Archive for the ‘Electronics’ Category.

HP 8620C Sweep Generator Repaired

In my previous post, I did a teardown of an HP 8620C sweep generator along with an HP 86245A 5.9 GHz to 12.4 GHz RF plugin. A few of the plguin boards in the 8620C had leaked capacitors and also there seemed to be some sort of mechanical issue as no power was delivered to the transformer regardless of the power switch positions. So what I planed to do next was to restore the power to the unit and replace those bad capacitors and see if I could bring this sweep generator back to life. Continue reading ‘HP 8620C Sweep Generator Repaired’ »

Capacitor Plague? Inside an HP 8620C Sweep Oscillator and HP 86245A RF Plugin

I just picked up an HP 8620C sweep oscillator with an HP 86245A 5.9 GHz to 12.4 GHz RF plugin on eBay. This time around though, the unit does not work. While it was advertised as a working unit I could not get it powered on and there was no sign of life whatsoever. So before I start troubleshooting and repairing the unit, I thought I would do a quick teardown to see what’s inside and if I could spot anything obvious that was out of the ordinary. Continue reading ‘Capacitor Plague? Inside an HP 8620C Sweep Oscillator and HP 86245A RF Plugin’ »

Teardown of an HP 8671A Microwave Frequency Synthesizer

I recently bought an HP 8671A microwave frequency synthesizer on eBay. This synthesizer can generate signals from 2GHz to 6.2GHz with an unleveled output of more than 8dBm. It is a nice complement to my HP 8642B signal generator and Wavetek 907 signal generator. Using these generators, I can now generate signals of pretty much any frequencies under the 12GHz range. A video of this teardown is linked towards the end of this post. Continue reading ‘Teardown of an HP 8671A Microwave Frequency Synthesizer’ »

Further Disassembly of the HP 493A TWT

My video on the teardown of an HP 493A traveling wave tube amplifier had generated quite a bit of interest. After I revealed that the electron gun portion of the tube was radioactive, a couple of my YouTube channel viewers had wondered if I could take the traveling wave tube further apart. So I did just that. Continue reading ‘Further Disassembly of the HP 493A TWT’ »

Featured on EEVBlog – HP493A Teardown

Big thanks to Dave Jones at the EEVBlog for featuring one of my teardown videos. His generosity would certainly help smaller channels like mine attracting more viewers. Continue reading ‘Featured on EEVBlog – HP493A Teardown’ »

Amrel PPS-2322 Programmable Power Supply Firmware Backup

Quite a few people had contacted me on the availability of the firmware for the Amrel PPS-2322 programmable power supply I did a teardown with a few years ago. I finally got a chance to it and backed it up with my TL866A, better late than never. For those who wanted to download a copy of the firmware, you can find the link towards the end of this post. Continue reading ‘Amrel PPS-2322 Programmable Power Supply Firmware Backup’ »

Inside a PM1A Color Analyzer

As I mentioned in one of my posts a few years back, a color analyzer from the 80’s can be a treasure trove for the hobbyists. And at the very least, it is a cheap way to get yourself a photomultiplier along with the supporting circuitry to do experiments with. For instance, you can utilize the fast response time of a PMT to do accurate speed of light measurement in a lab setting like I showed in this experiment back in 2015. Continue reading ‘Inside a PM1A Color Analyzer’ »

Teardown of a 65W Cree LED Bulb

I few months back, I wrote about my experience with the six dimmable Philips LED bulbs I purchased a year ago. Those light bulbs all failed within months of each other in just over a year of use. This time around though, it’s the Crees ones that had bit the dust. They lasted a few months longer and were among the twelve I originally purchased. So I decided to open up one to see how the Cree LED bulbs were constructed. Continue reading ‘Teardown of a 65W Cree LED Bulb’ »

Teardown of an Extech 380460 Milliohm Meter

In this blog post, let’s take a look at what’s inside an Extech 380460 miliohm meter. Continue reading ‘Teardown of an Extech 380460 Milliohm Meter’ »

Reverse Engineering of BK Precision 1696 Switching Power Supply’s LCD Protocol

As mentioned in my previous post, besides the broken LCD there was also an issue with the power supply portion of the unit and the output voltage was clamped at around 10 to 11V. The digital circuitry portion however seemed to be intact. Unfortunately since an identical LCD is virtually unobtanium, I thought I’d reverse engineer the LCD protocol so once the power supply is fixed I can fix the display by hooking up a different LCD. Continue reading ‘Reverse Engineering of BK Precision 1696 Switching Power Supply’s LCD Protocol’ »

Teardown of a BK Precision 1696 Programmable Switching Power Supply

I recently picked up a BK Precision 1696 programmable switching power supply off eBay. Unlike many of the vintage test equipment I did teardowns with in the past, this model is still in production today. The one I got was sold with a damaged LCD screen and thus I paid very little for it. Of course, a brand new one would cost around $300. Continue reading ‘Teardown of a BK Precision 1696 Programmable Switching Power Supply’ »

Teardown of a Watts Up? Pro ES Power Meter

Power meters for measuring power consumption of consumer electronics have been around for at least a decade. The most popular ones are argubly P3 International‘s power meters and many of its clones. I have a later version of the P4400 which was based on a COB design. Some earlier manufactured P4400’s used off-the-shelf ICs. The Watts Up? power meters were first seen roughly around the same time as P3’s Kill A Watt meters. However, they never became as ubiquitous as the Kill A Watt due to their high prices. But compared to Kill A Watt power meters, Watts Up? meters do seem to offer better functionalities. The Pro series for example are equipped with USB interfaces and thus allow easy data logging and data analysis on computers. Continue reading ‘Teardown of a Watts Up? Pro ES Power Meter’ »

Diode Equation and Forward Current Measurement

We are all familiar with the I/V characteristics of a diode. The main characteristics of a typical diode is that when forward biased, it starts to conduct as the voltage applied approaches the threshold voltage of the diode and the current increases exponentially as the forward voltage increases. This behavior can be modeled by the Shockley diode equation. A question frequently asked is that what happens when the applied forward voltage is very small, say just a few millivolts? Continue reading ‘Diode Equation and Forward Current Measurement’ »

Modifying a Computer ATX Power Supply For Higher Output Voltage

To charge the 110Ah battery bank I built, I need a power supply that can provide at least 10A at 14.6V. Since I have many old ATX power supplies lying around and the 12V rails of these power supplies are more than capable of providing 10A, I decided to modify one such power supply for using as a 4S LiFePO4 battery charger. Continue reading ‘Modifying a Computer ATX Power Supply For Higher Output Voltage’ »

Teardown and Testing of an 800W PureSine Inverter

The last ingredient for my backup power project is an inverter. Since the battery bank I built is a 12V 1.5kWh one, an inverter that can handle a load between 500W and 1000W would be a suitable choice. In theory, all the lights and the refrigerator in my house consume just around 500W. So the 1.5kWh battery bank should be able to power all the essentials for at least a couple of hours in the event of a power failure. Continue reading ‘Teardown and Testing of an 800W PureSine Inverter’ »