TSP #16 - Teardown and Repair of an HP 8648C Synthesized Signal Generator
58K views
October 7, 2012 12:44 AM
In this episode Shahriar attempts to repair an HP 8648C Synthesized Signal Generator from a dumpster dive. The cause of failure is investigated and traced. Alongside the repair efforts, the internal construction and components of the synthesizer are also presented. Various component teardowns are shown and described including the structure of the VCO used in the generator assembly. The functionality of the repaired unit is verified using an Agilent Power Meter and Rigol Spectrum Analyzer. Finally, the overall unit block diagram is presented and the principle of operation is described in detail.
The Signal Path
http://www.TheSignalPath.com
TSP #15 - Tutorial on the Theory, Design and Characterization of a Single Transistor BJT Amplifier
185.9K views
September 22, 2012 10:55 PM
In this episode Shahriar presents a tutorial on the design and characterization of a single-stage low-noise bipolar amplifier suitable for audio applications. Given a set of specifications, a common-emitter topology is investigated. The circuit employs a beta-insensitive biasing scheme which is simultaneously optimized for maximum output swing. The small-signal gain of the circuit is calculated and the bandwidth is set for audio frequencies. A non-inverting operational amplifier is used as a second stage to achieve the desired overall gain. The circuit is assembled on a breadboard where the gain and bandwidth are measured and compared with design specifications. As the final experiment, the circuit is used to amplify signals from a microphone.
The Signal Path
http://www.TheSignalPath.com
TSP #14 - Cryogenic Experiments on Passive and Active Electronic Components
19.3K views
July 21, 2012 10:13 PM
In this episode, Shahriar investigates the theory and experimental results of the impact of extreme low temperatures on passive and active components. Liquid Nitrogen in used in a transparent glass Dewar where different components can be fully submerged in the liquid. Various types of resistors are compared for their temperature stability. An electromagnet which uses Copper coils is used to generate a magnetic field at a constant power consumption at both extreme temperatures. The impact of liquid nitrogen on the junction voltage of an NPN device is measured as well as the frequency shift of a CMOS ring oscillator. Finally, the wavelength shift of an LED submerged in liquid nitrogen is studied. There is a puzzle at the end of this video, please share your thoughts in the comments section.
The Signal Path
http://www.TheSignalPath.com
TSP #13 - Teardown and Operation of an Advantest TQ8325 Wavelength Meter
10.4K views
July 15, 2012 9:06 PM
In this episode Shahriar presents the teardown of an Advantest TQ8325 Wavelength Meter. The principle operation of the instrument is explained along with a close up of the free space optics in operation. To verify the functionality of the unit, an infrared laser module is used as a CW coherent source. The impact of the laser diode’s temperature variation on the output wavelength is measured using the wavelength meter.
The Signal Path
http://www.TheSignalPath.com
TSP #12 - Rigol DM3068 6.5 Digit Digital Multimeter Review
82.7K views
July 2, 2012 10:34 AM
In this episode, Shahriar reviews the Rigol DM3068 6.5 Digit Digital Multimeter. The Model DM3068 DMM gives reliable, cost effective, full DMM capabilities measuring DCV, ACV, DCI, ACI, Resistance (2 & 4 Wire), Capacitance, Diode Test, Frequency, and Temperature. These DMMs are designed for simple and efficient bench top use, but include software options for datalogging and remote programming from almost any interface.
Shahriar demonstrates various functionality including a computer guided destructive LED IV tracer to investigate LED failure patterns. The DM3068 can be purchased for $799 US dollars from Rigol Inc. The DM3058 offers similar functionality at 5.5 Digits for $695 US dollars.
The Signal Path
http://www.TheSignalPath.com
