80s Function Generator Is Both Beauty And Beast

April 23, 2024 by Tom Nardi 11 Comments

You know how the saying goes — they don’t make them like this anymore. It’s arguably true of pretty much any electronic device given the way technology changes over time, though whether or not it’s objectively a bad thing is going to vary from case to case.

As a practical example, take a look at the insides of this 80’s vintage HP 3314A function generator shared on the EEV Blog Forum by [D Straney].

With multiple PCBs stacked on top of each other, it’s hard to imagine that more components could possibly be crammed into it. One board in particular appears to be an entire Motorola 6800 computer, something which today would likely be replaced with a single microcontroller.

Which is actually why [D Straney] shared this with us in the first place. After seeing our recent post about a modern waveform generator that’s basically an empty box thanks to its modern components, they thought this would be a nice example of the opposite extreme.

So, is it a good or a bad thing that test equipment isn’t made this way anymore? Well, it’s hard to argue with the improved capabilities, smaller footprint, and reduced cost of most modern gear. But damn is the inside of this HP 3314A gorgeous. As one of the commenters on the page put it, hardware from this era was really a work of art.

Early CD Player Teardown

April 18, 2024 by Al Williams 16 Comments

While CD players are nothing new today, they were the height of high-tech in the early 1980s. [w1ngsfly] shows us the inside of a Phase Linear 9500 player from 1983. Not only does it have many components, but it is also mechanically unusual.

The CD loads into a toaster-like slot and even pops out like a piece of toast. The tracking mechanism is quite complex, and there’s something that looks suspiciously like a dial string from an old slide rule tuner radio. Apparently, the unit was made by Kyocera and is internally similar to a Kyocera DA-01.

There’s a “head position” indicator that is actually just an LED connected to the tracking mechanism. The front panel controls look great but also allow you to control the head position exactly. As [w1ngsfly] mentions, it is almost like moving a turntable’s tonearm where you can drop it anywhere you want.

If we recall, they were about $600 to $1,000 new. If Phase Linear doesn’t ring a bell, they were well known in their day. Founded by [Bob Carver] and [Steve Johnston], the company was bought by Pioneer before the introduction and, later, by Jensen before the introduction of the 9500. [Bob] would go on to found Carver Corporation. You can find plenty of history about the company online.

We’ve seen CD players that look older. These days, CD drives are cheap and they are easy enough to control.

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Hacked Oscilloscope Plays Breakout, Hints At More

April 18, 2024 by Dan Maloney 8 Comments

You know things are getting real when the Dremel is one of the first tools you turn to after unboxing your new oscilloscope. But when your goal is to hack the scope to play Breakout, sometimes plastic needs to be sacrificed.

Granted, the scope in question, a Fnirsi DSO152, only cost [David Given] from Poking Technology a couple of bucks. And while the little instrument really isn’t that bad inside, it’s limited to a single channel and 200 kHz of bandwidth, so it’s not exactly lab quality. The big attractions for [David] were the CH32F103 microcontroller and the prominent debug port inside, not to mention the large color LCD panel.

[David]’s attack began with the debug port and case mods to allow access, but quickly ground to a halt when he accidentally erased the original firmware. But no matter — tracing out the pins is always an option. [David] made that easier by overlaying large photos of both sides of the board, which let him figure out which buttons went to which pins, and mapping for the display’s parallel interface. He didn’t mess with any of the analog stuff except to create a quick “Hello, oscilloscope!” program to output a square wave to the calibration pin. He did, however, create a display driver and port a game of breakout to the scope — video after the hop.

We’ve been seeing a lot of buzz around the CH32xx MCUs lately; seeing it start to show up in retail products is perhaps a leading indicator of where the cheap RISC chips are headed. We’ve seen a few interesting hacks with them, but we’ve also heard tell they can be hard to come by. Maybe getting one of these scopes to tear apart can fix that, though.

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Waveform Generator Teardown Is Nearly Empty

April 15, 2024 by Al Williams 26 Comments

We always enjoy [Kerry Wong]’s insightful teardowns, and recently, he opened up a UTG1042X arbitrary waveform generator. Getting inside was a bit of a challenge since there were no visible screws. Turns out, they were under some stickers. We always dislike that because it is very difficult to get the unit to go back together.

