TSP #143 - Teardown & Repair of an Agilent N9020A MXA 10Hz - 8.4GHz Spectrum Analyzer (Jan. 19 - P2)
25.1K views
January 26, 2019 4:36 PM
In this episode Shahriar repairs an Agilent N9020A MAX Spectrum Analyzer. The instrument is well equipped with real-time capability and direct I/Q input ports on the front panel. The instrument does not show the correct signal levels and fails internal calibration.
After a brief teardown, the block diagram of the instrument is carefully examined for potential failure points. It is determined that front-end switch and mechanical attenuator is likely faulty. Teardown of the unit reveals significant damage to the attenuator due to some high-power at the input. Unfortunately, this also implies that the front-end RF selector and pre-amplifier modules are also damaged. In the second repair video, the front-end module is disassembled and damage to the dies can be observed.
Luckily, a relatively inexpensive front-end (SSLAM) unit is sourced from eBay and the repair is completed. The performance of the unit is verified after the repair and the front-end I/Q input functionality is demonstrated.
The Signal Path
http://www.TheSignalPath.com
http://www.YouTube.com/TheSignalPath
http://www.Patreon.com/TheSignalPath
TSP #142 - Teardown & Repair of an Agilent N9020A MXA 10Hz - 8.4GHz Spectrum Analyzer (Jan. 19 - P1)
20.4K views
January 6, 2019 11:40 PM
In this episode Shahriar repairs an Agilent N9020A MAX Spectrum Analyzer. The instrument is well equipped with real-time capability and direct I/Q input ports on the front panel. The instrument does not show the correct signal levels and fails internal calibration.
After a brief teardown, the block diagram of the instrument is carefully examined for potential failure points. It is determined that front-end switch and mechanical attenuator is likely faulty. Teardown of the unit reveals significant damage to the attenuator due to some high-power at the input. Unfortunately, this also implies that the front-end RF selector and pre-amplifier modules are also damaged. In the second repair video, the front-end module is disassembled and damage to the dies can be observed.
Luckily, a relatively inexpensive front-end (SSLAM) unit is sourced from eBay and the repair is completed. The performance of the unit is verified after the repair and the front-end I/Q input functionality is demonstrated.
The Signal Path
http://www.TheSignalPath.com
http://www.YouTube.com/TheSignalPath
http://www.Patreon.com/TheSignalPath
TSP #141 - Texas Instrument TI-PMLK Power Management/Conversion Kit Tutorial, Review & Experiments
20.9K views
December 31, 2018 1:38 AM
In this episode Shahriar presents a meticulously prepared set of educational lab kits on Power Conversion by Texas Instruments. These kits include Buck, Boost, LDO and Buck-Boost power conversion courses complete with a beautiful set of lab instructions and PCBs. Each kit describes up to 7 different exercises which demonstrates various aspects of power conversion characterization and design challenge.
In particular the Buck Lab kit is examined. The PCB is populated with two different Buck DC-DC converters which are carefully described in the lab kit. The first experiment of the lab kit is performed which involves measuring system efficiency under various load conditions and switching frequency. The inductor current, MOSFET switching voltage and output waveform are examined on the oscilloscope.
You can find information about these lab kits at:
http://ow.ly/Q7LF30nc8Bd
The Signal Path
http://www.TheSignalPath.com
http://www.YouTube.com/TheSignalPath
http://www.Patreon.com/TheSignalPath
TSP #140 - How Do Purely Passive Watt-Meters Work? (Giveaway Results & More Giveaway! December 2018)
17.4K views
December 16, 2018 12:56 AM
In this episode Shahriar demonstrates the principle of operation of a purely passive Weston watt-meter manufactured in the 1950’s in Newark, NJ, USA. This watt-meter makes no use of active devices (tube or solid-state) and yet is able to measure real-power both at DC and AC.
The teardown of the unit shows the construction of two coils interacting to advance the needle on the display. One coil produces a magnetic flux proportional to the current input and the other coil produces a magnetic flux propositional to the voltage. The interaction of the flux moves the needle proportional to the total power which is the product of current and voltage. The instrument is then used in conjunction with a power supply and electronic DC load to verify its functionality.
The Signal Path
http://www.TheSignalPath.com
http://www.YouTube.com/TheSignalPath
http://www.Patreon.com/TheSignalPath
TSP #139 - Teardown & Repair of an GW Instek PSW80-40.5 1080W Multi-Range Programmable Power Supply
27.5K views
November 23, 2018 4:19 AM
In this episode Shahriar investigates the failure of a GW Instek 1080W power supply capable of providing up to 80V and 40A of programmable output voltage and current respectively. The power supply does not power on. However, relay noises can be heard inside the instrument during power on.
Teardown of the unit reveals a modular design with PCBs on all sides. The instrument comprises 6 different modules and 3 complete power supplies in parallel. The controller circuit is powered from the middle power supply module. Examination of the boards reveals three separate failed devices. The in-rush power resistor which prevents the main supply board from startup, a damaged MOS power transistor on the supply output and surface mount resistors. All components are replaced. The instrument’s performance is verified with a BK Precision 8601 electronic load.
The Signal Path
http://www.TheSignalPath.com
http://www.YouTube.com/TheSignalPath
http://www.Patreon.com/TheSignalPath
