In this episode Shahriar reviews the affordable ERASynth Micro 12.5MHz – 6.4GHz portable synthesizer with a built-in LCD screen. The USB powered instrument is fully open-source, Arduino compatible and can be operated in stand-alone mode. The system block diagram and operation of the instrument is presented.
The measurements show some of the strengths and limitations of the instrument in AM/FM modulation modes and general CW use cases.
In this episode Shahriar does a deep dive into the operation and architecture of Agilent/HP mm-Wave Extension Modules and Controller. The Agilent 85015A and W85104A work in conjunction and as the front-end for a W-Band (75-110GHz) S-Parameter T/R set. Although the mainframe system (HP 8510 Network Analyzer) is not available, a close look at the block diagrams reveals that the controller can be driven via external synthesizers to provide LO and RF signals. The detailed explanation of the entire system is presented from the ground up.
The full teardown of the mm-wave controller and T/R module are also presented and by reverse engineering the GPIB commands, the T/R module is brought to life. Several experiments show the full functionality of the system including a high-resolution CW radar demonstration.
In this episode Shahriar repairs a non-functional N4901B 13.5Gb/s BERT mainframe. This instrument is equipped with both the generator and analyzer modules which makes it fairly valuable. The instrument does not power on and does not react to the soft power button.
Teardown of the unit reveals a TD-Lambda Vega power supplies series which is a fully configurable switching power supply design. Even though the power supply in the instrument is completely custom, it is made from generic sub-blocks readily available on eBay. A replacement front-end is purchased to repair the power supply after detecting the problem.
The instrument also shows a minor problem with falsely detecting an overload condition on the delay control port which is by passed by installing an overwrite switch. The instrument performance is verified by generating and measuring various eye diagrams through a back-plane PCB board.
In this episode Shahriar continues his review of the Tektronix 5-Series 8-Channel MSO Oscilloscope following the original overview of the instrument. A full teardown of the instrument as well as a set of experiments showcasing the new Spectrum View capability are shown. This review is organized as follows:
00:09 – Introduction and outline
01:31 – Teardown and analysis of the acquisition board
13:38 – Experiment setup and description
16:59 – Measurement results and Spectrum View capabilities
33:12 – Concluding remarks
In this episode Shahriar takes a close look at an EG&G DSP-Based Lock-In Amplifier. This instrument provides excellent sensitivity for both voltage and current inputs and is based on a fully digital architecture. The instrument’s LCD screen is dim and unreadable. Furthermore, a few lines are missing from the LCD pointing to a failed zebra strip.
The instrument’s block diagram is examined and explained. The teardown reveals the structure of the LCD screen, front-end blocks and internal PLL. The CCFL back-light inverter is located and replaced with a low-voltage DC-DC converter for use with an LED strip. The instrument’s functionality is verified through a few experiments including measuring the 3dB bandwidth of an RC filter as well as measuring the photo-current induced in an LED using a synchronized infrared light source.
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.