, Shahriar and Shayan discuss the design and characterization of a deceptively simple CMOS inverter-based transimpedance amplifier. The the large and small signal behavior of the CMOS inverter is discussed and measured using the Keithley 2450 and 2460 source meters. The transient response is also measured using a Keysight MSO-S series oscilloscope.
The small signal gain of the circuit is calculated from small signal parameters which are extracted directly by measuring the devices I/V characteristics. The NMOS/PMOS devices used are from an ADL1105 quad-discrete transistor IC. Through the use of a shunt-shunt feedback, the CMOS amplifiers is converted to a transimpedance amplifier which is capable of amplifying the current from a photo-detector diode by a gain of 30kV/A. The feedback theory is used to calculate the gain of the amplifier. The slides for this tutorial can be downloaded from The Signal Path website.
The Signal Path
http://www.TheSignalPath.com
TSP #67 - Tutorial and Experiments with ESP8266 SoC, Arduino and Internet of Things (IoT)
40.6K views
December 7, 2015 1:43 AM
In this episode Shahriar explores the functionality of the popular ESP8266 SoC chip. This IC incorporates a full ISM radio as well as the physical/MAC layer for 802.11b/g/n network communication. Furthermore it includes a uC core for code execution making it a low-cost candidate for Internet of Thing applications. This video uses a Sparkfun Thing evaluation board which also includes a LiPo batter charger, voltage regular, flash memory and all the I/O pins which are accessible to the user. The block diagram of the ESP8266 is reviewed as well as the schematic of the complete Sparkfun Thing board.
By using an Arduino library and the iOS application, a cell phone and the ESP8266 can simultaneously communicate with a server running the IoT application and transfer data between the application and the module. In this demo various components such as NeoPixel (WS2812), OneWire temperature sensor and battery monitoring functionality are implemented. The code is available from The Signal Path website.
The Signal Path
http://www.TheSignalPath.com
