Kerry D. Wong

I just picked up another high voltage power supply, this time it is a working Bertan/Spellman 225-20R 20kV one. Unlike the Bertan 205A-05R that I did a teardown with last time which was entirely analog, this one can be controlled digitally either via the front panel or via GPIB from the back. In this blog post, let me share some of the teardown pictures with you. If you are interesting in seeing some cool experiments with this high voltage power supply, you can scroll down and watch my video towards the end. Continue reading ‘Bertan/Spellman 225-20R HV Power Supply Teardown’ »

I recently was given a broken Epson PowerLite 84 projector. The projector would not turn on when plugged in and there was no sign of life. So I decided to take a look at what was wrong with it. The potential reward is high since I do not have a projector yet and I could definitely use one for my home theater setup. A video of this teardown and repair is linked towards the end. Continue reading ‘Epson PowerLite 84 Multimedia Projector Teardown and Repair’ »

I bought a non-working Lambda LQ-521 linear power supply on eBay a couple of weeks ago. Usually I avoid knowingly buying something that is broken unless I am certain that I could obtain parts for it at a reasonable price. But buying broken linear power supplies is another story as most of the problem can be fixed with readily available components. Continue reading ‘Lambda LQ-521 Power Supply Teardown and Repair’ »

I did a teardown of an RSA SecurID many years ago (you can see that post here). In that teardown, it was an older generation (SD600) of the RSA SecurID. In this post, let’s take a look at what’s inside the newer SID700 series RSA SecurID token. A short video of the teardown is included towards the end. Continue reading ‘RSA SecurID Teardown’ »

I did a teardown video of a microwave range (8-10 GHz) RF isolator last week. As a follow up, I will post some of the high-resolution pictures I took during the process here (click to see larger images). Continue reading ‘Teardown of an 8-10 GHz RF Isolator’ »

Today at a time when digital storage oscilloscopes (DSO) are almost ubiquitous, analog scopes like Tektronix 2465 remain popular among many electronics hobbyists, especially among amateur radio operators who routinely work with high frequency circuits. I got my 2465 from ValueTronics. For those who haven’t heard about them, I would recommend you check them out as they have a large selection of used test equipment at reasonable prices. Continue reading ‘Teardown of a Tektronix 2465’ »

The latest addition to my lab is an HP 8566B spectrum analyzer. This isn’t just any spectrum analyzer, it was perhaps the best spectrum analyzer money could buy back in the late 80’s. While it was discontinued in 1997 and has long become obsolete, its performance remains quite impressive even by today’s standards and still rivals that of many of its modern counterparts. Continue reading ‘Some Pictures of My HP 8566B Spectrum Analyzer’ »

In this blog post, we are going to take a look at Electronic Development Corporation’s (EDC, acquired by Krohn-Hite in 1998) MV216A battery/external powered DC voltage standard and also measure its voltage reference’s temperature coefficient (tempco). A teardown video is also included towards the end. MV216A is a six decade precision DC voltage standard, it can output from 0.1µV in 100mV range all the way up to 11.1111V in 10V range. Voltage standards of this caliber are usually used as calibrators to calibrate multimeters and other test instruments. Continue reading ‘EDC/Krohn-Hite MV216A DC Voltage Standard Teardown and Tempco Measurement’ »

This old Cisco switch was on its way to the dumpster at my work place, so I thought I would rescue it. After all, while there are plenty of teardowns of consumer grade networking gear on the internet, teardowns of enterprise level network equipment have been hard to come by. So at the very least it would be a good opportunity to take a good peek inside. Continue reading ‘Teardown of a Cisco CSS 11503 Content Services Switch’ »

I bought a Wavetek 1045 RF power meter off eBay a few weeks ago. It came with a 13787 detector which is capable of measuring RF power between -50 dBm to 10 dBm with a frequency range of 1 MHz to 18 GHz. Continue reading ‘Wavetek 1045 RF Power Meter Teardown’ »

Traveling-wave tube (TWT) is mainly used to amplify signals in the microwave frequency range. Unlike most vacuum tubes, which had largely given way to their more elegant semiconductor counterparts many decades ago, TWT is still being widely used today in many areas, especially in places where low noise and high output power is needed. I had always wanted to get my hands on one so when I saw an old HP 493A microwave amplifier for sale for peanuts, I simply could not resist snatching it. Continue reading ‘T is for TWT’ »

In my last post, I showed my LED backlight mod of the HP 8642B synthesized signal generator. And during the process, I also showed some pictures of the A1 (keyboard and LCD) module and A2 (modulator) module alone with an intriguing Easter egg message in the firmware. In today’s post, I will do a full teardown of each module and take a closer look at what’s inside. Continue reading ‘HP 8642B Teardown Pictures’ »

Since I just got myself an HP 5350B microwave counter and I had fixed it up, I thought it would be great if I could get a SHF generator to test out the counter in the microwave range. So when I saw a super cheap Wavetek 907 for sale on eBay, I simply could not pass it up. Continue reading ‘Wavetek 907 Signal Generator Teardown’ »

Dave did an analog multimeter teardown in his latest episode. I have a Chinese made MF 10A multimeter bought back in the 90’s and thought I’d do a teardown to take a look at what is inside. Continue reading ‘MF 10A Analog Multimeter Teardown’ »

A few days ago, I bought a Keithley 197 sold as “unknown working condition” on the cheap. The seller said that some of the keys on the meter were unresponsive. I figured that I’d try fixing it if I could. After all, these 5 ½ meters still fetch well over $100 on eBay and for a fraction of that price, I was willing to give it a shot. Continue reading ‘Keithley 197 Teardown and Repair’ »