Teardown of a Marconi 2305 modulation meter

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Kerry Wong did a teardown of a Marconi 2305 modulation meter:

I picked up a Marconi 2305 modulation meter off eBay the other day. As the name indicated, a modulation meter is used to measure the modulation characteristics of a source signal. The Marconi 2305 is capable of measuring amplitude/frequency and phase modulated signals from a few hundred kHz all the way up to 2 GHz.
The Marconi 2305 was built sometime between the late 70’s and 80’s. It is a pity that the iconic British Marconi Instruments went under in 1998 and had since changed hands a couple of times.

See the full post on his blog.

Check out the video after the break.

Teardown of a LogiMetrics A300/S traveling wave tube amplifier

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 LogiMetrics A300/S TWTA teardown by Kerry Wong:

I just picked up a LogiMetrics A300/S 2 GHz to 4 GHz (S band) traveling wave tube amplifier (TWTA) on eBay. I had done an extreme teardown of an HP 493A TWTA a while ago and it was quite fascinating to see what’s inside of a TWT. This LogiMetrics A300/S was made from the late 70’s and unlike the HP 493A it was made entirely using solid state devices (e.g. transistors and ICs), the TWT itself of course remains a vacuum tube.

See the full post on his blog.

Check out the video after the break.

Teardown of a Spex HS1000 monochromator controller

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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 are hard to come by at reasonable prices second hand. So my strategy has been to scour eBay once a while and pick up bit and pieces whenever I can.

See the full post on his blog.

Check out the video after the break.

Teardown of a Piezoelectric vibrating gyroscope

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Kerry Wong did a teardown of an old analog piezoelectric vibrating gyroscope:

Gyroscopes nowadays are based on micro-electro-mechanical systems (MEMS) technology. They are low cost and extremely miniaturized. A device combing both a three-axis gyroscope and a three-axis accelerometers (sometimes these devices are referred to as 6DOF devices) such as the MPU-6500 for example can be had in a QFN package as small as 3 mm x 3 mm and under 1 mm in height. Before these MEMS devices gained mainstream popularity however, larger piezoelectric vibrating gyroscopes were used in many consumer electronics devices.

See the full post on his blog.

Check out the video after the break.

Dashcam GPS module

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A look at the Dashcam GPS module by Electronupdate:

After a 4 year run the dashcam on my car stopped working: a fault seems to have developed in the power system.  It was mounted to the window by what I thought was just a simple mechanical mount… on further analysis it became clear that the GPS receiver was part of the mount (makes sense as the user normally glues this part to the windscreen).

More details on Electronupdate blog.

Check out the video after the break.

Teardown and repair of an GW Instek PSW80-40.5 1080W multi-range programmable power supply

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Teardown and repair of an GW Instek 1080W power supply from The Signal Path:

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.

More details on The Signal Path site.

Check out the video after the break.

Teardown of an Array 3711A 300W DC electronic load

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Kerry Wong did a teardown of an Array 3711A 300W electronic load:

I have made many electronic loads in the past. For instance this simple harddrive cooler housed small dummy load, this more sophisticated constant current/constant programmable load and this heavy-duty electronic load that is capable of sinking over 1kW under peak load. In this blog post though, I am going to take a look inside an Array 3711A DC electronic load I recently purchased on eBay. You can find a video of this teardown towards the end of the post.

See the full post on his blog here.

Check out the video after the break.

Inside a two-quadrant power supply – Agilent 66312A teardown and experiment

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Kerry Wong did a teardown of an Agilent 66312A dynamic measurement DC source:

Typically, a lab power supply can only operate within a single quadrant. Take a positive voltage power supply for example, it can only output or source current. If any attempt is made trying to sink current into the power supply by connecting a voltage source with a higher voltage than the output voltage of the power supply, the power supply would lose regulation since it cannot sink any current and thus is unable to bring down and regulate the voltage at its output terminals.
The Agilent 66312A dynamic measurement DC source however is a two-quadrant power supply, it not only can source up to 2A of current between 0 and 20V, but also can sink up to 1.2A or 60% of its rated output current as well. Although lacking some key functionality of a source measure unit (SMU), Agilent 66312A can nevertheless be used in similar situations where both current sourcing and sinking capabilities are needed.

More details on Kerry Wong’s blog.

Check out the video after the break.

Glowing mercury thyratrons: Inside a 1940s Teletype switching power supply

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Ken Shirriff take a look inside a bulky DC power supply REC-30 rectifier, how it works and contrast it with a MacBook power supply:

We recently started restoring a Teletype Model 19, a Navy communication system introduced in the 1940s.14 This Teletype was powered by a bulky DC power supply called the “REC-30 rectifier”. The power supply uses special mercury-vapor thyratron tubes, which give off an eerie blue glow in operation, as you can see below.
The power supply is interesting, since it is an early switching power supply. (I realize it’s controversial to call this a switching power supply, but I don’t see a good reason to exclude it.) While switching power supplies are ubiquitous now (due to cheap high-voltage transistors), they were unusual in the 1940s. The REC-30 is very large—over 100 pounds—compared to about 10 ounces for a MacBook power supply, demonstrating the amazing improvements in power supplies since the 1940s. In this blog post, I take a look inside the power supply, discuss how it works, and contrast it with a MacBook power supply.

See the full post on Ken Shirriff ‘s blog.