Vintage Philco Radio Looks Stock, Contains Modern Secret: A Raspberry Pi

Antique radio receivers retain a significant charm, and though they do not carry huge value today they were often extremely high quality items that would have represented a significant investment for their original owners. [CodeMakesItGo] acquired just such a radio, a Philco 37-11 made in 1937, and since it was it a bit of a state he set about giving it some updated electronics. Vintage radio purists, look away from the video below the break.

Stripping away the original electronics, he gave it a modern amplifier with Bluetooth capabilities, and a Raspberry Pi. Vintage radio enthusiasts will wince at his treatment of those classic parts, but what else he’s put into it makes up for the laying waste to a bit of ’30s high-tech.The original tuning dial was degraded so he’s given it a reproduction version, and behind that is an optical encoder and two optical sensors. This is used to simulate “tuning” the radio between different period music “stations” being played by the PI, and for an authentic feel he’s filled the gaps with static. The result is a functional and unusual device, which is probably better suited than the original to a 2019 in which AM radio is in decline.

If you think of a high-end set like this Philco as being the ’30s equivalent of perhaps an 8K TV set, you can imagine the impact of AM radio in those early days of broadcasting. We recently took a look at some of the directional antenna tricks that made so many AM stations sharing the band a possibility.

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Divide To Conquer Capacitive Touch Problems

Back in the day, all of your music was on a shelf (or in milk crates) and the act of choosing what to listen to was a tangible one. [Michael Teeuw] appreciates the power of having music on demand, but misses that physical aspect when it comes time to “put something on”. His solution is a hardware controller that he calls MusicCubes.

Music cube makes selection using RFID, and touching to the right raises the volume level

This is a multi-part project, but the most recent rework is what catches our eye. The system uses cubes with RFID tags in them for each album. This part of the controller works like a charm, just set the cube in a recessed part of the controller — like Superman’s crystals in his fortress of solitude — and the system knows you’ve made your decision. But the touch controls for volume didn’t work as well. Occasionally they would read a false touch, which ends up muting the system after an hour or so. His investigations led to the discovery that the capacitive touch plates themselves needed to be smaller.

Before resorting to a hardware fix, [Michael] tried to filter out the false positives in software. This was only somewhat successful so his next attempt was to cut the large touch pads into four plates, and only react when two plates register a press at one time.

He’s using an MPR121 capacitive touch sensor which has inputs for up to 12-keys so it was no problem to make this change work with the existing hardware. Surprisingly, once he had four pads for each sensor the false-positives completely stopped. The system is now rock-solid without the need to filter for two of this sub-pads being activated at once. Has anyone else experienced problems with large plates as the touch sensors? Can this be filtered easily or is [Michael’s] solution the common way to proceed? Share your own capacitive touch sensor tips in the comments below!

Want to get a look at the entire project? Start with step one, which includes a table of contents for the other build logs.

Yet Another Concrete Speaker Build

Concrete is great if you feel like making something heavy on the cheap. [Marek Unger] decided to have a go, using the material to cast speaker cabinets for a home hi-fi rig (Youtube link, embedded below).

Initial attempts involved creating a laser-cut MDF outer mold, with a styrofoam core inside to be removed later. This was unsuccessful, and [Marek] developed the design further. The second revision used an inner core also made from lasercut MDF, designed to be left inside after casting. This inner mold already includes the mounting holes for the speaker drivers, making assembly easier too.

Once cast, the enclosures were fitted with Tang-Band W4-1320SIF drivers. These are a full-range driver, meaning they can be used without needing crossovers or other speakers to fill in the frequency range. Each cabinet weighs just over 10kg, and they’re ported for extra response in the lower frequency bands. Sound tests are impressive, and the rough-finished aesthetic of the final product looks great in [Marek]’s living room.

We’ve seen concrete used for all manner of projects, from furnaces to USB hubs. Video after the break.

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Finally, A TV For Portrait Videos

Vertical video is bad, or so we’re told, and you shouldn’t shoot a video with your phone in a vertical position. Why? Because all monitors are wider than they are tall. This conventional wisdom is being challenged by none other than Samsung. There is now a vertical TV (Korean, Google Translate link) , engineered specifically videos shot on mobile phones.

“Samsung Electronics analyzed the characteristics of the Millennial generation, which is familiar with mobile content, and presented a new concept TV ‘The Sero’ (loosely translated as ‘The Vertical’), which is based on the vertical screen, unlike the conventional TV,” so goes the press release.

Features of The Sero TV include synchronization between the screen and a mobile device, and mirroring functions based on NFC. This display is no slouch in the audio department, either: it features a 4.1 channel, 60-watt high-end speaker. A built-in microphone and support for Samsung’s Bixby voice assistant means artificial intelligence can easily control various functions of the display.

The Sero will be released in Korea at the end of May, with a reported price tag of 18,900,000 South Korean Won. A quick Google search tells us that converts to an implausible-sounding $16,295 USD, but it’s not as if you were going to buy one anyway.

Nevertheless, there actually is a market for ‘vertical’ or portrait displays; thanks to the ever-widening of aspect ratios by LCD manufacturers, it makes sense to edit documents with a vertically-oriented monitor. You can fit more code on the screen if you just rotate your monitor. Apple was one of the first companies to realize this with the release of the Macintosh Portrait Display in 1989, providing a wondrous 640×870 grayscale resolution display for desktop publishing. Of course, the Radius full page display was released a few years earlier and the Xerox Alto had a vertically oriented screen. But wait a minute, can’t you just rotate your monitor and save $16k?

