Understanding and repairing the power supply from a 1969 analog computer

Ken Shirriff writes: We recently started restoring a vintage1 analog computer. Unlike a digital computer that represents numbers with discrete binary values, an analog computer performs computations using physical, continuously changeable values such as voltages. Since the accuracy of the results depends on the accuracy of these voltages, a precision power supply is critical in […]

A look inside a Marconi signal generator

A closer look at a Marconi Instruments signal generator @ jaeblog: Recently I got a Marconi Instruments 2019 signal generator, capable of generating signals from 80Khz up to 1040Mhz. It can also modulate these signals with AM, FM and more. This instrument is from the mid 80s and is, as far as I can test, […]

Teardown of a Spex HS1000 monochromator controller

Kerry Wong did a teardown of a SPEX HS1000 monochromator/spectrometer controller: Monochromator is one of those things that has always fascinated me. Over the years, I have done quite a few experiments (I, II, III) with an EP200Mmd monochromator and it was a lot of fun. Because monochromators are such highly specialized equipment, decent ones […]

Tutorial, experiment and teardown of a 24GHz Doppler radar module

Shahriar posted a detailed analysis of a CDM324 24GHz Doppler radar module from IC Station: Opening the module reveals a series of microwave PCB components and several active devices. A complete analysis of the module is presented. The unit is then measured and the impact of antenna impedance and power supply voltage on the output […]

Inside a Datum 9300 time code generator

Kerry Wong did a teardown of a Datum 9300 time code generator: IRIG time code generators (not to be confused with the ones used in video and film industry) are often used for clock synchronization among various connected equipment and is commonly used in power generation and distribution industry as well as in the military. […]

Silicon die analysis: Inside an op amp with interesting “butterfly” transistors

An excellent in-depth look at theTL084 op amp by Ken Shirriff: Some integrated circuits have very interesting dies under a microscope, like the chip below with designs that look kind of like butterflies. These patterns are special JFET input transistors that improved the chip’s performance. This chip is a Texas Instruments TL084 quad op amp and […]

Siglent SDG6000X Series Arbitrary waveform generator review, teardown and experiments

A closer look at the newly released Siglent SDG6000X Series Arbitrary Waveform Generator from The Signal Path: The full teardown of the unit reveals the internal architecture of the instrument, DAC / FPGA interconnect as well as the output amplifier structure. Although the limitations of the FPGA prevents the instrument to operate at full 2.5GSa/s in arb-mode, […]

Capacitor plague? Inside an HP 8620C sweep oscillator and HP 86245A RF plugin

A teardown of the HP 8620C and HP 86245A by Kerry Wong: 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 […]

Teardown of an HP 8671A microwave frequency synthesizer

Kerry Wong did a 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 […]

IBM mainframe tube module part II: Powering up and using a 1950s key debouncer

Here’s an interesting two-part series of posts by Ken Shirriff detailing the IBM mainframe tube module. Part 1 discuss the tube modules and describe the IBM 705 that used this module. Part 2 covers powering up the module and getting it to work. Read the full post at Ken Shirriff’ blog.

Teardown of an ATVR-1000D AC voltage regulator

Kerry Wong did a teardown of an ATVR-1000D automatic AC voltage regulator and discussed how different types of AC regulators work: The ATVR-1000D utilizes a motor to drive the wiper of a autotransformer (Variac), the servo motor can be driven in either direction depending on the output from the OpAmp (LM324) based comparator. Comparing to […]

A full review of EasyEDA: A circuit EDA online tool

Yahya Tawil wrote in to share his review of a web based EDA tool, the EasyEDA. He explains the general structure of this tool and some of its cool features: EDA cloud tools which are related to electronics are emerging exponentially in almost all aspects (i.e. simulation, PCB design, footprint creation, gerber files viewing and 3D […]

A look inside the DS3231 real-time clock

Pete posted an article taking a closer look at Maxim’s DS3231 real-time clock: Fortunately, Maxim also offers the DS3231, which is advertised as an “Extremely Accurate I2C-Integrated RTC/TCXO/Crystal”. This chip has the 32kHz crystal integrated into the package itself and uses a built-in temperature sensor to periodically measure the temperature of the crystal and, by […]