Retro PC Update 2

I installed Windows 98 Second Edition and it is a blast from the past for sure. It took a while to get all of the hardware working and figured out I don’t have a ATI All in Wonder but a ATI TV Wonder VE. I can’t find the ATI Multimedia Center that is compatible however VLC works well. So for giggles I tossed on my Arduino Voltmeter that uses the TV out add-on. I’m currently installing SmartDraw and I’ll attempt to install some updates and try out the KernelEX add-on and see about getting a HTML5 compatible browser going. After that I’ll get DOS 6.22 going for some DOS gaming.

A couple of hurdles had came my way like transferring files from my Win7 driven laptop. I had to waste a CD for a simple 400KB driver set for the Ethernet card. After that I just created a file share on the Retro PC and copied files over that way. I also couldn’t get the built-in sound working so I tossed in a SoundBlaster Live Value PCI card. Every USB device I plug in is “too new” and it complains for drivers. There is a Unofficial Service Pack that has all of the updates from the old Windows Update site from back in the day. Maybe after installing that I can get further with USB support for my old 256MB jump drive.

Retro PC Project update

I slapped together a Intel Celeron as my “Retro PC”. It works very well and can run all the games and programs I want from back in the day.

Here are the specs of the system.
Intel Celeron 700MHz
512MB RAM
Maxtor 120GB PATA drive
Iomega 250 PATA drive
1.44MB Floppy
Realtek Ethernet
ATI All in Wonder
A-Open desktop case

As I said with this setup I can run almost anything from the old days and even have enough hard drive space to boot different operating systems.

A few snags on the build hasn’t made my day. The Power supply kept shorting out and come to find out it was the Optical drive. So now I need to replace it and the only other PATA/IDE drive I have is a DVD drive. A while back I bought a unopened box of floppies and I finally found my old USB floppy drive. Sadly all of the disks do not work. I get write protection issues on my main system and the Retro PC  complains about Sector Zero. So maybe today or Tuesday I’ll swing by the other Thrift store I go to often for old PC hardware and see if they still have some sealed boxes of Memorex floppies. The box that test bad before were some Neon colored floppies from CompUSA.

When I get this system up and running I’ll probably pull out mt Mechanical keyboard and play some DOOM and Duke Nukem. After that hunt down a copy of Railroad Tycoon or build my Parallel protoboard and control some relays or something.

Add some vintage old school looks to your modern projects

I have been looking at old vintage electronics and saw some things that you don’t see anymore. I’m not talking about Vacuum tubes or discontinued solid state stuff but Chassis, Cases and Wire management.

I want to focus on the Wire Management. Reason why is because it’s basically a dead art and mostly used these days by line men and aircraft.

Before we had Zip-Ties or Zap Straps wire was laced together with wax-coated string. It was called Cable Lacing and was really big with telecommunications and used in high-end equipment. There are even a few different styles for the lacing, NASA even has their own techniques that can be found in chapter 9 of NASA-STD-8739.4.

The lacing begins and ends with a whipping or other knot to secure the free ends. Wraps are spaced relative to the overall harness diameter to maintain the wiring in a tight, neat bundle, and the ends are then neatly trimmed. In addition to continuous or running lacing, there are a variety of lacing patterns used in different circumstances. In some cases stand-alone knots called spot ties are also used. For lashing large cables and cable bundles to support structures in telecommunications applications.

800px-cable_lacing_close-up_2

Above is a prime example on how it looks. In my opinion it looks better than Zip Ties and keeps everything much neater. To achieve the same look with Zip Ties you would have to use a huge bag of them to cover ten feet of cable. Not to mention Zip Ties can crush the wire strains and you have to deal with the sharp ends left over when you cut off the excess plastic from the Zip Ties. Electrical tape just makes things nasty after a while when the tape looses its sticky adhesive.

I imagine this would look killer for decked out Gaming PCs and such if you use a color scheme. It could even come in handy for cleaning up the wire mess under your computer desk or Livingroom entertainment center.

HP Touchsmart update

I got a HP TouchSmart tx2-1025dx not to long ago from a friend.

The system didn’t have a charger and would you know it HP had to use a odd ball metric size barrel plug/jack combo. I had a old off brand charger from Delta Electronics that is the correct voltage and amp rating so I went digging in my big box of wall warts. I finally found a jack that fits so I just simply cut the barrel jack from the charger and attached the plug from some crappy 12volt wall wart that had the proper size. I soldered and used heat shrink on the joint.

Since the system also didn’t have a hard drive all I had in my inventory was a 160GB drive I pulled from a old Apple. So for now I tossed on Windows 7 just so I can get another working system here for next Friday night when the Kids and I have a little LAN party with Quake.