Raspberry Pi Revives Stand-Alone DivX Player

It might seem almost comical to our more fresh-faced readers, but there was a time when you could go into a big box retailer and purchase what was known as a “DivX Player”. Though they had the outward appearance of a normal DVD player, these gadgets could read various digital video file formats off of a CD-R or DVD-R, complete with rudimentary file browser. Depending on how much video compression you could stomach, a player like this would allow you to pack an entire season of a show or multiple movies onto a single disc. Before we started streaming everything online, that was kind of a big deal.

Room to grow.

[Roberto Piva] got his hands on one of these early digital media players, a KiSS DP-500 circa 2003, and decided that it was too unique to send off to the recycling center. Not only was he curious about what made it tick, but he thought it would be interesting to try converting it into a Raspberry Pi powered streaming media player. One might say there’s something almost perverse about taking the carcass of one of these devices and stuffing it full of the same technology that made it obsolete in the first place, but who are we to judge?

Upon opening the vintage set top box, [Roberto] was immediately struck by how empty the thing was. He got the impression the device was a rush job, pushed out to capitalize on a relatively short-lived trend. Looking at it, we have to agree. It’s almost as though they got a deal on some old VCR chassis laying around in a warehouse someplace and decided to stick some (at the time) modern electronics in it. It even uses what appears to be a standard IDE optical drive rather than something purpose built.

[Roberto] hoped that he could tap into the player’s original power supply, but upon testing found that it wasn’t quite up to the task to reliably running a modern Pi. So into the cavernous enclosure went a powered USB hub, which he wired up to the original power switch on the player’s front panel. The original PSU couldn’t handle the Pi, but it does work nicely to spin up an IDE hard drive that he mounted to the top of the optical drive with zip ties.

This was enough to get a nice Kodi set top box that’s capable of pulling media from the Internet or the internal HDD, but [Roberto] has more plans for the future. He wants to try and get the optical drive working through a USB-to-IDE adapter so the device can come full circle and once again play burned discs full of video files, and mentions he would like to reverse engineer the front panel and IR receiver to control Kodi.

While this isn’t the first time we’ve seen a DVD player get an internal Raspberry Pi, the fact that this one is using an IDE drive is an interesting spin and should make for a very clean final product. We’ve also seen how integrating the original physical controls can really help sell the experience with these Pi-infused players. If you’ve got the space in your entertainment for one of these early 2000’s leviathans, they might make an ideal base for your own Pi set top box build.

Infrared Brute Force Attack Unlocks TiVo

While the era of the TiVo (and frankly, the idea of recording TV broadcasts) has largely come to a close, there are still dedicated users out there who aren’t quite ready to give up on the world’s best known digital video recorder. One such TiVo fanatic is [Gavan McGregor], who recently tried to put a TiVo Series 3 recorder into service, only to find the device was stuck in the family-friendly “KidZone” mode.

Without the code to get it out of this mode, and with TiVo dropping support for this particular recorder years ago, he had to hack his way back into this beloved recorder on his own. The process was made easier by the simplistic nature of the passcode system, which only uses four digits and apparently doesn’t impose any kind of penalty for incorrect entries. With only 10,000 possible combinations for the code and nothing to stop him from trying each one of them in sequence, [Gavan] just needed a way to bang them out.

After doing some research on the TiVo remote control protocol, he came up with some code for the Arduino using the IRLib2 library that would brute force the KidZone passcode by sending the appropriate infrared codes for each digit. He fiddled around with the timing and the delay between sending each digit, and found that the most reliable speed would allow his device to run through all 10,000 combinations in around 12 hours.

The key thing to remember here is that [Gavan] didn’t actually care what the passcode was, he just needed it to be entered correctly to get the TiVo out of the KidZone mode. So he selected the “Exit KidZone” option on the TiVo’s menu, placed his Arduino a few inches away from the DVR, and walked away. When he came back the next day, the TiVo was back into its normal mode. If you actually wanted to recover the code, the easiest way (ironically) would be to record the TV as the gadget works its way through all the possible digits.

Back in 2004, there were so many TiVo hacks hitting the front page of Hackaday that we actually gave them a dedicated subdomain. But by the end of 2007, we were asking what hackers would do with the increasingly discarded Linux-powered devices. That people are still hacking on these gadgets over a decade later is truly a testament to how dedicated the TiVo fanbase really is.

[Thanks to Chris for the tip.]

Refurbishing A Classic Electrostatic Speaker PSU

Sometimes a project takes longer than it should to land in the Hackaday in-tray, but when we read about it there’s such gold to be found that it’s worth sharing with you our readers despite its slight lack of freshness. So it is with [Andrew Back]’s refurbishment of his Quad electrostatic speaker system power supply, it may have been published back in August but the glimpse it gives us into these legendary audio components is fascinating.

The inner workings of an electrostatic loudspeaker
The inner workings of an electrostatic loudspeaker

An electrostatic speaker is in effect a capacitor with a very large surface area, of which one plate is a flexible membrane suspended between two pieces of acoustically transparent mesh that form the other plates. A very high DC bias voltage in the multiple kilovolts region is applied across the capacitor, and the audio is superimposed upon it at a peak-to-peak voltage of somewhere under a kilovolt through a step-up transformer from the audio amplifier. There are some refinements such as that the audio is fed as a push-pull signal to the opposing mesh plates and that there are bass and treble panels with different thickness membranes, but these speakers are otherwise surprisingly simple devices.

The problem with [Andrew]’s speakers became apparent when he took a high voltage probe to them, one speaker delivered 3 kV from its power supply while the other delivered only 1 kV. Each supply took the form of a mains transformer and a voltage multiplier board, so from there it became a case of replacing the aged diodes and capacitors with modern equivalents before applying an insulating layer for safety.

Electrostatic speakers are no stranger to Hackaday, we’ve taken an in-depth look at them in the past. You may also find some of our colleague [Steven Dufresne]’s writing on the matter to be of interest, on measuring high voltages, and his experience wrangling high voltage.