Once open, the case reveals it is almost completely empty. The back panel has a power supply, and the front panel has all the working circuitry. The box seems to be for holding the foot and preventing the device from getting lost on your bench.

The power supply is unremarkable. There are a few odd output voltages. The main board is a bit more interesting, especially after removing the heat sink. There are two channels, but the board isn’t laid out, with a lot of segregation between the two channels. That makes sense with the output sections clustered together and the digital section with the CPU, FPGA, and the DAC in close proximity.

The other side of the board connects to a very simple display board. It would be interesting to compare this to a circa-1980s AWG, which would have been far more complicated.

Making a waveform generator with a microprocessor and a DAC isn’t hard. The hard part is the output stages and maximizing the operating speed.

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Voice Control For A Vintage Heathkit Radio

April 14, 2024 by Al Williams 6 Comments

Most modern ham rigs have a voice activated transmission (VOX) mode, although we don’t know many people who use it often. When a transmitter is in VOX mode, it starts transmitting when you talk, and then, when you pause for a second or two, the transmitter turns off. Many old ham transmitters, though, didn’t support VOX, so Heathkit sold the VX-1 “electronic voice control” to add VOX to older transmitters. [Jeff Tranter] shows us inside a clean-looking unit.

These devices were sold from 1958 to 1960 and used tubes and a selenium rectifier. The device is connected between the microphone and the transmitter. It also sat between the receiver and the speaker to mute audio while transmitting. The original unit had a screw terminal to connect to the outside world, and some of the screws had live line voltage on them. The unit [Jeff] examines is modified to have phono jacks along with a few other repairs.

The wiring looks like a tube radio. Tubes are above the chassis, and point-to-point wiring is underneath. There is also an unusual sealed selenium rectifier. [Jeff] shows how the device works using just a receiver. A few minor repairs were needed.

If you are interested in getting your ham license, most modern radios support VOX out of the box — no rhyme intended. We do, however, love that old Heathkit gear.

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Danish Vintage LRC Meter Reveals Inside

April 14, 2024 by Al Williams 7 Comments

Modern test equipment is great, but there’s something about a big meter with a swinging needle and a mirror for parallax correction that makes a device look like real gear. [Thomas] shows us a Danish LCR meter (or, as it says on the front, an RLC meter). The device passes AC through the component and uses that to determine the value based on the setting of a range switch. It looks to be in great shape and passed some quick tests. Have a look at it in the video below.

An outward inspection shows few surprises, although there is an odd set of terminals on the back labeled DC bias. This allows you to provide a DC voltage in case you have a capacitor that behaves differently when the capacitor has a DC voltage across it. Continue reading “Danish Vintage LRC Meter Reveals Inside” →

Vintage Particle Counter Is A Treasure Trove Of Classic Parts

April 13, 2024 by Dan Maloney 1 Comment

If you need a demonstration of just how far technology has come in the last 40 years, just take a look at this teardown of a 1987 laser particle counter.

Granted, the laser-powered instrument that [Les Wright] scored off of eBay wasn’t exactly aimed at consumers. Rather, this was more likely an instrument installed in cleanrooms to make sure the particulate counts didn’t come out of range. As such, it was built like a battleship in a huge case stuffed with card after card of electronics, along with the attendant pumps and filters needed to draw in samples. But still, the fact that we can put essentially the same functionality into a device that easily fits in the palm of your hand is pretty striking.

[Les] clearly bought this instrument to harvest parts from it, and there’s a ton of other goodness inside, including multiple copies of pretty much every chip from the Z80 family. The analog section has some beautiful Teledyne TP1321 op-amps in TO-99 cans. Everything is in immaculate condition, and obsolete or not, this is an enviable haul of vintage parts, especially the helium-neon laser at its heart, which still works. [Les] promises an in-depth look at that in a follow-up video, but for now, he treats us to a little tour of the optics used to measure particulates by the amount of laser light that’s scattered.

All things considered, [Les] really made out well on this find — much better than his last purchase.

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