Guitar Amp failure

I was given a Kustom Kasino 400 Guitar amp a while back. It only had one previous owner. The manufacturing date was sometime in 1977. It was stored for many years with a cover on it and the cabinet looks almost new. However father time has rein havoc on the electronics.

I’ve opened up the power head a couple of times but never really gave it a good look over until yesterday when I was going to start on modifying the amp to use a new three prong power cable, change the filter cap to a proper X/Y type and clean the controls. However when I started to move wires the sheathing was crumbling off. The wire was oxidized and couldn’t hold solder. I went to remove the main amplifier’s circuit board so I can replace the wiring but every inch of copper was corroded and on further inspection the traces were pulling up from the board.

For giggles I pulled a couple of resistors and tested them. Since they were the brown Carbon-comp style. Sure enough all out of tolerance.

However the speakers are in great shape and the Power Module that was bolted to the bottom of the cabinet is also in fine shape.

So instead of giving my wife grief oh a huge amp the doesn’t work in the living room I called up my oldest friend and asked if he wanted the cabinet since it’s in very nice shape and the speakers look almost new. He jumped at the chance.

Capacitor Leak Tester 3

I built up the circuit on the bread board but I am having some Bias issues. So I went back to the drawing board and pulled out some books and did some hunting around on the web. After much head scratching it hit me. There is a very simple variable voltage circuit that is used in modern power amps. Nothing more than a N-Channel MOSFET, A POT, some resistors and a Zener Diode.

new-schematic-3

Works great and pretty much any N-Channel MOSFET will do as long as the voltage threshold is with in spec of the input voltage. If anything just toss on a 600v rated MOSFET.

To make things even better I came across a four-part YouTube video series from M Caldeira that uses the exact circuit for his Capacitor Leak Tester. So since I know his circuit works I am going to use it.

new-schematic-2

I’ve changed a few values to work for a maximum of 50V instead of his 338V. Since I don’t play with high voltage stuff like Tube equipment.
I’m still using a huge 7 watt 1.2 ohm resistor for the discharge since just shorting it out could harm the cap. I might have to change the bleed resistor to a lower value on the power supply side.

A few nifty points on the power supply side of the circuit. The 100ohm resistor after the Rectifier is to protect the whole circuit from inrush current. The 1.6K Resistor and 1n4007 Diode are there for protection. So if the Capacitor under test is shorted it will only let the transformer push out 30mA and the Diode will block any voltage going back into the power supply causing the Zener to push voltage/current into the Gate of the MOSFET.

DIY Capacitor Leak Tester 2

After much debate when I was over at the bench I found a popper Transformer that can output 50 volts after rectification. Even with a load on it the 1000uF cap I used as a filter was able to hold on. However the analog meter I wanted to use that I pulled from a battery charger will not work. Even with 1 amp passing through it only deflected slightly. However the analog meter that I pulled from a old multi-meter works well but it has no enclosure. If anything I could just get a new/used meter.

When I was hunting down parts I got another idea. Instead of having two momentary switches I could use one switch, a small cap for delay with and couple transistors to invert. This way when I hook up a cap to the tester and it will automatically discharge the cap and when the button is pushed it will disconnect the discharge circuit while the main circuit adds the DC charge to the cap. Since we only need to pump the cap with DC current enough to fill the cap and see how well it blocks the DC (IE Leak test). At the same time I attend to over think things and should keep it simple.

The Transformer I have here has multiple taps. One set I can test 25V rated caps and the other set I can test 50V rated caps. So I would need a DPDT switch to switch between the taps. Or I could just add another circuit and a rotary switch to switch between voltage values.

In the future I can always swap out the transformer to test higher voltage rated capacitors.

Now you don’t need to build a device like I am. You can use a Bench PSU and a Multi-meter to test a Capacitor. Just put the Multi-meter in the Amps setting and put it in series with the PSU’s positive side. Connect the negative Probe from the Multi-meter to the positive side of the Capacitor under test. Connect negative side of the Capacitor to the Power Supply’s ground. Crank up the voltage to the Capacitor’s rated voltage and you’ll get the result. However this will leave the Capacitor fully charged and you’ll need to discharge it after the test. A high wattage low ohm Resistor will work fine or if you’re daring you could just short it out with a screw driver. When you’re testing Ceramic and Film Capacitors they don’t have to be discharged. You just have to worry about electrolytic Capacitors that hold a charge. The only time you need to worry about non-electrolytic type of Capacitors is if they’re older then you. Such as Vacuum Tube equipment or early solid state equipment. Typically today you can go about the ESR value of most Ceramic and Film Capacitors. Most of the time Electrolytic Capacitors will wear out over time. All depends on how they’re used and how cool they’re kept under load.

Sparkfun has a huge article about Capacitors. Also a YouTuber Mr Carlson’s Lab has much to offer on Capacitors for vintage equipment and testing.